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<h1 id="firstHeading" class="firstHeading" lang="en">Prime meridian</h1>
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<div id="siteSub">From Wikipedia, the free encyclopedia</div>
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<div id="mw-content-text" lang="en" dir="ltr" class="mw-content-ltr"><div role="note" class="hatnote">"Prime Meridian" redirects here. For the meridian often called the Prime Meridian, see <a href="/wiki/Prime_meridian_(Greenwich)" title="Prime meridian (Greenwich)">Prime meridian (Greenwich)</a>.</div>
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<div style="position:relative;width:300px;border:1px solid lightgray"><a href="/wiki/File:Earthmap1000x500compac.jpg" class="image" title="Line across the Earth"><img alt="Line across the Earth" src="//upload.wikimedia.org/wikipedia/commons/thumb/c/c4/Earthmap1000x500compac.jpg/300px-Earthmap1000x500compac.jpg" width="300" height="150" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/c/c4/Earthmap1000x500compac.jpg/450px-Earthmap1000x500compac.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/c/c4/Earthmap1000x500compac.jpg/600px-Earthmap1000x500compac.jpg 2x" data-file-width="1000" data-file-height="500" /></a>
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<div style="position: absolute; z-index: 4; left: 0.5em; text-align: left; top: 48%"><span style="background:#FFFFFF;padding:0 2px;color:black">0°</span></div>
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<b>Prime Meridian</b></div>
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</div>
<p>A <b>prime meridian</b> is a <a href="/wiki/Meridian_(geography)" title="Meridian (geography)">meridian</a> (a line of <a href="/wiki/Longitude" title="Longitude">longitude</a>) in a <a href="/wiki/Geographical_coordinate_system" class="mw-redirect" title="Geographical coordinate system">geographical coordinate system</a> at which longitude is defined to be 0°. Together, a prime meridian and its antimeridian (the <a href="/wiki/180th_meridian" title="180th meridian">180th meridian</a> in a <a href="/wiki/Degree_(angle)" title="Degree (angle)">360°-system</a>) form a <a href="/wiki/Great_circle" title="Great circle">great circle</a>. This great circle divides the sphere, e.g., the <a href="/wiki/Earth" title="Earth">Earth</a>, into two <a href="/wiki/Hemisphere_of_the_Earth" class="mw-redirect" title="Hemisphere of the Earth">hemispheres</a>. If one uses directions of East and West from a defined prime meridian, then they can be called <a href="/wiki/Eastern_Hemisphere" title="Eastern Hemisphere">Eastern Hemisphere</a> and <a href="/wiki/Western_Hemisphere" title="Western Hemisphere">Western Hemisphere</a>.</p>
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<div class="thumbinner" style="width:222px;"><a href="/wiki/File:Atlas_Cosmographicae_(Mercator)_033.jpg" class="image"><img alt="" src="//upload.wikimedia.org/wikipedia/commons/thumb/6/6f/Atlas_Cosmographicae_%28Mercator%29_033.jpg/220px-Atlas_Cosmographicae_%28Mercator%29_033.jpg" width="220" height="161" class="thumbimage" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/6/6f/Atlas_Cosmographicae_%28Mercator%29_033.jpg/330px-Atlas_Cosmographicae_%28Mercator%29_033.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/6/6f/Atlas_Cosmographicae_%28Mercator%29_033.jpg/440px-Atlas_Cosmographicae_%28Mercator%29_033.jpg 2x" data-file-width="3700" data-file-height="2700" /></a>
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<a href="/wiki/Gerardus_Mercator" title="Gerardus Mercator">Gerardus Mercator</a> in his <i><a href="/wiki/Atlas_Cosmographicae" class="mw-redirect" title="Atlas Cosmographicae">Atlas Cosmographicae</a></i> (1595) uses a prime meridian somewhere close to <a href="/wiki/25th_meridian_west" title="25th meridian west">25°W</a>, passing just to the west of <a href="/wiki/Santa_Maria_Island_(Azores)" class="mw-redirect" title="Santa Maria Island (Azores)">Santa Maria Island</a> in the <a href="/wiki/Atlantic" class="mw-redirect" title="Atlantic">Atlantic</a>. His 180th meridian runs along the <a href="/wiki/Strait_of_Ani%C3%A1n" title="Strait of Anián">Strait of Anián</a> (Bering Strait)</div>
</div>
</div>
<p>A prime meridian is ultimately arbitrary, unlike an <a href="/wiki/Equator" title="Equator">equator</a>, which is determined by the axis of rotation—and various conventions have been used or advocated in different regions and throughout history.<sup id="cite_ref-1" class="reference"><a href="#cite_note-1">[1]</a></sup></p>
<p></p>
<div id="toc" class="toc">
<div id="toctitle">
<h2>Contents</h2>
</div>
<ul>
<li class="toclevel-1 tocsection-1"><a href="#History"><span class="tocnumber">1</span> <span class="toctext">History</span></a></li>
<li class="toclevel-1 tocsection-2"><a href="#List_of_prime_meridians_on_Earth"><span class="tocnumber">2</span> <span class="toctext">List of prime meridians on Earth</span></a></li>
<li class="toclevel-1 tocsection-3"><a href="#International_prime_meridian"><span class="tocnumber">3</span> <span class="toctext">International prime meridian</span></a>
<ul>
<li class="toclevel-2 tocsection-4"><a href="#Prime_meridian_at_Greenwich"><span class="tocnumber">3.1</span> <span class="toctext">Prime meridian at Greenwich</span></a></li>
<li class="toclevel-2 tocsection-5"><a href="#IERS_Reference_Meridian"><span class="tocnumber">3.2</span> <span class="toctext">IERS Reference Meridian</span></a>
<ul>
<li class="toclevel-3 tocsection-6"><a href="#List_of_places"><span class="tocnumber">3.2.1</span> <span class="toctext">List of places</span></a></li>
</ul>
</li>
</ul>
</li>
<li class="toclevel-1 tocsection-7"><a href="#Prime_meridian_on_other_planetary_bodies"><span class="tocnumber">4</span> <span class="toctext">Prime meridian on other planetary bodies</span></a></li>
<li class="toclevel-1 tocsection-8"><a href="#See_also"><span class="tocnumber">5</span> <span class="toctext">See also</span></a></li>
<li class="toclevel-1 tocsection-9"><a href="#Notes"><span class="tocnumber">6</span> <span class="toctext">Notes</span></a></li>
<li class="toclevel-1 tocsection-10"><a href="#References"><span class="tocnumber">7</span> <span class="toctext">References</span></a></li>
<li class="toclevel-1 tocsection-11"><a href="#Further_reading"><span class="tocnumber">8</span> <span class="toctext">Further reading</span></a></li>
<li class="toclevel-1 tocsection-12"><a href="#External_links"><span class="tocnumber">9</span> <span class="toctext">External links</span></a></li>
</ul>
</div>
<p></p>
<h2><span class="mw-headline" id="History">History</span><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Prime_meridian&action=edit&section=1" title="Edit section: History">edit</a><span class="mw-editsection-bracket">]</span></span></h2>
<div role="note" class="hatnote">See also: <a href="/wiki/History_of_longitude" title="History of longitude">History of longitude</a></div>
<div class="thumb tright">
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<div class="magnify"><a href="/wiki/File:Ptolemy-World_Vat_Urb_82.jpg" class="internal" title="Enlarge"></a></div>
Ptolemy's 1st projection, redrawn under <a href="/wiki/Maximus_Planudes" title="Maximus Planudes">Maximus Planudes</a> around 1300, using a prime meridian east of Africa</div>
</div>
</div>
<p>The notion of longitude was developed by the <a href="/wiki/Greeks" title="Greeks">Greek</a> <a href="/wiki/Eratosthenes" title="Eratosthenes">Eratosthenes</a> (c. 276 BC – c. 195 BC) in <a href="/wiki/Alexandria" title="Alexandria">Alexandria</a> and <a href="/wiki/Hipparchus" title="Hipparchus">Hipparchus</a> (c. 190 BC – c. 120 BC) in <a href="/wiki/Rhodes" title="Rhodes">Rhodes</a> and applied to a large number of cities by the <a href="/wiki/Geographer" title="Geographer">geographer</a> <a href="/wiki/Strabo" title="Strabo">Strabo</a> (64/63 BC – c. 24 AD). But it was <a href="/wiki/Ptolemy" title="Ptolemy">Ptolemy</a> (c. AD 90 – c. AD 168) who first used a consistent meridian for a world map in his <a href="/wiki/Geographia_(Ptolemy)" class="mw-redirect" title="Geographia (Ptolemy)">Geographia</a>.</p>
<p>Ptolemy used as his basis the "<a href="/wiki/Fortunate_Isles" title="Fortunate Isles">Fortunate Isles</a>", a group of islands in the <a href="/wiki/Atlantic_Ocean" title="Atlantic Ocean">Atlantic</a> which are usually associated with the <a href="/wiki/Canary_Islands" title="Canary Islands">Canary Islands</a> (13° to 18°W), although his maps correspond more closely to the <a href="/wiki/Cape_Verde" title="Cape Verde">Cape Verde islands</a> (22° to 25° W). The main point is to be comfortably west of the western tip of <a href="/wiki/Africa" title="Africa">Africa</a> (17.5° W) as negative numbers were not yet in use. His prime meridian corresponds to 18° 40' west of <a href="/wiki/Winchester" title="Winchester">Winchester</a> (about 20°W) today.<sup id="cite_ref-2" class="reference"><a href="#cite_note-2">[2]</a></sup> At this time the chief method of determining longitude was by using the reported times of <a href="/wiki/Lunar_eclipse" title="Lunar eclipse">lunar eclipses</a> in different countries.</p>
<div class="thumb tright">
<div class="thumbinner" style="width:222px;"><a href="/wiki/File:Worldmap_1529-Ribero.jpeg" class="image"><img alt="" src="//upload.wikimedia.org/wikipedia/commons/thumb/f/f9/Worldmap_1529-Ribero.jpeg/220px-Worldmap_1529-Ribero.jpeg" width="220" height="127" class="thumbimage" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/f/f9/Worldmap_1529-Ribero.jpeg/330px-Worldmap_1529-Ribero.jpeg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/f/f9/Worldmap_1529-Ribero.jpeg/440px-Worldmap_1529-Ribero.jpeg 2x" data-file-width="747" data-file-height="431" /></a>
<div class="thumbcaption">
<div class="magnify"><a href="/wiki/File:Worldmap_1529-Ribero.jpeg" class="internal" title="Enlarge"></a></div>
Diogo Ribeiro's map of 1529, now in the Vatican library</div>
</div>
</div>
<p>Ptolemy's Geographia was first printed with maps at <a href="/wiki/Bologna" title="Bologna">Bologna</a> in 1477 and many early globes in the sixteenth century followed his lead. But there was still a hope that a "natural" basis for a prime meridian existed. <a href="/wiki/Christopher_Columbus" title="Christopher Columbus">Christopher Columbus</a> reported (1493) that the compass pointed due north somewhere in mid-Atlantic and this fact was used in the important <a href="/wiki/Treaty_of_Tordesillas" title="Treaty of Tordesillas">Tordesillas Treaty</a> of 1494 which settled the territorial dispute between <a href="/wiki/Spain" title="Spain">Spain</a> and <a href="/wiki/Portugal" title="Portugal">Portugal</a> over newly discovered lands. The Tordesillas line was eventually settled at 370 leagues west of Cape Verde. This is shown in <a href="/wiki/Diogo_Ribeiro" title="Diogo Ribeiro">Diogo Ribeiro</a>'s 1529 map. <a href="/wiki/S%C3%A3o_Miguel_Island" title="São Miguel Island">São Miguel Island</a> (25.5°W) in the <a href="/wiki/Azores" title="Azores">Azores</a> was still used for the same reason as late as 1594 by <a href="/wiki/Christopher_Saxton" title="Christopher Saxton">Christopher Saxton</a>, although by this time it had been shown that the zero deviation line did not follow a line of longitude.<sup id="cite_ref-3" class="reference"><a href="#cite_note-3">[3]</a></sup></p>
<div class="thumb tright">
<div class="thumbinner" style="width:222px;"><a href="/wiki/File:Atlas_Ortelius_KB_PPN369376781-006av-006br.jpg" class="image"><img alt="" src="//upload.wikimedia.org/wikipedia/commons/thumb/4/4a/Atlas_Ortelius_KB_PPN369376781-006av-006br.jpg/220px-Atlas_Ortelius_KB_PPN369376781-006av-006br.jpg" width="220" height="161" class="thumbimage" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/4/4a/Atlas_Ortelius_KB_PPN369376781-006av-006br.jpg/330px-Atlas_Ortelius_KB_PPN369376781-006av-006br.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/4/4a/Atlas_Ortelius_KB_PPN369376781-006av-006br.jpg/440px-Atlas_Ortelius_KB_PPN369376781-006av-006br.jpg 2x" data-file-width="3000" data-file-height="2194" /></a>
<div class="thumbcaption">
<div class="magnify"><a href="/wiki/File:Atlas_Ortelius_KB_PPN369376781-006av-006br.jpg" class="internal" title="Enlarge"></a></div>
1571 Africa map by Abraham Ortelius, Cabo Verde prime meridian</div>
</div>
</div>
<p>In 1541, <a href="/wiki/Gerardus_Mercator" title="Gerardus Mercator">Mercator</a> produced his famous forty-one centimetre terrestrial globe and drew his prime meridian precisely through <a href="/wiki/Fuertaventura" class="mw-redirect" title="Fuertaventura">Fuertaventura</a> (14°1'W) in the Canaries. His later maps used the Azores, following the magnetic hypothesis. But by the time that <a href="/wiki/Abraham_Ortelius" title="Abraham Ortelius">Ortelius</a> produced the first modern atlas in 1570, other islands such as Cape Verde were coming into use. In his atlas longitudes were counted from 0° to 360°, not 180°W to 180°E as is common today. This practice was followed by navigators well into the eighteenth century.<sup id="cite_ref-4" class="reference"><a href="#cite_note-4">[4]</a></sup> In 1634, <a href="/wiki/Cardinal_Richelieu" title="Cardinal Richelieu">Cardinal Richelieu</a> used the westernmost island of the Canaries, <a href="/wiki/El_Hierro" title="El Hierro">Ferro</a>, 19° 55' west of Paris, as the choice of meridian. Unfortunately, the geographer <a href="/wiki/Guillaume_Delisle" title="Guillaume Delisle">Delisle</a> decided to round this off to 20°, so that it simply became the meridian of Paris disguised.<sup id="cite_ref-5" class="reference"><a href="#cite_note-5">[5]</a></sup></p>
<p>In the early eighteenth century the battle was on to improve the determination of longitude at sea, leading to the development of the <a href="/wiki/Marine_chronometer" title="Marine chronometer">chronometer</a> by <a href="/wiki/John_Harrison" title="John Harrison">John Harrison</a>. But it was the development of accurate star charts principally by the first British <a href="/wiki/Astronomer_Royal" title="Astronomer Royal">Astronomer Royal</a>, <a href="/wiki/John_Flamsteed" title="John Flamsteed">John Flamsteed</a> between 1680 and 1719 and disseminated by his successor, <a href="/wiki/Edmund_Halley" class="mw-redirect" title="Edmund Halley">Edmund Halley</a> that enabled navigators to use the <a href="/wiki/Lunar_distance_(navigation)" title="Lunar distance (navigation)">lunar method</a> of determining longitude more accurately using the <a href="/wiki/Octant_(instrument)" title="Octant (instrument)">octant</a> developed by <a href="/wiki/Thomas_Godfrey_(inventor)" title="Thomas Godfrey (inventor)">Thomas Godfrey</a> and <a href="/wiki/John_Hadley" title="John Hadley">John Hadley</a>.<sup id="cite_ref-6" class="reference"><a href="#cite_note-6">[6]</a></sup> Between 1765 and 1811, <a href="/wiki/Nevil_Maskelyne" title="Nevil Maskelyne">Nevil Maskelyne</a> published 49 issues of the <a href="/wiki/Nautical_Almanac" class="mw-redirect" title="Nautical Almanac">Nautical Almanac</a> based on the meridian of the <a href="/wiki/Royal_Observatory,_Greenwich" title="Royal Observatory, Greenwich">Royal Observatory, Greenwich</a>. "Maskelyne's tables not only made the lunar method practicable, they also made the <a href="/wiki/Prime_meridian_(Greenwich)" title="Prime meridian (Greenwich)">Greenwich meridian</a> the universal reference point. Even the French translations of the <i>Nautical Almanac</i> retained Maskelyne's calculations from Greenwich—in spite of the fact that every other table in the <i><a href="/wiki/Connaissance_des_Temps" title="Connaissance des Temps">Connaissance des Temps</a></i> considered the <a href="/wiki/Paris_meridian" title="Paris meridian">Paris meridian</a> as the prime." <sup id="cite_ref-7" class="reference"><a href="#cite_note-7">[7]</a></sup></p>
<p>In 1884, at the <a href="/wiki/International_Meridian_Conference" title="International Meridian Conference">International Meridian Conference</a> held in <a href="/wiki/Washington,_D.C." title="Washington, D.C.">Washington, D.C.</a>, 22 countries voted to adopt the Greenwich<sup id="cite_ref-8" class="reference"><a href="#cite_note-8">[8]</a></sup> meridian as the prime meridian of the world. The French argued for a neutral line, mentioning the Azores and the <a href="/wiki/Bering_Strait" title="Bering Strait">Bering Strait</a> but eventually abstained and continued to use the Paris meridian until 1911.</p>
<h2><span class="mw-headline" id="List_of_prime_meridians_on_Earth">List of prime meridians on Earth</span><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Prime_meridian&action=edit&section=2" title="Edit section: List of prime meridians on Earth">edit</a><span class="mw-editsection-bracket">]</span></span></h2>
<table class="wikitable">
<tr>
<th>Locality</th>
<th>GPS longitude</th>
<th style="width:200px;">Meridian name</th>
<th>Comment</th>
</tr>
<tr>
<td><a href="/wiki/Bering_Strait" title="Bering Strait">Bering Strait</a></td>
<td>168°30′ W</td>
<td></td>
<td>
<ul>
<li>Bering Strait offered 1884 as possibility for a "neutral prime meridian" by <a href="/wiki/Pierre_Janssen" title="Pierre Janssen">Pierre Janssen</a> at the International Meridian Conference <sup id="cite_ref-9" class="reference"><a href="#cite_note-9">[9]</a></sup></li>
</ul>
</td>
</tr>
<tr>
<td><a href="/wiki/Washington,_D.C." title="Washington, D.C.">Washington, D.C.</a></td>
<td>77°03′56.07″ W (1897) or 77°04′02.24″ W (NAD 27) or 77°04′01.16″ W (NAD 83)</td>
<td><a href="/wiki/New_Naval_Observatory_meridian" class="mw-redirect" title="New Naval Observatory meridian">New Naval Observatory meridian</a></td>
<td></td>
</tr>
<tr>
<td>Washington, D.C.</td>
<td>77°02′48.0″ W, 77°03′02.3″, 77°03′06.119″ W or 77°03′06.276″ W (both presumably NAD 27). If NAD27, the latter would be 77°03′05.194″ W (NAD 83)</td>
<td><a href="/wiki/Old_Naval_Observatory_meridian" class="mw-redirect" title="Old Naval Observatory meridian">Old Naval Observatory meridian</a></td>
<td></td>
</tr>
<tr>
<td>Washington, D.C.</td>
<td>77°02′11.56258″ W (NAD 83), 77°02′11.55880″ W (NAD 83), 77°02′11.57375″ W (NAD 83)</td>
<td><a href="/wiki/White_House_meridian" class="mw-redirect" title="White House meridian">White House meridian</a></td>
<td></td>
</tr>
<tr>
<td>Washington, D.C.</td>
<td>77°00′32.6″ W (NAD 83)</td>
<td><a href="/wiki/Capitol_meridian" class="mw-redirect" title="Capitol meridian">Capitol meridian</a></td>
<td></td>
</tr>
<tr>
<td><a href="/wiki/Philadelphia,_Pennsylvania" class="mw-redirect" title="Philadelphia, Pennsylvania">Philadelphia</a></td>
<td>75° 10′ 12″ W</td>
<td></td>
<td><sup id="cite_ref-Hooker_2006.2C_introduction_10-0" class="reference"><a href="#cite_note-Hooker_2006.2C_introduction-10">[10]</a></sup><sup id="cite_ref-WIRED_11-0" class="reference"><a href="#cite_note-WIRED-11">[11]</a></sup></td>
</tr>
<tr>
<td><a href="/wiki/Rio_de_Janeiro" title="Rio de Janeiro">Rio de Janeiro</a></td>
<td>43° 10′ 19″ W</td>
<td></td>
<td><sup id="cite_ref-12" class="reference"><a href="#cite_note-12">[12]</a></sup></td>
</tr>
<tr>
<td><a href="/wiki/Fortunate_Isles" title="Fortunate Isles">Fortunate Isles</a> / Azores</td>
<td>25° 40′ 32″ W</td>
<td></td>
<td>Used until the Middle Ages, proposed as one possible neutral meridian by <a href="/wiki/Pierre_Janssen" title="Pierre Janssen">Pierre Janssen</a> at the International Meridian Conference<sup id="cite_ref-gutenberg.org_13-0" class="reference"><a href="#cite_note-gutenberg.org-13">[13]</a></sup></td>
</tr>
<tr>
<td><a href="/wiki/El_Hierro" title="El Hierro">El Hierro (Ferro)</a>,<br />
Canary Islands</td>
<td>18° 03′ W,<br />
<span class="nowrap">later redefined as</span><br />
17° 39′ 46″ W</td>
<td><a href="/wiki/Ferro_meridian" class="mw-redirect" title="Ferro meridian">Ferro meridian</a></td>
<td><sup id="cite_ref-14" class="reference"><a href="#cite_note-14">[14]</a></sup></td>
</tr>
<tr>
<td><a href="/wiki/Tenerife" title="Tenerife">Tenerife</a></td>
<td>16° 38' 22" W</td>
<td><a href="/wiki/Tenerife_meridian" title="Tenerife meridian">Tenerife meridian</a></td>
<td>Rose to prominence with Dutch cartographers and navigators after they abandoned the idea of a magnetic meridian<sup id="cite_ref-15" class="reference"><a href="#cite_note-15">[15]</a></sup></td>
</tr>
<tr>
<td><a href="/wiki/Lisbon" title="Lisbon">Lisbon</a></td>
<td>9° 07′ 54.862″ W</td>
<td></td>
<td><sup id="cite_ref-Bartky_16-0" class="reference"><a href="#cite_note-Bartky-16">[16]</a></sup></td>
</tr>
<tr>
<td><a href="/wiki/Madrid" title="Madrid">Madrid</a></td>
<td>3° 41′ 16.58″ W</td>
<td></td>
<td><sup id="cite_ref-Bartky_16-1" class="reference"><a href="#cite_note-Bartky-16">[16]</a></sup></td>
</tr>
<tr>
<td><a href="/wiki/Greenwich" title="Greenwich">Greenwich</a></td>
<td>0° 00′ 05.3101″ W</td>
<td><a href="/wiki/Prime_Meridian_(Greenwich)" class="mw-redirect" title="Prime Meridian (Greenwich)">Greenwich meridian</a></td>
<td>Airy Meridian<sup id="cite_ref-FOOTNOTEDolan2013a_17-0" class="reference"><a href="#cite_note-FOOTNOTEDolan2013a-17">[17]</a></sup></td>
</tr>
<tr>
<td>Greenwich</td>
<td>0° 00′ 05.33″ W</td>
<td><a href="/wiki/United_Kingdom_Ordnance_Survey_Zero_Meridian" title="United Kingdom Ordnance Survey Zero Meridian">United Kingdom Ordnance Survey Zero Meridian</a></td>
<td><a href="/wiki/James_Bradley" title="James Bradley">Bradley</a> Meridian<sup id="cite_ref-FOOTNOTEDolan2013a_17-1" class="reference"><a href="#cite_note-FOOTNOTEDolan2013a-17">[17]</a></sup></td>
</tr>
<tr>
<td>Greenwich</td>
<td>0° 00′ 00.00″</td>
<td><a href="/wiki/IERS_Reference_Meridian" title="IERS Reference Meridian">IERS Reference Meridian</a></td>
<td></td>
</tr>
<tr>
<td><a href="/wiki/Paris" title="Paris">Paris</a></td>
<td>2° 20′ 14.025″ E</td>
<td><a href="/wiki/Paris_meridian" title="Paris meridian">Paris meridian</a></td>
<td></td>
</tr>
<tr>
<td><a href="/wiki/Brussels" title="Brussels">Brussels</a></td>
<td>4° 22′ 4.71″ E</td>
<td></td>
<td><sup id="cite_ref-Bartky_16-2" class="reference"><a href="#cite_note-Bartky-16">[16]</a></sup></td>
</tr>
<tr>
<td><a href="/wiki/Antwerp" title="Antwerp">Antwerp</a></td>
<td>4° 24′ E</td>
<td><a href="/wiki/Antwerp_meridian" class="mw-redirect" title="Antwerp meridian">Antwerp meridian</a></td>
<td><sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (February 2015)">citation needed</span></a></i>]</sup></td>
</tr>
<tr>
<td><a href="/wiki/Amsterdam" title="Amsterdam">Amsterdam</a></td>
<td>4° 53′ E</td>
<td></td>
<td>through the <a href="/wiki/Westerkerk" title="Westerkerk">Westerkerk</a> in Amsterdam; used to define the legal time in the Netherlands from 1909 to 1937<sup id="cite_ref-18" class="reference"><a href="#cite_note-18">[18]</a></sup></td>
</tr>
<tr>
<td><a href="/wiki/Bern" title="Bern">Bern</a></td>
<td>7° 26′ 22.5″ E</td>
<td></td>
<td><sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (July 2013)">citation needed</span></a></i>]</sup></td>
</tr>
<tr>
<td><a href="/wiki/Pisa" title="Pisa">Pisa</a></td>
<td>10° 24′ E</td>
<td></td>
<td><sup id="cite_ref-Hooker_2006.2C_introduction_10-1" class="reference"><a href="#cite_note-Hooker_2006.2C_introduction-10">[10]</a></sup></td>
</tr>
<tr>
<td><a href="/wiki/Oslo" title="Oslo">Oslo (Kristiania)</a></td>
<td>10° 43′ 22.5″ E</td>
<td></td>
<td><sup id="cite_ref-Hooker_2006.2C_introduction_10-2" class="reference"><a href="#cite_note-Hooker_2006.2C_introduction-10">[10]</a></sup><sup id="cite_ref-WIRED_11-1" class="reference"><a href="#cite_note-WIRED-11">[11]</a></sup></td>
</tr>
<tr>
<td><a href="/wiki/Florence" title="Florence">Florence</a></td>
<td>11°15′ E</td>
<td><a href="/wiki/Florence_meridian" title="Florence meridian">Florence meridian</a></td>
<td>used in the <a href="/wiki/Peters_projection" class="mw-redirect" title="Peters projection">Peters projection</a>, <a href="/wiki/Antipodes" title="Antipodes">antipode</a> of a line running through the <a href="/wiki/Bering_Strait" title="Bering Strait">Bering Strait</a></td>
</tr>
<tr>
<td><a href="/wiki/Rome" title="Rome">Rome</a></td>
<td>12° 27′ 08.4″ E</td>
<td><i>meridian of <a href="/wiki/Monte_Mario" title="Monte Mario">Monte Mario</a></i></td>
<td>Used in Roma 40 Datum <sup id="cite_ref-19" class="reference"><a href="#cite_note-19">[19]</a></sup></td>
</tr>
<tr>
<td><a href="/wiki/Copenhagen" title="Copenhagen">Copenhagen</a></td>
<td>12° 34′ 32.25″ E</td>
<td></td>
<td><a href="/wiki/Rundet%C3%A5rn" class="mw-redirect" title="Rundetårn">Rundetårn</a><sup id="cite_ref-20" class="reference"><a href="#cite_note-20">[20]</a></sup></td>
</tr>
<tr>
<td><a href="/wiki/Naples" title="Naples">Naples</a></td>
<td>14° 15′ E</td>
<td></td>
<td><sup id="cite_ref-gutenberg.org_13-1" class="reference"><a href="#cite_note-gutenberg.org-13">[13]</a></sup></td>
</tr>
<tr>
<td><a href="/wiki/Stockholm" title="Stockholm">Stockholm</a></td>
<td>18° 03′ 29.8″ E</td>
<td></td>
<td>at the <a href="/wiki/Stockholm_Observatory" title="Stockholm Observatory">Stockholm Observatory</a><sup id="cite_ref-Bartky_16-3" class="reference"><a href="#cite_note-Bartky-16">[16]</a></sup></td>
</tr>
<tr>
<td><a href="/wiki/Krakow" class="mw-redirect" title="Krakow">Krakow</a></td>
<td>19° 57′ 21.43″ E</td>
<td><a href="/w/index.php?title=Krakow_meridian&action=edit&redlink=1" class="new" title="Krakow meridian (page does not exist)">Krakow meridian</a></td>
<td>at the Old Krakow Observatory at the <a href="/wiki/Botanic_Garden_of_the_Jagiellonian_University" title="Botanic Garden of the Jagiellonian University">Śniadecki' College</a> mentioned also in Nikolas Copernicus' work "On the Revolutions of the Heavenly Spheres".</td>
</tr>
<tr>
<td><a href="/wiki/Warsaw" title="Warsaw">Warsaw</a></td>
<td>21° 00′ 42″ E</td>
<td><a href="/wiki/Warsaw_meridian" title="Warsaw meridian">Warsaw meridian</a></td>
<td><sup id="cite_ref-Bartky_16-4" class="reference"><a href="#cite_note-Bartky-16">[16]</a></sup></td>
</tr>
<tr>
<td><a href="/wiki/Oradea" title="Oradea">Oradea</a></td>
<td>21° 55′ 16″ E</td>
<td></td>
<td><sup id="cite_ref-21" class="reference"><a href="#cite_note-21">[21]</a></sup></td>
</tr>
<tr>
<td><a href="/wiki/Alexandria" title="Alexandria">Alexandria</a></td>
<td>29° 53′ E</td>
<td></td>
<td><sup id="cite_ref-22" class="reference"><a href="#cite_note-22">[22]</a></sup></td>
</tr>
<tr>
<td><a href="/wiki/Saint_Petersburg" title="Saint Petersburg">Saint Petersburg</a></td>
<td>30° 19′ 42.09″ E</td>
<td><a href="/wiki/Pulkovo_meridian" title="Pulkovo meridian">Pulkovo meridian</a></td>
<td></td>
</tr>
<tr>
<td><span class="nowrap"><a href="/wiki/Great_Pyramid_of_Giza" title="Great Pyramid of Giza">Great Pyramid of Giza</a></span></td>
<td>31° 08′ 03.69″ E</td>
<td></td>
<td>1884 <sup id="cite_ref-23" class="reference"><a href="#cite_note-23">[23]</a></sup></td>
</tr>
<tr>
<td><a href="/wiki/Jerusalem" title="Jerusalem">Jerusalem</a></td>
<td>35° 13′ 47.1″ E</td>
<td></td>
<td><sup id="cite_ref-WIRED_11-2" class="reference"><a href="#cite_note-WIRED-11">[11]</a></sup></td>
</tr>
<tr>
<td><a href="/wiki/Mecca" title="Mecca">Mecca</a></td>
<td>39° 49′ 34″ E</td>
<td></td>
<td>see also <a href="/wiki/Mecca_Time" title="Mecca Time">Mecca Time</a> <sup id="cite_ref-24" class="reference"><a href="#cite_note-24">[24]</a></sup></td>
</tr>
<tr>
<td><a href="/wiki/Ujjain" title="Ujjain">Ujjain</a></td>
<td>75° 47′ E</td>
<td></td>
<td>Used from 4th century CE Indian astronomy and calendars(see also <a href="/wiki/Time_in_India#Ancient_India" title="Time in India">Time in India</a>).<sup id="cite_ref-25" class="reference"><a href="#cite_note-25">[25]</a></sup></td>
</tr>
<tr>
<td><a href="/wiki/Kyoto" title="Kyoto">Kyoto</a></td>
<td>136° 14′ E</td>
<td></td>
<td>Used in 18th and 19th (officially 1779–1871) century Japanese maps. Exact place unknown, but in "Kairekisyo" in Nishigekkoutyou-town in Kyoto, then the capital.<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (July 2013)">citation needed</span></a></i>]</sup></td>
</tr>
<tr>
<td></td>
<td>~ 180</td>
<td></td>
<td>Opposite of Greenwich, proposed 13 October 1884 on the International Meridian Conference by <a href="/wiki/Sandford_Fleming" title="Sandford Fleming">Sandford Fleming</a> <sup id="cite_ref-gutenberg.org_13-2" class="reference"><a href="#cite_note-gutenberg.org-13">[13]</a></sup></td>
</tr>
</table>
<h2><span class="mw-headline" id="International_prime_meridian">International prime meridian</span><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Prime_meridian&action=edit&section=3" title="Edit section: International prime meridian">edit</a><span class="mw-editsection-bracket">]</span></span></h2>
<p>In October 1884 the <a href="/wiki/Prime_meridian_(Greenwich)" title="Prime meridian (Greenwich)">Greenwich Meridian</a> was selected by delegates (forty-one delegates representing twenty-five nations) to the <a href="/wiki/International_Meridian_Conference" title="International Meridian Conference">International Meridian Conference</a> held in <a href="/wiki/Washington,_D.C." title="Washington, D.C.">Washington, D.C.</a>, <a href="/wiki/United_States" title="United States">United States</a> to be the common zero of longitude and standard of time reckoning throughout the world.<sup id="cite_ref-imc_26-0" class="reference"><a href="#cite_note-imc-26">[26]</a></sup><sup id="cite_ref-note1884_28-0" class="reference"><a href="#cite_note-note1884-28">[note 1]</a></sup> The modern prime meridian, the IERS Reference Meridian, is placed very near this meridian and is the prime meridian that currently has the widest use.</p>
<h3><span class="mw-headline" id="Prime_meridian_at_Greenwich">Prime meridian at Greenwich<span id="Greenwich"></span></span><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Prime_meridian&action=edit&section=4" title="Edit section: Prime meridian at Greenwich">edit</a><span class="mw-editsection-bracket">]</span></span></h3>
<div class="thumb tright">
<div class="thumbinner" style="width:182px;"><a href="/wiki/File:Prime_meridian.jpg" class="image"><img alt="" src="//upload.wikimedia.org/wikipedia/commons/thumb/d/d5/Prime_meridian.jpg/180px-Prime_meridian.jpg" width="180" height="240" class="thumbimage" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/d/d5/Prime_meridian.jpg/270px-Prime_meridian.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/d/d5/Prime_meridian.jpg/360px-Prime_meridian.jpg 2x" data-file-width="450" data-file-height="600" /></a>
<div class="thumbcaption">
<div class="magnify"><a href="/wiki/File:Prime_meridian.jpg" class="internal" title="Enlarge"></a></div>
Markings of the prime meridian at the Royal Observatory, Greenwich.</div>
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</div>
<div role="note" class="hatnote">Main article: <a href="/wiki/Prime_Meridian_(Greenwich)" class="mw-redirect" title="Prime Meridian (Greenwich)">Prime Meridian (Greenwich)</a></div>
<p>The modern prime meridian, based at the <a href="/wiki/Royal_Observatory,_Greenwich" title="Royal Observatory, Greenwich">Royal Observatory, Greenwich</a>, was established by <a href="/wiki/George_Biddell_Airy" title="George Biddell Airy">Sir George Airy</a> in 1851.<sup id="cite_ref-Greenwich_Observatory_p.10_29-0" class="reference"><a href="#cite_note-Greenwich_Observatory_p.10-29">[28]</a></sup></p>
<p>The position of the Greenwich Meridian has been defined by the location of the Airy <a href="/wiki/Transit_Circle" class="mw-redirect" title="Transit Circle">Transit Circle</a> ever since the first observation was taken with it by <a href="/wiki/George_Biddell_Airy" title="George Biddell Airy">Sir George Airy</a> in 1851.<sup id="cite_ref-Greenwich_Observatory_p.10_29-1" class="reference"><a href="#cite_note-Greenwich_Observatory_p.10-29">[28]</a></sup> Prior to that, it was defined by a succession of earlier transit instruments, the first of which was acquired by the second <a href="/wiki/Astronomer_Royal" title="Astronomer Royal">Astronomer Royal</a>, <a href="/wiki/Edmond_Halley" title="Edmond Halley">Edmond Halley</a> in 1721. It was set up in the extreme north-west corner of the Observatory between Flamsteed House and the Western Summer House. This spot, now subsumed into Flamsteed House, is roughly 43 metres to the west of the Airy Transit Circle, a distance equivalent to roughly 0.15 seconds of time.<sup id="cite_ref-FOOTNOTEDolan2013a_17-2" class="reference"><a href="#cite_note-FOOTNOTEDolan2013a-17">[17]</a></sup> It was Airy's transit circle that was adopted in principle (with French delegates, who pressed for adoption of the <a href="/wiki/Paris_meridian" title="Paris meridian">Paris meridian</a> abstaining) as the Prime Meridian of the world at the 1884 International Meridian Conference.<sup id="cite_ref-Time_30-0" class="reference"><a href="#cite_note-Time-30">[29]</a></sup><sup id="cite_ref-RMG_31-0" class="reference"><a href="#cite_note-RMG-31">[30]</a></sup></p>
<p>All of these Greenwich meridians were located via an astronomic observation from the surface of the Earth, oriented via a <a href="/wiki/Plumb_line" class="mw-redirect" title="Plumb line">plumb line</a> along the direction of gravity at the surface. This astronomic Greenwich meridian was disseminated around the world, first via the <a href="/wiki/Lunar_distance_method" class="mw-redirect" title="Lunar distance method">lunar distance method</a>, then by chronometers carried on ships, then via telegraph lines carried by <a href="/wiki/Submarine_communications_cable" title="Submarine communications cable">submarine communications cables</a>, then via radio time signals. One remote longitude ultimately based on the Greenwich meridian using these methods was that of the <a href="/wiki/North_American_Datum#North_American_Datum_of_1927" title="North American Datum">North American Datum 1927</a> or NAD27, an ellipsoid whose surface best matches <a href="/wiki/Mean_sea_level" class="mw-redirect" title="Mean sea level">mean sea level</a> under the <a href="/wiki/United_States" title="United States">United States</a>.</p>
<h3><span class="mw-headline" id="IERS_Reference_Meridian">IERS Reference Meridian</span><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Prime_meridian&action=edit&section=5" title="Edit section: IERS Reference Meridian">edit</a><span class="mw-editsection-bracket">]</span></span></h3>
<div role="note" class="hatnote">Main article: <a href="/wiki/IERS_Reference_Meridian" title="IERS Reference Meridian">IERS Reference Meridian</a></div>
<p>Satellites changed the reference from the surface of the Earth to its centre of mass around which all satellites orbit regardless of surface irregularities. The requirement that satellite-based geodetic reference systems be centred on the centre of mass of the earth caused the modern prime meridian to be 5.3" east of the astronomic Greenwich prime meridian through the Airy Transit Circle. At the latitude of Greenwich, this amounts to 102 metres.<sup id="cite_ref-32" class="reference"><a href="#cite_note-32">[31]</a></sup> This was officially accepted by the <a href="/wiki/Bureau_International_de_l%27Heure" class="mw-redirect" title="Bureau International de l'Heure">Bureau International de l'Heure</a> (BIH) in 1984 via its BTS84 (BIH Terrestrial System) that later became WGS84 (World Geodetic System 1984) and the various ITRFs (International Terrestrial Reference Systems).</p>
<p>Due to the movement of Earth's <a href="/wiki/Plate_tectonics" title="Plate tectonics">tectonic plates</a>, the line of 0° longitude along the surface of the Earth has slowly moved toward the west from this shifted position by a few centimetres; that is, towards the Airy Transit Circle (or the Airy Transit Circle has moved toward the east, depending on your point of view) since 1984 (or the 1960s). With the introduction of satellite technology, it became possible to create a more accurate and detailed global map. With these advances there also arose the necessity to define a reference meridian that, whilst being derived from the Airy Transit Circle, would also take into account the effects of plate movement and variations in the way that the Earth was spinning.<sup id="cite_ref-FOOTNOTEDolan2013b_33-0" class="reference"><a href="#cite_note-FOOTNOTEDolan2013b-33">[32]</a></sup> As a result, the <a href="/wiki/IERS_Reference_Meridian" title="IERS Reference Meridian">International Reference Meridian</a> was established and is commonly used to <a href="/wiki/Denotation_(semiotics)" title="Denotation (semiotics)">denote</a> Earth's prime meridian (0° longitude) by the <a href="/wiki/International_Earth_Rotation_and_Reference_Systems_Service" title="International Earth Rotation and Reference Systems Service">International Earth Rotation and Reference Systems Service</a>, which defines and maintains the link between longitude and time. Based on observations to satellites and celestial compact radio sources (quasars) from various coordinated stations around the globe, Airy's <a href="/wiki/Transit_circle" class="mw-redirect" title="Transit circle">transit circle</a> drifts northeast about 2.5 centimetres per year relative to this Earth-centred 0° longitude. Circa 1999 the <b>international reference meridian</b> (IRM) passed 5.31 <a href="/wiki/Arcsecond" class="mw-redirect" title="Arcsecond">arcseconds</a> east of Airy's meridian or 102.5 metres (336.3 feet) at the <a href="/wiki/Latitude" title="Latitude">latitude</a> of the Royal Observatory, Greenwich, London.<sup id="cite_ref-GPS_34-0" class="reference"><a href="#cite_note-GPS-34">[33]</a></sup><sup id="cite_ref-IRM_35-0" class="reference"><a href="#cite_note-IRM-35">[34]</a></sup><sup id="cite_ref-Observatory_36-0" class="reference"><a href="#cite_note-Observatory-36">[35]</a></sup><sup id="cite_ref-37" class="reference"><a href="#cite_note-37">[36]</a></sup> It is also the reference meridian of the <a href="/wiki/Global_Positioning_System" title="Global Positioning System">Global Positioning System</a> operated by the <a href="/wiki/United_States_Department_of_Defense" title="United States Department of Defense">United States Department of Defense</a>, and of <a href="/wiki/WGS84" class="mw-redirect" title="WGS84">WGS84</a> and its two formal versions, the ideal <a href="/wiki/International_Terrestrial_Reference_System" title="International Terrestrial Reference System">International Terrestrial Reference System</a> (ITRS) and its realization, the <a href="/wiki/International_Terrestrial_Reference_Frame" class="mw-redirect" title="International Terrestrial Reference Frame">International Terrestrial Reference Frame</a> (ITRF).<sup id="cite_ref-GPS_34-1" class="reference"><a href="#cite_note-GPS-34">[33]</a></sup><sup id="cite_ref-IRM_35-1" class="reference"><a href="#cite_note-IRM-35">[34]</a></sup><sup id="cite_ref-Observatory_36-1" class="reference"><a href="#cite_note-Observatory-36">[35]</a></sup> A current convention on the Earth uses the opposite of the <b>IRM</b> as the basis for the <a href="/wiki/International_Date_Line" title="International Date Line">International Date Line</a>.</p>
<h4><span class="mw-headline" id="List_of_places">List of places</span><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Prime_meridian&action=edit&section=6" title="Edit section: List of places">edit</a><span class="mw-editsection-bracket">]</span></span></h4>
<table class="collapsible collapsed noprint infobox" id="GeoGroup" style="width: 23em; font-size: 88%; line-height: 1.5em">
<tr>
<th style="text-align:left;"><a class="external text" href="//tools.wmflabs.org/osm4wiki/cgi-bin/wiki/wiki-osm.pl?project=en&article=Prime_meridian">Map all coordinates using OSM</a><br />
<a class="external text" href="//tools.wmflabs.org/wp-world/googlmaps-proxy.php?page=https:%2F%2Ftools.wmflabs.org%2Fkmlexport%3Farticle%3DPrime_meridian&output=classic">Map all coordinates using Google</a><br />
<a class="external text" href="//tools.wmflabs.org/kmlexport?article=Prime_meridian&redir=bing">Map up to 200 coordinates using Bing</a></th>
</tr>
<tr>
<td><a class="external text" href="//tools.wmflabs.org/kmlexport?article=Prime_meridian">Export all coordinates</a> as <a href="/wiki/Keyhole_Markup_Language" title="Keyhole Markup Language">KML</a></td>
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<tr>
<td><a rel="nofollow" class="external text" href="http://maps.bing.com/GeoCommunity.asjx?action=retrieverss&mkt=en&mapurl=http%3A%2F%2Ftools.wmflabs.org%2Fkmlexport%3Farticle%3DPrime_meridian">Export all coordinates</a> as <a href="/wiki/GeoRSS" title="GeoRSS">GeoRSS</a></td>
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<tr>
<td><a rel="nofollow" class="external text" href="http://tripgang.com/kml2gpx/http%3A%2F%2Ftools.wmflabs.org%2Fkmlexport%3Farticle%3DPrime_meridian?gpx=1">Export all coordinates</a> as <a href="/wiki/GPS_eXchange_Format" class="mw-redirect" title="GPS eXchange Format">GPX</a></td>
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<tr>
<td><a rel="nofollow" class="external text" href="http://maps.google.com/maps?q=http%3A%2F%2Fmicroform.at%2Fgeo%2Fhttp%3A%2F%2Fen.wikipedia.org%2Fwiki%2FPrime_meridian">Map all microformatted coordinates</a></td>
</tr>
<tr>
<td><a rel="nofollow" class="external text" href="http://microform.at/?type=hcard-rdf&url=http://en.wikipedia.org/wiki/Prime_meridian">Place data as RDF</a></td>
</tr>
</table>
<p>On Earth, starting at the <a href="/wiki/North_Pole" title="North Pole">North Pole</a> and heading south to the <a href="/wiki/South_Pole" title="South Pole">South Pole</a>, the IERS Reference Meridian (as of 2016) passes through:</p>
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<dd>
<table class="wikitable plainrowheaders">
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<th scope="col" width="125">Co-ordinates<br />
(approximate)</th>
<th scope="col">Country, territory or sea</th>
<th scope="col">Notes</th>
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<td style="background:#b0e0e6;"><span class="plainlinks nourlexpansion"><a class="external text" href="//tools.wmflabs.org/geohack/geohack.php?pagename=Prime_meridian&params=90_0_N_0_0_E_type:waterbody&title=North+Pole"><span class="geo-default"><span class="geo-dms" title="Maps, aerial photos, and other data for this location"><span class="latitude">90°0′N</span> <span class="longitude">0°0′E</span></span></span><span class="geo-multi-punct"> / </span><span class="geo-nondefault"><span class="vcard"><span class="geo-dec" title="Maps, aerial photos, and other data for this location">90.000°N 0.000°E</span><span style="display:none"> / <span class="geo">90.000; 0.000</span></span><span style="display:none"> (<span class="fn org">North Pole</span>)</span></span></span></a></span></td>
<th scope="row" style="background:#b0e0e6;"><a href="/wiki/Arctic_Ocean" title="Arctic Ocean">Arctic Ocean</a></th>
<td style="background:#b0e0e6;"></td>
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<td style="background:#b0e0e6;"><span class="plainlinks nourlexpansion"><a class="external text" href="//tools.wmflabs.org/geohack/geohack.php?pagename=Prime_meridian&params=81_39_N_0_0_E_type:waterbody&title=Greenland+Sea"><span class="geo-default"><span class="geo-dms" title="Maps, aerial photos, and other data for this location"><span class="latitude">81°39′N</span> <span class="longitude">0°0′E</span></span></span><span class="geo-multi-punct"> / </span><span class="geo-nondefault"><span class="vcard"><span class="geo-dec" title="Maps, aerial photos, and other data for this location">81.650°N 0.000°E</span><span style="display:none"> / <span class="geo">81.650; 0.000</span></span><span style="display:none"> (<span class="fn org">Greenland Sea</span>)</span></span></span></a></span></td>
<th scope="row" style="background:#b0e0e6;"><a href="/wiki/Greenland_Sea" title="Greenland Sea">Greenland Sea</a></th>
<td style="background:#b0e0e6;"></td>
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<td style="background:#b0e0e6;"><span class="plainlinks nourlexpansion"><a class="external text" href="//tools.wmflabs.org/geohack/geohack.php?pagename=Prime_meridian&params=72_53_N_0_0_E_type:waterbody&title=Norwegian+Sea"><span class="geo-default"><span class="geo-dms" title="Maps, aerial photos, and other data for this location"><span class="latitude">72°53′N</span> <span class="longitude">0°0′E</span></span></span><span class="geo-multi-punct"> / </span><span class="geo-nondefault"><span class="vcard"><span class="geo-dec" title="Maps, aerial photos, and other data for this location">72.883°N 0.000°E</span><span style="display:none"> / <span class="geo">72.883; 0.000</span></span><span style="display:none"> (<span class="fn org">Norwegian Sea</span>)</span></span></span></a></span></td>
<th scope="row" style="background:#b0e0e6;"><a href="/wiki/Norwegian_Sea" title="Norwegian Sea">Norwegian Sea</a></th>
<td style="background:#b0e0e6;"></td>
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<td style="background:#b0e0e6;"><span class="plainlinks nourlexpansion"><a class="external text" href="//tools.wmflabs.org/geohack/geohack.php?pagename=Prime_meridian&params=61_0_N_0_0_E_type:waterbody&title=North+Sea"><span class="geo-default"><span class="geo-dms" title="Maps, aerial photos, and other data for this location"><span class="latitude">61°0′N</span> <span class="longitude">0°0′E</span></span></span><span class="geo-multi-punct"> / </span><span class="geo-nondefault"><span class="vcard"><span class="geo-dec" title="Maps, aerial photos, and other data for this location">61.000°N 0.000°E</span><span style="display:none"> / <span class="geo">61.000; 0.000</span></span><span style="display:none"> (<span class="fn org">North Sea</span>)</span></span></span></a></span></td>
<th scope="row" style="background:#b0e0e6;"><a href="/wiki/North_Sea" title="North Sea">North Sea</a></th>
<td style="background:#b0e0e6;"></td>
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<tr style="vertical-align:top;">
<td><span class="plainlinks nourlexpansion"><a class="external text" href="//tools.wmflabs.org/geohack/geohack.php?pagename=Prime_meridian&params=53_45_N_0_0_E_type:country&title=United+Kingdom"><span class="geo-default"><span class="geo-dms" title="Maps, aerial photos, and other data for this location"><span class="latitude">53°45′N</span> <span class="longitude">0°0′E</span></span></span><span class="geo-multi-punct"> / </span><span class="geo-nondefault"><span class="vcard"><span class="geo-dec" title="Maps, aerial photos, and other data for this location">53.750°N 0.000°E</span><span style="display:none"> / <span class="geo">53.750; 0.000</span></span><span style="display:none"> (<span class="fn org">United Kingdom</span>)</span></span></span></a></span></td>
<th scope="row"><span class="flagicon"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/a/ae/Flag_of_the_United_Kingdom.svg/23px-Flag_of_the_United_Kingdom.svg.png" width="23" height="12" class="thumbborder" srcset="//upload.wikimedia.org/wikipedia/en/thumb/a/ae/Flag_of_the_United_Kingdom.svg/35px-Flag_of_the_United_Kingdom.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/a/ae/Flag_of_the_United_Kingdom.svg/46px-Flag_of_the_United_Kingdom.svg.png 2x" data-file-width="1200" data-file-height="600" /> </span><a href="/wiki/United_Kingdom" title="United Kingdom">United Kingdom</a></th>
<td>From <a href="/wiki/Tunstall,_East_Riding_of_Yorkshire" title="Tunstall, East Riding of Yorkshire">Tunstall in East Riding</a> to <a href="/wiki/Peacehaven" title="Peacehaven">Peacehaven</a>, passing through <a href="/wiki/Greenwich" title="Greenwich">Greenwich</a></td>
</tr>
<tr>
<td style="background:#b0e0e6;"><span class="plainlinks nourlexpansion"><a class="external text" href="//tools.wmflabs.org/geohack/geohack.php?pagename=Prime_meridian&params=50_47_N_0_0_E_type:waterbody&title=English+Channel"><span class="geo-default"><span class="geo-dms" title="Maps, aerial photos, and other data for this location"><span class="latitude">50°47′N</span> <span class="longitude">0°0′E</span></span></span><span class="geo-multi-punct"> / </span><span class="geo-nondefault"><span class="vcard"><span class="geo-dec" title="Maps, aerial photos, and other data for this location">50.783°N 0.000°E</span><span style="display:none"> / <span class="geo">50.783; 0.000</span></span><span style="display:none"> (<span class="fn org">English Channel</span>)</span></span></span></a></span></td>
<th scope="row" style="background:#b0e0e6;"><a href="/wiki/English_Channel" title="English Channel">English Channel</a></th>
<td style="background:#b0e0e6;"></td>
</tr>
<tr style="vertical-align:top;">
<td><span class="plainlinks nourlexpansion"><a class="external text" href="//tools.wmflabs.org/geohack/geohack.php?pagename=Prime_meridian&params=49_19_N_0_0_E_type:country&title=France"><span class="geo-default"><span class="geo-dms" title="Maps, aerial photos, and other data for this location"><span class="latitude">49°19′N</span> <span class="longitude">0°0′E</span></span></span><span class="geo-multi-punct"> / </span><span class="geo-nondefault"><span class="vcard"><span class="geo-dec" title="Maps, aerial photos, and other data for this location">49.317°N 0.000°E</span><span style="display:none"> / <span class="geo">49.317; 0.000</span></span><span style="display:none"> (<span class="fn org">France</span>)</span></span></span></a></span></td>
<th scope="row"><span class="flagicon"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/c/c3/Flag_of_France.svg/23px-Flag_of_France.svg.png" width="23" height="15" class="thumbborder" srcset="//upload.wikimedia.org/wikipedia/en/thumb/c/c3/Flag_of_France.svg/35px-Flag_of_France.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/c/c3/Flag_of_France.svg/45px-Flag_of_France.svg.png 2x" data-file-width="900" data-file-height="600" /> </span><a href="/wiki/France" title="France">France</a></th>
<td>From <a href="/wiki/Villers-sur-Mer" title="Villers-sur-Mer">Villers-sur-Mer</a> to <a href="/wiki/Gavarnie" title="Gavarnie">Gavarnie</a></td>
</tr>
<tr>
<td><span class="plainlinks nourlexpansion"><a class="external text" href="//tools.wmflabs.org/geohack/geohack.php?pagename=Prime_meridian&params=42_41_N_0_0_E_type:country&title=Spain"><span class="geo-default"><span class="geo-dms" title="Maps, aerial photos, and other data for this location"><span class="latitude">42°41′N</span> <span class="longitude">0°0′E</span></span></span><span class="geo-multi-punct"> / </span><span class="geo-nondefault"><span class="vcard"><span class="geo-dec" title="Maps, aerial photos, and other data for this location">42.683°N 0.000°E</span><span style="display:none"> / <span class="geo">42.683; 0.000</span></span><span style="display:none"> (<span class="fn org">Spain</span>)</span></span></span></a></span></td>
<th scope="row"><span class="flagicon"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/9/9a/Flag_of_Spain.svg/23px-Flag_of_Spain.svg.png" width="23" height="15" class="thumbborder" srcset="//upload.wikimedia.org/wikipedia/en/thumb/9/9a/Flag_of_Spain.svg/35px-Flag_of_Spain.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/9/9a/Flag_of_Spain.svg/45px-Flag_of_Spain.svg.png 2x" data-file-width="750" data-file-height="500" /> </span><a href="/wiki/Spain" title="Spain">Spain</a></th>
<td>From <a href="/wiki/Cilindro_de_Marbor%C3%A9" title="Cilindro de Marboré">Cilindro de Marboré</a> to <a href="/wiki/Castell%C3%B3n_de_la_Plana" title="Castellón de la Plana">Castellón de la Plana</a></td>
</tr>
<tr>
<td style="background:#b0e0e6;"><span class="plainlinks nourlexpansion"><a class="external text" href="//tools.wmflabs.org/geohack/geohack.php?pagename=Prime_meridian&params=39_56_N_0_0_E_type:waterbody&title=Mediterranean+Sea"><span class="geo-default"><span class="geo-dms" title="Maps, aerial photos, and other data for this location"><span class="latitude">39°56′N</span> <span class="longitude">0°0′E</span></span></span><span class="geo-multi-punct"> / </span><span class="geo-nondefault"><span class="vcard"><span class="geo-dec" title="Maps, aerial photos, and other data for this location">39.933°N 0.000°E</span><span style="display:none"> / <span class="geo">39.933; 0.000</span></span><span style="display:none"> (<span class="fn org">Mediterranean Sea</span>)</span></span></span></a></span></td>
<th scope="row" style="background:#b0e0e6;"><a href="/wiki/Mediterranean_Sea" title="Mediterranean Sea">Mediterranean Sea</a></th>
<td style="background:#b0e0e6;"><a href="/wiki/Gulf_of_Valencia" title="Gulf of Valencia">Gulf of Valencia</a></td>
</tr>
<tr>
<td><span class="plainlinks nourlexpansion"><a class="external text" href="//tools.wmflabs.org/geohack/geohack.php?pagename=Prime_meridian&params=38_52_N_0_0_E_type:country&title=Spain"><span class="geo-default"><span class="geo-dms" title="Maps, aerial photos, and other data for this location"><span class="latitude">38°52′N</span> <span class="longitude">0°0′E</span></span></span><span class="geo-multi-punct"> / </span><span class="geo-nondefault"><span class="vcard"><span class="geo-dec" title="Maps, aerial photos, and other data for this location">38.867°N 0.000°E</span><span style="display:none"> / <span class="geo">38.867; 0.000</span></span><span style="display:none"> (<span class="fn org">Spain</span>)</span></span></span></a></span></td>
<th scope="row"><span class="flagicon"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/9/9a/Flag_of_Spain.svg/23px-Flag_of_Spain.svg.png" width="23" height="15" class="thumbborder" srcset="//upload.wikimedia.org/wikipedia/en/thumb/9/9a/Flag_of_Spain.svg/35px-Flag_of_Spain.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/9/9a/Flag_of_Spain.svg/45px-Flag_of_Spain.svg.png 2x" data-file-width="750" data-file-height="500" /> </span><a href="/wiki/Spain" title="Spain">Spain</a></th>
<td>From <a href="/wiki/El_Verger" title="El Verger">El Verger</a> to <a href="/wiki/Calpe" class="mw-redirect" title="Calpe">Calpe</a></td>
</tr>
<tr>
<td style="background:#b0e0e6;"><span class="plainlinks nourlexpansion"><a class="external text" href="//tools.wmflabs.org/geohack/geohack.php?pagename=Prime_meridian&params=38_38_N_0_0_E_type:waterbody&title=Mediterranean+Sea"><span class="geo-default"><span class="geo-dms" title="Maps, aerial photos, and other data for this location"><span class="latitude">38°38′N</span> <span class="longitude">0°0′E</span></span></span><span class="geo-multi-punct"> / </span><span class="geo-nondefault"><span class="vcard"><span class="geo-dec" title="Maps, aerial photos, and other data for this location">38.633°N 0.000°E</span><span style="display:none"> / <span class="geo">38.633; 0.000</span></span><span style="display:none"> (<span class="fn org">Mediterranean Sea</span>)</span></span></span></a></span></td>
<th scope="row" style="background:#b0e0e6;"><a href="/wiki/Mediterranean_Sea" title="Mediterranean Sea">Mediterranean Sea</a></th>
<td style="background:#b0e0e6;"></td>
</tr>
<tr>
<td><span class="plainlinks nourlexpansion"><a class="external text" href="//tools.wmflabs.org/geohack/geohack.php?pagename=Prime_meridian&params=35_50_N_0_0_E_type:country&title=Algeria"><span class="geo-default"><span class="geo-dms" title="Maps, aerial photos, and other data for this location"><span class="latitude">35°50′N</span> <span class="longitude">0°0′E</span></span></span><span class="geo-multi-punct"> / </span><span class="geo-nondefault"><span class="vcard"><span class="geo-dec" title="Maps, aerial photos, and other data for this location">35.833°N 0.000°E</span><span style="display:none"> / <span class="geo">35.833; 0.000</span></span><span style="display:none"> (<span class="fn org">Algeria</span>)</span></span></span></a></span></td>
<th scope="row"><span class="flagicon"><img alt="" src="//upload.wikimedia.org/wikipedia/commons/thumb/7/77/Flag_of_Algeria.svg/23px-Flag_of_Algeria.svg.png" width="23" height="15" class="thumbborder" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/7/77/Flag_of_Algeria.svg/35px-Flag_of_Algeria.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/7/77/Flag_of_Algeria.svg/45px-Flag_of_Algeria.svg.png 2x" data-file-width="900" data-file-height="600" /> </span><a href="/wiki/Algeria" title="Algeria">Algeria</a></th>
<td>From <a href="/wiki/Stidia" title="Stidia">Stidia</a> to Algeria-Mali border near <a href="/wiki/Bordj_Mokhtar" class="mw-redirect" title="Bordj Mokhtar">Bordj Mokhtar</a></td>
</tr>
<tr>
<td><span class="plainlinks nourlexpansion"><a class="external text" href="//tools.wmflabs.org/geohack/geohack.php?pagename=Prime_meridian&params=21_50_N_0_0_E_type:country&title=Mali"><span class="geo-default"><span class="geo-dms" title="Maps, aerial photos, and other data for this location"><span class="latitude">21°50′N</span> <span class="longitude">0°0′E</span></span></span><span class="geo-multi-punct"> / </span><span class="geo-nondefault"><span class="vcard"><span class="geo-dec" title="Maps, aerial photos, and other data for this location">21.833°N 0.000°E</span><span style="display:none"> / <span class="geo">21.833; 0.000</span></span><span style="display:none"> (<span class="fn org">Mali</span>)</span></span></span></a></span></td>
<th scope="row"><span class="flagicon"><img alt="" src="//upload.wikimedia.org/wikipedia/commons/thumb/9/92/Flag_of_Mali.svg/23px-Flag_of_Mali.svg.png" width="23" height="15" class="thumbborder" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/9/92/Flag_of_Mali.svg/35px-Flag_of_Mali.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/9/92/Flag_of_Mali.svg/45px-Flag_of_Mali.svg.png 2x" data-file-width="450" data-file-height="300" /> </span><a href="/wiki/Mali" title="Mali">Mali</a></th>
<td></td>
</tr>
<tr>
<td><span class="plainlinks nourlexpansion"><a class="external text" href="//tools.wmflabs.org/geohack/geohack.php?pagename=Prime_meridian&params=14_59_N_0_0_E_type:country&title=Burkina+Faso"><span class="geo-default"><span class="geo-dms" title="Maps, aerial photos, and other data for this location"><span class="latitude">14°59′N</span> <span class="longitude">0°0′E</span></span></span><span class="geo-multi-punct"> / </span><span class="geo-nondefault"><span class="vcard"><span class="geo-dec" title="Maps, aerial photos, and other data for this location">14.983°N 0.000°E</span><span style="display:none"> / <span class="geo">14.983; 0.000</span></span><span style="display:none"> (<span class="fn org">Burkina Faso</span>)</span></span></span></a></span></td>
<th scope="row"><span class="flagicon"><img alt="" src="//upload.wikimedia.org/wikipedia/commons/thumb/3/31/Flag_of_Burkina_Faso.svg/23px-Flag_of_Burkina_Faso.svg.png" width="23" height="15" class="thumbborder" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/3/31/Flag_of_Burkina_Faso.svg/35px-Flag_of_Burkina_Faso.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/3/31/Flag_of_Burkina_Faso.svg/45px-Flag_of_Burkina_Faso.svg.png 2x" data-file-width="900" data-file-height="600" /> </span><a href="/wiki/Burkina_Faso" title="Burkina Faso">Burkina Faso</a></th>
<td></td>
</tr>
<tr>
<td><span class="plainlinks nourlexpansion"><a class="external text" href="//tools.wmflabs.org/geohack/geohack.php?pagename=Prime_meridian&params=11_6_N_0_0_E_type:country&title=Togo"><span class="geo-default"><span class="geo-dms" title="Maps, aerial photos, and other data for this location"><span class="latitude">11°6′N</span> <span class="longitude">0°0′E</span></span></span><span class="geo-multi-punct"> / </span><span class="geo-nondefault"><span class="vcard"><span class="geo-dec" title="Maps, aerial photos, and other data for this location">11.100°N 0.000°E</span><span style="display:none"> / <span class="geo">11.100; 0.000</span></span><span style="display:none"> (<span class="fn org">Togo</span>)</span></span></span></a></span></td>
<th scope="row"><span class="flagicon"><img alt="" src="//upload.wikimedia.org/wikipedia/commons/thumb/6/68/Flag_of_Togo.svg/23px-Flag_of_Togo.svg.png" width="23" height="14" class="thumbborder" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/6/68/Flag_of_Togo.svg/35px-Flag_of_Togo.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/6/68/Flag_of_Togo.svg/46px-Flag_of_Togo.svg.png 2x" data-file-width="809" data-file-height="500" /> </span><a href="/wiki/Togo" title="Togo">Togo</a></th>
<td>For about 600 m</td>
</tr>
<tr>
<td><span class="plainlinks nourlexpansion"><a class="external text" href="//tools.wmflabs.org/geohack/geohack.php?pagename=Prime_meridian&params=11_6_N_0_0_E_type:country&title=Ghana"><span class="geo-default"><span class="geo-dms" title="Maps, aerial photos, and other data for this location"><span class="latitude">11°6′N</span> <span class="longitude">0°0′E</span></span></span><span class="geo-multi-punct"> / </span><span class="geo-nondefault"><span class="vcard"><span class="geo-dec" title="Maps, aerial photos, and other data for this location">11.100°N 0.000°E</span><span style="display:none"> / <span class="geo">11.100; 0.000</span></span><span style="display:none"> (<span class="fn org">Ghana</span>)</span></span></span></a></span></td>
<th scope="row"><span class="flagicon"><img alt="" src="//upload.wikimedia.org/wikipedia/commons/thumb/1/19/Flag_of_Ghana.svg/23px-Flag_of_Ghana.svg.png" width="23" height="15" class="thumbborder" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/1/19/Flag_of_Ghana.svg/35px-Flag_of_Ghana.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/1/19/Flag_of_Ghana.svg/45px-Flag_of_Ghana.svg.png 2x" data-file-width="450" data-file-height="300" /> </span><a href="/wiki/Ghana" title="Ghana">Ghana</a></th>
<td>For about 16 km</td>
</tr>
<tr>
<td><span class="plainlinks nourlexpansion"><a class="external text" href="//tools.wmflabs.org/geohack/geohack.php?pagename=Prime_meridian&params=10_57_N_0_0_E_type:country&title=Togo"><span class="geo-default"><span class="geo-dms" title="Maps, aerial photos, and other data for this location"><span class="latitude">10°57′N</span> <span class="longitude">0°0′E</span></span></span><span class="geo-multi-punct"> / </span><span class="geo-nondefault"><span class="vcard"><span class="geo-dec" title="Maps, aerial photos, and other data for this location">10.950°N 0.000°E</span><span style="display:none"> / <span class="geo">10.950; 0.000</span></span><span style="display:none"> (<span class="fn org">Togo</span>)</span></span></span></a></span></td>
<th scope="row"><span class="flagicon"><img alt="" src="//upload.wikimedia.org/wikipedia/commons/thumb/6/68/Flag_of_Togo.svg/23px-Flag_of_Togo.svg.png" width="23" height="14" class="thumbborder" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/6/68/Flag_of_Togo.svg/35px-Flag_of_Togo.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/6/68/Flag_of_Togo.svg/46px-Flag_of_Togo.svg.png 2x" data-file-width="809" data-file-height="500" /> </span><a href="/wiki/Togo" title="Togo">Togo</a></th>
<td>For about 39 km</td>
</tr>
<tr>
<td><span class="plainlinks nourlexpansion"><a class="external text" href="//tools.wmflabs.org/geohack/geohack.php?pagename=Prime_meridian&params=10_36_N_0_0_E_type:country&title=Ghana"><span class="geo-default"><span class="geo-dms" title="Maps, aerial photos, and other data for this location"><span class="latitude">10°36′N</span> <span class="longitude">0°0′E</span></span></span><span class="geo-multi-punct"> / </span><span class="geo-nondefault"><span class="vcard"><span class="geo-dec" title="Maps, aerial photos, and other data for this location">10.600°N 0.000°E</span><span style="display:none"> / <span class="geo">10.600; 0.000</span></span><span style="display:none"> (<span class="fn org">Ghana</span>)</span></span></span></a></span></td>
<th scope="row"><span class="flagicon"><img alt="" src="//upload.wikimedia.org/wikipedia/commons/thumb/1/19/Flag_of_Ghana.svg/23px-Flag_of_Ghana.svg.png" width="23" height="15" class="thumbborder" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/1/19/Flag_of_Ghana.svg/35px-Flag_of_Ghana.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/1/19/Flag_of_Ghana.svg/45px-Flag_of_Ghana.svg.png 2x" data-file-width="450" data-file-height="300" /> </span><a href="/wiki/Ghana" title="Ghana">Ghana</a></th>
<td>From the Togo-Ghana border near <a href="/wiki/Bunkpurugu" title="Bunkpurugu">Bunkpurugu</a> to <a href="/wiki/Tema,_Ghana" class="mw-redirect" title="Tema, Ghana">Tema</a><br />
Passing through <a href="/wiki/Lake_Volta" title="Lake Volta">Lake Volta</a> at <span class="plainlinks nourlexpansion"><a class="external text" href="//tools.wmflabs.org/geohack/geohack.php?pagename=Prime_meridian&params=7_48_N_0_0_E_type:waterbody_region:GH&title=Lake+Volta"><span class="geo-default"><span class="geo-dms" title="Maps, aerial photos, and other data for this location"><span class="latitude">7°48′N</span> <span class="longitude">0°0′E</span></span></span><span class="geo-multi-punct"> / </span><span class="geo-nondefault"><span class="vcard"><span class="geo-dec" title="Maps, aerial photos, and other data for this location">7.800°N 0.000°E</span><span style="display:none"> / <span class="geo">7.800; 0.000</span></span><span style="display:none"> (<span class="fn org">Lake Volta</span>)</span></span></span></a></span></td>
</tr>
<tr>
<td style="background:#b0e0e6;"><span class="plainlinks nourlexpansion"><a class="external text" href="//tools.wmflabs.org/geohack/geohack.php?pagename=Prime_meridian&params=5_37_N_0_0_E_type:waterbody&title=Atlantic+Ocean"><span class="geo-default"><span class="geo-dms" title="Maps, aerial photos, and other data for this location"><span class="latitude">5°37′N</span> <span class="longitude">0°0′E</span></span></span><span class="geo-multi-punct"> / </span><span class="geo-nondefault"><span class="vcard"><span class="geo-dec" title="Maps, aerial photos, and other data for this location">5.617°N 0.000°E</span><span style="display:none"> / <span class="geo">5.617; 0.000</span></span><span style="display:none"> (<span class="fn org">Atlantic Ocean</span>)</span></span></span></a></span></td>
<th scope="row" style="background:#b0e0e6;"><a href="/wiki/Atlantic_Ocean" title="Atlantic Ocean">Atlantic Ocean</a></th>
<td style="background:#b0e0e6;">Passing through the <a href="/wiki/Equator" title="Equator">Equator</a> at <span class="plainlinks nourlexpansion"><a class="external text" href="//tools.wmflabs.org/geohack/geohack.php?pagename=Prime_meridian&params=0_0_N_0_0_E_type:landmark&title=Equator"><span class="geo-default"><span class="geo-dms" title="Maps, aerial photos, and other data for this location"><span class="latitude">0°0′N</span> <span class="longitude">0°0′E</span></span></span><span class="geo-multi-punct"> / </span><span class="geo-nondefault"><span class="vcard"><span class="geo-dec" title="Maps, aerial photos, and other data for this location">0.000°N 0.000°E</span><span style="display:none"> / <span class="geo">0.000; 0.000</span></span><span style="display:none"> (<span class="fn org">Equator</span>)</span></span></span></a></span></td>
</tr>
<tr>
<td style="background:#b0e0e6;"><span class="plainlinks nourlexpansion"><a class="external text" href="//tools.wmflabs.org/geohack/geohack.php?pagename=Prime_meridian&params=60_0_S_0_0_E_type:waterbody&title=Southern+Ocean"><span class="geo-default"><span class="geo-dms" title="Maps, aerial photos, and other data for this location"><span class="latitude">60°0′S</span> <span class="longitude">0°0′E</span></span></span><span class="geo-multi-punct"> / </span><span class="geo-nondefault"><span class="vcard"><span class="geo-dec" title="Maps, aerial photos, and other data for this location">60.000°S 0.000°E</span><span style="display:none"> / <span class="geo">-60.000; 0.000</span></span><span style="display:none"> (<span class="fn org">Southern Ocean</span>)</span></span></span></a></span></td>
<th scope="row" style="background:#b0e0e6;"><a href="/wiki/Southern_Ocean" title="Southern Ocean">Southern Ocean</a></th>
<td style="background:#b0e0e6;"></td>
</tr>
<tr style="vertical-align:top;">
<td><span class="plainlinks nourlexpansion"><a class="external text" href="//tools.wmflabs.org/geohack/geohack.php?pagename=Prime_meridian&params=68_54_S_0_0_E_type:country&title=Antarctica"><span class="geo-default"><span class="geo-dms" title="Maps, aerial photos, and other data for this location"><span class="latitude">68°54′S</span> <span class="longitude">0°0′E</span></span></span><span class="geo-multi-punct"> / </span><span class="geo-nondefault"><span class="vcard"><span class="geo-dec" title="Maps, aerial photos, and other data for this location">68.900°S 0.000°E</span><span style="display:none"> / <span class="geo">-68.900; 0.000</span></span><span style="display:none"> (<span class="fn org">Antarctica</span>)</span></span></span></a></span></td>
<th scope="row"><a href="/wiki/Antarctica" title="Antarctica">Antarctica</a></th>
<td><a href="/wiki/Queen_Maud_Land" title="Queen Maud Land">Queen Maud Land</a>, <a href="/wiki/List_of_Antarctic_territorial_claims" class="mw-redirect" title="List of Antarctic territorial claims">claimed</a> by <span class="flagicon"><img alt="" src="//upload.wikimedia.org/wikipedia/commons/thumb/d/d9/Flag_of_Norway.svg/21px-Flag_of_Norway.svg.png" width="21" height="15" class="thumbborder" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/d/d9/Flag_of_Norway.svg/32px-Flag_of_Norway.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/d/d9/Flag_of_Norway.svg/41px-Flag_of_Norway.svg.png 2x" data-file-width="1100" data-file-height="800" /> </span><a href="/wiki/Norway" title="Norway">Norway</a></td>
</tr>
</table>
</dd>
</dl>
<h2><span class="mw-headline" id="Prime_meridian_on_other_planetary_bodies">Prime meridian on other planetary bodies<span id="Planets"></span></span><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Prime_meridian&action=edit&section=7" title="Edit section: Prime meridian on other planetary bodies">edit</a><span class="mw-editsection-bracket">]</span></span></h2>
<div role="note" class="hatnote">See also: <a href="/wiki/Longitude_(planets)" class="mw-redirect" title="Longitude (planets)">Longitude (planets)</a></div>
<div role="note" class="hatnote">"Prime meridian (planets)" redirects here. It is not to be confused with <a href="/wiki/Central_meridian_(planets)" title="Central meridian (planets)">Central meridian (planets)</a>.</div>
<p>As on the Earth, prime meridians must be arbitrarily defined. Often a landmark such as a crater is used; other times a prime meridian is defined by reference to another celestial object, or by <a href="/wiki/Magnetic_fields" class="mw-redirect" title="Magnetic fields">magnetic fields</a>. The prime meridians of the following planetographic systems have been defined:</p>
<ul>
<li>Two different <a href="/w/index.php?title=Heliographic_coordinate_system&action=edit&redlink=1" class="new" title="Heliographic coordinate system (page does not exist)">heliographic coordinate systems</a> are used on the Sun. The first is the Carrington heliographic coordinate system. In this system, the prime meridian passes through the center of the solar disk as seen from the Earth on 9 November 1853, which is when <a href="/wiki/Richard_Christopher_Carrington" title="Richard Christopher Carrington">Richard Christopher Carrington</a> started his observations of <a href="/wiki/Sunspots" class="mw-redirect" title="Sunspots">sunspots</a>.<sup id="cite_ref-38" class="reference"><a href="#cite_note-38">[37]</a></sup> The second is the <a href="/wiki/Stonyhurst_Observatory#Stonyhurst_heliographic_coordinates" title="Stonyhurst Observatory">Stonyhurst heliographic coordinates</a> system.</li>
<li>The prime meridian of <a href="/wiki/Mercury_(planet)" title="Mercury (planet)">Mercury</a> is defined to be 20° west of the crater <a href="/wiki/Hun_Kal_(crater)" title="Hun Kal (crater)">Hun Kal</a>.<sup id="cite_ref-39" class="reference"><a href="#cite_note-39">[38]</a></sup></li>
<li>The prime meridian of <a href="/wiki/Venus" title="Venus">Venus</a> passes through the central peak in the crater Ariadne.<sup id="cite_ref-40" class="reference"><a href="#cite_note-40">[39]</a></sup></li>
<li>The prime meridian of the <a href="/wiki/Moon" title="Moon">Moon</a> lies directly in the middle of the face of the moon visible from Earth and passes near the crater <a href="/wiki/Bruce_(crater)" title="Bruce (crater)">Bruce</a>.</li>
<li>The prime meridian of <a href="/wiki/Mars" title="Mars">Mars</a> is defined by the crater <a href="/wiki/Airy-0" title="Airy-0">Airy-0</a>.</li>
<li><a href="/wiki/Jupiter" title="Jupiter">Jupiter</a> has several coordinate systems because its cloud tops—the only part of the planet visible from space—rotate at different rates depending on latitude.<sup id="cite_ref-41" class="reference"><a href="#cite_note-41">[40]</a></sup> It is unknown whether Jupiter has any internal solid surface that would enable a more Earth-like coordinate system. System I and System II coordinates are based on atmospheric rotation, and System III coordinates use Jupiter's magnetic field.</li>
<li><a href="/wiki/Titan_(moon)" title="Titan (moon)">Titan</a>, like the Earth's moon, always has the same face towards Saturn, and so the middle of that face is 0 longitude.</li>
<li><a href="/wiki/Pluto" title="Pluto">Pluto</a>'s prime meridian is defined as the center of the face that is always pointed towards <a href="/wiki/Charon_(moon)" title="Charon (moon)">Charon</a>, its largest moon, as the two are tidally locked towards each other.</li>
</ul>
<h2><span class="mw-headline" id="See_also">See also</span><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Prime_meridian&action=edit&section=8" title="Edit section: See also">edit</a><span class="mw-editsection-bracket">]</span></span></h2>
<div role="navigation" aria-label="Portals" class="noprint portal plainlist tright" style="margin:0.5em 0 0.5em 1em;border:solid #aaa 1px">
<ul style="display:table;box-sizing:border-box;padding:0.1em;max-width:175px;background:#f9f9f9;font-size:85%;line-height:110%;font-style:italic;font-weight:bold">
<li style="display:table-row"><span style="display:table-cell;padding:0.2em;vertical-align:middle;text-align:center"><a href="/wiki/File:Terrestrial_globe.svg" class="image"><img alt="icon" src="//upload.wikimedia.org/wikipedia/en/thumb/6/6b/Terrestrial_globe.svg/29px-Terrestrial_globe.svg.png" width="29" height="28" class="noviewer" srcset="//upload.wikimedia.org/wikipedia/en/thumb/6/6b/Terrestrial_globe.svg/43px-Terrestrial_globe.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/6/6b/Terrestrial_globe.svg/58px-Terrestrial_globe.svg.png 2x" data-file-width="321" data-file-height="312" /></a></span><span style="display:table-cell;padding:0.2em 0.2em 0.2em 0.3em;vertical-align:middle"><a href="/wiki/Portal:Geography" title="Portal:Geography">Geography portal</a></span></li>
</ul>
</div>
<ul>
<li><a href="/wiki/1st_meridian_east" title="1st meridian east">1st meridian east</a></li>
<li><a href="/wiki/1st_meridian_west" title="1st meridian west">1st meridian west</a></li>
</ul>
<h2><span class="mw-headline" id="Notes">Notes</span><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Prime_meridian&action=edit&section=9" title="Edit section: Notes">edit</a><span class="mw-editsection-bracket">]</span></span></h2>
<div class="reflist" style="list-style-type: decimal;">
<ol class="references">
<li id="cite_note-note1884-28"><span class="mw-cite-backlink"><b><a href="#cite_ref-note1884_28-0">^</a></b></span> <span class="reference-text">Voting took place on 13 October and the resolutions were adopted on 22 October 1884.<sup id="cite_ref-27" class="reference"><a href="#cite_note-27">[27]</a></sup></span></li>
</ol>
</div>
<h2><span class="mw-headline" id="References">References</span><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Prime_meridian&action=edit&section=10" title="Edit section: References">edit</a><span class="mw-editsection-bracket">]</span></span></h2>
<div class="reflist columns references-column-width" style="-moz-column-width: 30em; -webkit-column-width: 30em; column-width: 30em; list-style-type: decimal;">
<ol class="references">
<li id="cite_note-1"><span class="mw-cite-backlink"><b><a href="#cite_ref-1">^</a></b></span> <span class="reference-text"><a rel="nofollow" class="external text" href="http://www.geog.port.ac.uk/webmap/hantsmap/hantsmap/meridian.htm">Prime Meridian</a>, geog.port.ac.uk</span></li>
<li id="cite_note-2"><span class="mw-cite-backlink"><b><a href="#cite_ref-2">^</a></b></span> <span class="reference-text"><a href="#CITEREFNorgate2006">Norgate 2006</a></span></li>
<li id="cite_note-3"><span class="mw-cite-backlink"><b><a href="#cite_ref-3">^</a></b></span> <span class="reference-text"><a href="#CITEREFHooker2006">Hooker 2006</a></span></li>
<li id="cite_note-4"><span class="mw-cite-backlink"><b><a href="#cite_ref-4">^</a></b></span> <span class="reference-text">e.g. <a href="/wiki/Jacob_Roggeveen" title="Jacob Roggeveen">Jacob Roggeveen</a> in 1722 reported the longitude of <a href="/wiki/Easter_Island" title="Easter Island">Easter Island</a> as 268° 45' (starting from Fuertaventura) in the Extract from the Official log of Jacob Roggeveen reproduced in <cite id="CITEREFBolton_Glanville_Corney1908" class="citation">Bolton Glanville Corney, ed. (1908), <a rel="nofollow" class="external text" href="https://archive.org/stream/voyagecaptaindo00unkngoog#page/n88/mode/2up"><i>The voyage of Don Felipe Gonzalez to Easter Island in 1770-1</i></a>, Hakluyt Society, p. 3<span class="reference-accessdate">, retrieved <span class="nowrap">13 January</span> 2013</span></cite><span title="ctx_ver=Z39.88-2004&rfr_id=info%3Asid%2Fen.wikipedia.org%3APrime+meridian&rft.btitle=The+voyage+of+Don+Felipe+Gonzalez+to+Easter+Island+in+1770-1&rft.date=1908&rft.genre=book&rft_id=https%3A%2F%2Farchive.org%2Fstream%2Fvoyagecaptaindo00unkngoog%23page%2Fn88%2Fmode%2F2up&rft.pages=3&rft.pub=Hakluyt+Society&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook" class="Z3988"><span style="display:none;"> </span></span></span></li>
<li id="cite_note-5"><span class="mw-cite-backlink"><b><a href="#cite_ref-5">^</a></b></span> <span class="reference-text">Speech by Pierre Janssen, director of the Paris observatory, at the first session of the <a rel="nofollow" class="external text" href="https://www.gutenberg.org/files/17759/17759-h/17759-h.htm#Page_73">Meridian Conference.</a></span></li>
<li id="cite_note-6"><span class="mw-cite-backlink"><b><a href="#cite_ref-6">^</a></b></span> <span class="reference-text"><a href="#CITEREFSobelAndrewes1998">Sobel & Andrewes 1998</a>, pp. 110–115</span></li>
<li id="cite_note-7"><span class="mw-cite-backlink"><b><a href="#cite_ref-7">^</a></b></span> <span class="reference-text"><a href="#CITEREFSobelAndrewes1998">Sobel & Andrewes 1998</a>, pp. 197–199</span></li>
<li id="cite_note-8"><span class="mw-cite-backlink"><b><a href="#cite_ref-8">^</a></b></span> <span class="reference-text"><cite class="citation web"><a rel="nofollow" class="external text" href="http://www.rmg.co.uk/discover/explore/prime-meridian-greenwich">"The Prime Meridian at Greenwich"</a>. Royal Museums Greenwich. n.d<span class="reference-accessdate">. Retrieved <span class="nowrap">28 March</span> 2016</span>.</cite><span title="ctx_ver=Z39.88-2004&rfr_id=info%3Asid%2Fen.wikipedia.org%3APrime+meridian&rft.btitle=The+Prime+Meridian+at+Greenwich&rft.genre=unknown&rft_id=http%3A%2F%2Fwww.rmg.co.uk%2Fdiscover%2Fexplore%2Fprime-meridian-greenwich&rft.pub=Royal+Museums+Greenwich&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook" class="Z3988"><span style="display:none;"> </span></span></span></li>
<li id="cite_note-9"><span class="mw-cite-backlink"><b><a href="#cite_ref-9">^</a></b></span> <span class="reference-text"><a rel="nofollow" class="external text" href="https://www.gutenberg.org/files/17759/17759-h/17759-h.htm">International Conference Held at Washington for the Purpose of Fixing a Prime Meridian and a Universal Day. October, 1884</a>. Project Gutenberg</span></li>
<li id="cite_note-Hooker_2006.2C_introduction-10"><span class="mw-cite-backlink">^ <a href="#cite_ref-Hooker_2006.2C_introduction_10-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-Hooker_2006.2C_introduction_10-1"><sup><i><b>b</b></i></sup></a> <a href="#cite_ref-Hooker_2006.2C_introduction_10-2"><sup><i><b>c</b></i></sup></a></span> <span class="reference-text">Hooker (2006), introduction.</span></li>
<li id="cite_note-WIRED-11"><span class="mw-cite-backlink">^ <a href="#cite_ref-WIRED_11-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-WIRED_11-1"><sup><i><b>b</b></i></sup></a> <a href="#cite_ref-WIRED_11-2"><sup><i><b>c</b></i></sup></a></span> <span class="reference-text"><a rel="nofollow" class="external text" href="http://www.wired.com/2010/10/1013greenwich-prime-meridian/">Oct. 13, 1884: Greenwich Resolves Subprime Meridian Crisis</a>, <i>WIRED</i>, 13 October 2010.</span></li>
<li id="cite_note-12"><span class="mw-cite-backlink"><b><a href="#cite_ref-12">^</a></b></span> <span class="reference-text"><a rel="nofollow" class="external text" href="http://www.maproom.org/00/49/index.php">Atlas do Brazil</a>, 1909, by Barão Homem de Mello e Francisco Homem de Mello, published in Rio de Janeiro by F. Briguiet & Cia.</span></li>
<li id="cite_note-gutenberg.org-13"><span class="mw-cite-backlink">^ <a href="#cite_ref-gutenberg.org_13-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-gutenberg.org_13-1"><sup><i><b>b</b></i></sup></a> <a href="#cite_ref-gutenberg.org_13-2"><sup><i><b>c</b></i></sup></a></span> <span class="reference-text"><cite class="citation web"><a rel="nofollow" class="external text" href="https://www.gutenberg.org/files/17759/17759-h/17759-h.htm">"The Project Gutenberg eBook of International Conference Held at Washington for the Purpose of Fixing a Prime Meridian and a Universal Day"</a>. Gutenberg.org. 12 February 2006<span class="reference-accessdate">. Retrieved <span class="nowrap">28 March</span> 2016</span>.</cite><span title="ctx_ver=Z39.88-2004&rfr_id=info%3Asid%2Fen.wikipedia.org%3APrime+meridian&rft.btitle=The+Project+Gutenberg+eBook+of+International+Conference+Held+at+Washington+for+the+Purpose+of+Fixing+a+Prime+Meridian+and+a+Universal+Day&rft.date=2006-02-12&rft.genre=unknown&rft_id=https%3A%2F%2Fwww.gutenberg.org%2Ffiles%2F17759%2F17759-h%2F17759-h.htm&rft.pub=Gutenberg.org&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook" class="Z3988"><span style="display:none;"> </span></span></span></li>
<li id="cite_note-14"><span class="mw-cite-backlink"><b><a href="#cite_ref-14">^</a></b></span> <span class="reference-text">Ancient, used in <a href="/wiki/Ptolemy" title="Ptolemy">Ptolemy</a>'s <i><a href="/wiki/Geographia" class="mw-redirect" title="Geographia">Geographia</a></i>. Later redefined 17° 39′ 46″ W of Greenwich to be exactly 20° W of Paris. French "submarin" at Washington 1884.</span></li>
<li id="cite_note-15"><span class="mw-cite-backlink"><b><a href="#cite_ref-15">^</a></b></span> <span class="reference-text">A.R.T. Jonkers; <a rel="nofollow" class="external text" href="http://www.liv.ac.uk/~jonkers/PARAMER.pdf">Parallel meridians: Diffusion and change in early modern oceanic reckoning</a>, in <i>Noord-Zuid in Oostindisch perspectief</i>, The Hague, 2005, p. 7. Retrieved 2 February 2015.</span></li>
<li id="cite_note-Bartky-16"><span class="mw-cite-backlink">^ <a href="#cite_ref-Bartky_16-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-Bartky_16-1"><sup><i><b>b</b></i></sup></a> <a href="#cite_ref-Bartky_16-2"><sup><i><b>c</b></i></sup></a> <a href="#cite_ref-Bartky_16-3"><sup><i><b>d</b></i></sup></a> <a href="#cite_ref-Bartky_16-4"><sup><i><b>e</b></i></sup></a></span> <span class="reference-text">Bartky, Ian R. (2007), <i>One Time Fits All: The Campaigns for Global Uniformity</i>, p. 98, retrieved through <a rel="nofollow" class="external text" href="https://books.google.com/books?id=rC6sAAAAIAAJ&pg=PA98&lpg=PA98&dq=initial+meridians+on+topographic+maps+1885&source=bl&ots=YGz_PabfPA&sig=_NgZ_MJirj07e3D-K8GEdv1d-fc&hl=nl&sa=X&ei=IaRoU9KEEonuOaShgegL&ved=0CDEQ6AEwAA#v=onepage&q=initial%20meridians%20on%20topographic%20maps%201885&f=false">GoogleBooks</a>, 6 May 2014.</span></li>
<li id="cite_note-FOOTNOTEDolan2013a-17"><span class="mw-cite-backlink">^ <a href="#cite_ref-FOOTNOTEDolan2013a_17-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-FOOTNOTEDolan2013a_17-1"><sup><i><b>b</b></i></sup></a> <a href="#cite_ref-FOOTNOTEDolan2013a_17-2"><sup><i><b>c</b></i></sup></a></span> <span class="reference-text"><a href="#CITEREFDolan2013a">Dolan 2013a</a>.</span></li>
<li id="cite_note-18"><span class="mw-cite-backlink"><b><a href="#cite_ref-18">^</a></b></span> <span class="reference-text"><span class="languageicon" style="font-size:0.95em; font-weight:bold; color:#555;">(Dutch)</span><a rel="nofollow" class="external text" href="http://www.staff.science.uu.nl/~gent0113/wettijd/wt_text3d.htm">Eenheid van tijd in Nederland (Unity of time in the Netherlands)</a>, Utrecht University website, retrieved 28 August 2013.</span></li>
<li id="cite_note-19"><span class="mw-cite-backlink"><b><a href="#cite_ref-19">^</a></b></span> <span class="reference-text"><a rel="nofollow" class="external text" href="http://www.asprs.org/a/resources/grids/08-2005-italy.pdf">Grids & Datums – Italian Republic</a>, asprs.org, Retrieved 10 December 2013.</span></li>
<li id="cite_note-20"><span class="mw-cite-backlink"><b><a href="#cite_ref-20">^</a></b></span> <span class="reference-text"><i><a rel="nofollow" class="external text" href="http://www.denstoredanske.dk/index.php?sideId=124327">meridian</a></i>, article from <a href="/wiki/Den_Store_Danske_Encyklop%C3%A6di" title="Den Store Danske Encyklopædi">Den Store Danske Encyklopædi</a></span></li>
<li id="cite_note-21"><span class="mw-cite-backlink"><b><a href="#cite_ref-21">^</a></b></span> <span class="reference-text"><a rel="nofollow" class="external text" href="http://romaniatourism.com/oradea.html">Oradea</a>, Tourism office website, retrieved 3 February 2015.</span></li>
<li id="cite_note-22"><span class="mw-cite-backlink"><b><a href="#cite_ref-22">^</a></b></span> <span class="reference-text">The meridian of <a href="/wiki/Ptolemy" title="Ptolemy">Ptolemy</a>'s <a href="/wiki/Almagest" title="Almagest">Almagest</a>.</span></li>
<li id="cite_note-23"><span class="mw-cite-backlink"><b><a href="#cite_ref-23">^</a></b></span> <span class="reference-text">Wilcomb E. Washburn, "<a rel="nofollow" class="external text" href="http://muweb.millersville.edu/~columbus/data/geo/WASHBR04.GEO">The Canary Islands and the Question of the Prime Meridian: The Search for Precision in the Measurement of the Earth</a>"</span></li>
<li id="cite_note-24"><span class="mw-cite-backlink"><b><a href="#cite_ref-24">^</a></b></span> <span class="reference-text"><a href="/wiki/Maimonides" title="Maimonides">Maimonides</a>, <a rel="nofollow" class="external text" href="http://mechon-mamre.org/i/3811.htm#17"><i>Hilchot Kiddush Hachodesh</i> 11:17</a>, calls this point אמצע היישוב, "the middle of the habitation", i.e. the habitable hemisphere. Evidently this was a convention accepted by Arab geographers of his day.</span></li>
<li id="cite_note-25"><span class="mw-cite-backlink"><b><a href="#cite_ref-25">^</a></b></span> <span class="reference-text"><a href="#CITEREFBurgessc._2013">Burgess c. 2013</a></span></li>
<li id="cite_note-imc-26"><span class="mw-cite-backlink"><b><a href="#cite_ref-imc_26-0">^</a></b></span> <span class="reference-text"><cite class="citation web"><a rel="nofollow" class="external text" href="https://www.gutenberg.org/files/17759/17759-h/17759-h.htm">"International Conference Held at Washington for the Purpose of Fixing a Prime Meridian and a Universal Day. October, 1884. Protocols of the proceedings"</a>. Project Gutenberg. 1884<span class="reference-accessdate">. Retrieved <span class="nowrap">30 November</span> 2012</span>.</cite><span title="ctx_ver=Z39.88-2004&rfr_id=info%3Asid%2Fen.wikipedia.org%3APrime+meridian&rft.btitle=International+Conference+Held+at+Washington+for+the+Purpose+of+Fixing+a+Prime+Meridian+and+a+Universal+Day.+October%2C+1884.+Protocols+of+the+proceedings&rft.date=1884&rft.genre=unknown&rft_id=https%3A%2F%2Fwww.gutenberg.org%2Ffiles%2F17759%2F17759-h%2F17759-h.htm&rft.pub=Project+Gutenberg&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook" class="Z3988"><span style="display:none;"> </span></span></span></li>
<li id="cite_note-27"><span class="mw-cite-backlink"><b><a href="#cite_ref-27">^</a></b></span> <span class="reference-text"><a href="#CITEREFHowse1997">Howse 1997</a>, pp. 12, 137</span></li>
<li id="cite_note-Greenwich_Observatory_p.10-29"><span class="mw-cite-backlink">^ <a href="#cite_ref-Greenwich_Observatory_p.10_29-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-Greenwich_Observatory_p.10_29-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text">Greenwich Observatory ... the story of Britain's oldest scientific institution, the Royal Observatory at Greenwich and Herstmonceux, 1675–1975 p.10. Taylor & Francis, 1975</span></li>
<li id="cite_note-Time-30"><span class="mw-cite-backlink"><b><a href="#cite_ref-Time_30-0">^</a></b></span> <span class="reference-text"><cite class="citation book"><a href="/wiki/Dennis_McCarthy_(scientist)" title="Dennis McCarthy (scientist)">McCarthy, Dennis</a>; Seidelmann, P. Kenneth (2009). <i>TIME from Earth Rotation to Atomic Physics</i>. Weinheim: Wiley-VCH. pp. 244–5.</cite><span title="ctx_ver=Z39.88-2004&rfr_id=info%3Asid%2Fen.wikipedia.org%3APrime+meridian&rft.aufirst=Dennis&rft.aulast=McCarthy&rft.au=Seidelmann%2C+P.+Kenneth&rft.btitle=TIME+from+Earth+Rotation+to+Atomic+Physics&rft.date=2009&rft.genre=book&rft.pages=244-5&rft.place=Weinheim&rft.pub=Wiley-VCH&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook" class="Z3988"><span style="display:none;"> </span></span></span></li>
<li id="cite_note-RMG-31"><span class="mw-cite-backlink"><b><a href="#cite_ref-RMG_31-0">^</a></b></span> <span class="reference-text"><cite class="citation web">ROG Learing Team (23 August 2002). <a rel="nofollow" class="external text" href="http://www.rmg.co.uk/explore/astronomy-and-time/astronomy-facts/history/the-prime-meridian-at-greenwich">"The Prime Meridian at Greenwich"</a>. <i>Royal Museums Greenwich</i>. Royal Museums Greenwich<span class="reference-accessdate">. Retrieved <span class="nowrap">14 June</span> 2012</span>.</cite><span title="ctx_ver=Z39.88-2004&rfr_id=info%3Asid%2Fen.wikipedia.org%3APrime+meridian&rft.atitle=The+Prime+Meridian+at+Greenwich&rft.au=ROG+Learing+Team&rft.date=2002-08-23&rft.genre=unknown&rft_id=http%3A%2F%2Fwww.rmg.co.uk%2Fexplore%2Fastronomy-and-time%2Fastronomy-facts%2Fhistory%2Fthe-prime-meridian-at-greenwich&rft.jtitle=Royal+Museums+Greenwich&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal" class="Z3988"><span style="display:none;"> </span></span></span></li>
<li id="cite_note-32"><span class="mw-cite-backlink"><b><a href="#cite_ref-32">^</a></b></span> <span class="reference-text"><cite class="citation journal">Malys, Stephen; Seago, John H.; Palvis, Nikolaos K.; Seidelmann, P. Kenneth; Kaplan, George H. (1 August 2015). <a rel="nofollow" class="external text" href="http://link.springer.com/article/10.1007%2Fs00190-015-0844-y">"Why the Greenwich meridian moved"</a>. <i>Journal of Geodesy</i>. <a href="/wiki/Bibcode" title="Bibcode">Bibcode</a>:<a rel="nofollow" class="external text" href="http://adsabs.harvard.edu/abs/2015JGeod..89.1263M">2015JGeod..89.1263M</a>. <a href="/wiki/Digital_object_identifier" title="Digital object identifier">doi</a>:<a rel="nofollow" class="external text" href="//dx.doi.org/10.1007%2Fs00190-015-0844-y">10.1007/s00190-015-0844-y</a>.</cite><span title="ctx_ver=Z39.88-2004&rfr_id=info%3Asid%2Fen.wikipedia.org%3APrime+meridian&rft.atitle=Why+the+Greenwich+meridian+moved&rft.aufirst=Stephen&rft.au=Kaplan%2C+George+H.&rft.aulast=Malys&rft.au=Palvis%2C+Nikolaos+K.&rft.au=Seago%2C+John+H.&rft.au=Seidelmann%2C+P.+Kenneth&rft.date=2015-08-01&rft.genre=article&rft_id=http%3A%2F%2Flink.springer.com%2Farticle%2F10.1007%252Fs00190-015-0844-y&rft_id=info%3Abibcode%2F2015JGeod..89.1263M&rft_id=info%3Adoi%2F10.1007%2Fs00190-015-0844-y&rft.jtitle=Journal+of+Geodesy&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal" class="Z3988"><span style="display:none;"> </span></span></span></li>
<li id="cite_note-FOOTNOTEDolan2013b-33"><span class="mw-cite-backlink"><b><a href="#cite_ref-FOOTNOTEDolan2013b_33-0">^</a></b></span> <span class="reference-text"><a href="#CITEREFDolan2013b">Dolan 2013b</a>.</span></li>
<li id="cite_note-GPS-34"><span class="mw-cite-backlink">^ <a href="#cite_ref-GPS_34-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-GPS_34-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"><a rel="nofollow" class="external text" href="http://gpsinformation.net/main/greenwich.htm">History of the Prime Meridian -Past and Present</a></span></li>
<li id="cite_note-IRM-35"><span class="mw-cite-backlink">^ <a href="#cite_ref-IRM_35-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-IRM_35-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"><a rel="nofollow" class="external text" href="http://www.gearthblog.com/images/images2006/primemeridian.jpg">IRM on grounds of Royal Observatory from Google Earth</a> Accessed 30 March 2012</span></li>
<li id="cite_note-Observatory-36"><span class="mw-cite-backlink">^ <a href="#cite_ref-Observatory_36-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-Observatory_36-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text">The astronomic latitude of the Royal Observatory is 51°28'38"N whereas its latitude on the European Terrestrial Reference Frame (1989) <a href="/wiki/Datum_(geodesy)" class="mw-redirect" title="Datum (geodesy)">datum</a> is 51°28'40.1247"N.</span></li>
<li id="cite_note-37"><span class="mw-cite-backlink"><b><a href="#cite_ref-37">^</a></b></span> <span class="reference-text">Guinot, B., 2011. <a rel="nofollow" class="external text" href="http://iopscience.iop.org/0026-1394/48/4">Solar time, legal time, time in use</a>. Metrologica 48, S181–S185.</span></li>
<li id="cite_note-38"><span class="mw-cite-backlink"><b><a href="#cite_ref-38">^</a></b></span> <span class="reference-text"><cite class="citation web"><a rel="nofollow" class="external text" href="http://www.encyclopedia.com/doc/1O80-Carringtonheligrphccrdnts.html">"Carrington heliographic coordinates"</a>.</cite><span title="ctx_ver=Z39.88-2004&rfr_id=info%3Asid%2Fen.wikipedia.org%3APrime+meridian&rft.btitle=Carrington+heliographic+coordinates&rft.genre=unknown&rft_id=http%3A%2F%2Fwww.encyclopedia.com%2Fdoc%2F1O80-Carringtonheligrphccrdnts.html&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook" class="Z3988"><span style="display:none;"> </span></span></span></li>
<li id="cite_note-39"><span class="mw-cite-backlink"><b><a href="#cite_ref-39">^</a></b></span> <span class="reference-text"><cite class="citation journal">Archinal, B. A.; A’Hearn, M. F.; Bowell, E.; Conrad, A.; Consolmagno, G. J.; Courtin, R.; Fukushima, T.; Hestroffer, D.; Hilton, J. L.; Krasinsky, G. A.; Neumann, G.; Oberst, J.; Seidelmann, P. K.; Stooke, P.; Tholen, D. J.; Thomas, P. C.; Williams, I. P. (23 October 2010). <a rel="nofollow" class="external text" href="http://astropedia.astrogeology.usgs.gov/download/Docs/WGCCRE/WGCCRE2009reprint.pdf">"Report of the IAU Working Group on Cartographic Coordinates and Rotational Elements: 2009"</a> <span style="font-size:85%;">(PDF)</span>. <i>Celestial Mechanics and Dynamical Astronomy</i>: 15. <a href="/wiki/Digital_object_identifier" title="Digital object identifier">doi</a>:<a rel="nofollow" class="external text" href="//dx.doi.org/10.1007%2Fs10569-010-9320-4">10.1007/s10569-010-9320-4</a>.</cite><span title="ctx_ver=Z39.88-2004&rfr_id=info%3Asid%2Fen.wikipedia.org%3APrime+meridian&rft.atitle=Report+of+the+IAU+Working+Group+on+Cartographic+Coordinates+and+Rotational+Elements%3A+2009&rft.au=A%99Hearn%2C+M.+F.&rft.au=Bowell%2C+E.&rft.au=Conrad%2C+A.&rft.au=Consolmagno%2C+G.+J.&rft.au=Courtin%2C+R.&rft.aufirst=B.+A.&rft.au=Fukushima%2C+T.&rft.au=Hestroffer%2C+D.&rft.au=Hilton%2C+J.+L.&rft.au=Krasinsky%2C+G.+A.&rft.aulast=Archinal&rft.au=Neumann%2C+G.&rft.au=Oberst%2C+J.&rft.au=Seidelmann%2C+P.+K.&rft.au=Stooke%2C+P.&rft.au=Tholen%2C+D.+J.&rft.au=Thomas%2C+P.+C.&rft.au=Williams%2C+I.+P.&rft.date=2010-10-23&rft.genre=article&rft_id=http%3A%2F%2Fastropedia.astrogeology.usgs.gov%2Fdownload%2FDocs%2FWGCCRE%2FWGCCRE2009reprint.pdf&rft_id=info%3Adoi%2F10.1007%2Fs10569-010-9320-4&rft.jtitle=Celestial+Mechanics+and+Dynamical+Astronomy&rft.pages=15&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal" class="Z3988"><span style="display:none;"> </span></span></span></li>
<li id="cite_note-40"><span class="mw-cite-backlink"><b><a href="#cite_ref-40">^</a></b></span> <span class="reference-text"><cite class="citation web"><a rel="nofollow" class="external text" href="http://astrogeology.usgs.gov/Projects/WGCCRE/constants/iau2000_table1.html">"USGS Astrogeology: Rotation and pole position for the Sun and planets (IAU WGCCRE)"</a><span class="reference-accessdate">. Retrieved <span class="nowrap">22 October</span> 2009</span>.</cite><span title="ctx_ver=Z39.88-2004&rfr_id=info%3Asid%2Fen.wikipedia.org%3APrime+meridian&rft.btitle=USGS+Astrogeology%3A+Rotation+and+pole+position+for+the+Sun+and+planets+%28IAU+WGCCRE%29&rft.genre=unknown&rft_id=http%3A%2F%2Fastrogeology.usgs.gov%2FProjects%2FWGCCRE%2Fconstants%2Fiau2000_table1.html&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook" class="Z3988"><span style="display:none;"> </span></span></span></li>
<li id="cite_note-41"><span class="mw-cite-backlink"><b><a href="#cite_ref-41">^</a></b></span> <span class="reference-text"><cite class="citation web"><a rel="nofollow" class="external text" href="http://documents.wolfram.com/applications/astronomer/AdditionalInformation/PlanetographicCoordinates.html">"Planetographic Coordinates"</a><span class="reference-accessdate">. Retrieved <span class="nowrap">19 June</span> 2009</span>.</cite><span title="ctx_ver=Z39.88-2004&rfr_id=info%3Asid%2Fen.wikipedia.org%3APrime+meridian&rft.btitle=Planetographic+Coordinates&rft.genre=unknown&rft_id=http%3A%2F%2Fdocuments.wolfram.com%2Fapplications%2Fastronomer%2FAdditionalInformation%2FPlanetographicCoordinates.html&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook" class="Z3988"><span style="display:none;"> </span></span></span></li>
</ol>
</div>
<ul>
<li><cite id="CITEREFBurgess1860" class="citation">Burgess, Ebenezer (1860), "Translation of the Surya-Siddhanta", <i>Journal of the American Oriental Society</i> (e book), <b>6</b>, Google (published c. 2013), p. 185</cite><span title="ctx_ver=Z39.88-2004&rfr_id=info%3Asid%2Fen.wikipedia.org%3APrime+meridian&rft.atitle=Translation+of+the+Surya-Siddhanta&rft.aufirst=Ebenezer&rft.aulast=Burgess&rft.btitle=Journal+of+the+American+Oriental+Society&rft.date=1860&rft.genre=bookitem&rft.pages=185&rft.pub=Google&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook" class="Z3988"><span style="display:none;"> </span></span></li>
</ul>
<ul>
<li><cite id="CITEREFDolan2013a" class="citation web">Dolan, Graham (2013a). <a rel="nofollow" class="external text" href="http://www.thegreenwichmeridian.org/tgm/articles.php?article=8">"The Greenwich Meridian before the Airy Transit Circle"</a>. <i>The Greenwich Meridian</i>.</cite><span title="ctx_ver=Z39.88-2004&rfr_id=info%3Asid%2Fen.wikipedia.org%3APrime+meridian&rft.atitle=The+Greenwich+Meridian+before+the+Airy+Transit+Circle&rft.aufirst=Graham&rft.aulast=Dolan&rft.date=2013&rft.genre=unknown&rft_id=http%3A%2F%2Fwww.thegreenwichmeridian.org%2Ftgm%2Farticles.php%3Farticle%3D8&rft.jtitle=The+Greenwich+Meridian&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal" class="Z3988"><span style="display:none;"> </span></span></li>
</ul>
<ul>
<li><cite id="CITEREFDolan2013b" class="citation web">Dolan, Graham (2013b). <a rel="nofollow" class="external text" href="http://www.thegreenwichmeridian.org/tgm/articles.php?article=7">"WGS84 and the Greenwich Meridian"</a>. <i>The Greenwich Meridian</i>.</cite><span title="ctx_ver=Z39.88-2004&rfr_id=info%3Asid%2Fen.wikipedia.org%3APrime+meridian&rft.atitle=WGS84+and+the+Greenwich+Meridian&rft.aufirst=Graham&rft.aulast=Dolan&rft.date=2013&rft.genre=unknown&rft_id=http%3A%2F%2Fwww.thegreenwichmeridian.org%2Ftgm%2Farticles.php%3Farticle%3D7&rft.jtitle=The+Greenwich+Meridian&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal" class="Z3988"><span style="display:none;"> </span></span></li>
</ul>
<h2><span class="mw-headline" id="Further_reading">Further reading</span><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Prime_meridian&action=edit&section=11" title="Edit section: Further reading">edit</a><span class="mw-editsection-bracket">]</span></span></h2>
<ul>
<li><cite id="CITEREFHooker2006" class="citation">Hooker, Brian (2006), <a rel="nofollow" class="external text" href="http://zeehaen.tripod.com/unpub_2/multitude_meridians.htm"><i>A multitude of prime meridians</i></a><span class="reference-accessdate">, retrieved <span class="nowrap">13 January</span> 2013</span></cite><span title="ctx_ver=Z39.88-2004&rfr_id=info%3Asid%2Fen.wikipedia.org%3APrime+meridian&rft.aufirst=Brian&rft.aulast=Hooker&rft.btitle=A+multitude+of+prime+meridians&rft.date=2006&rft.genre=book&rft_id=http%3A%2F%2Fzeehaen.tripod.com%2Funpub_2%2Fmultitude_meridians.htm&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook" class="Z3988"><span style="display:none;"> </span></span></li>
<li><cite id="CITEREFNorgate2006" class="citation">Norgate, Jean and Martin (2006), <a rel="nofollow" class="external text" href="http://www.geog.port.ac.uk/webmap/hantsmap/hantsmap/meridian.htm"><i>Prime meridian</i></a><span class="reference-accessdate">, retrieved <span class="nowrap">13 January</span> 2013</span></cite><span title="ctx_ver=Z39.88-2004&rfr_id=info%3Asid%2Fen.wikipedia.org%3APrime+meridian&rft.aufirst=Jean+and+Martin&rft.aulast=Norgate&rft.btitle=Prime+meridian&rft.date=2006&rft.genre=book&rft_id=http%3A%2F%2Fwww.geog.port.ac.uk%2Fwebmap%2Fhantsmap%2Fhantsmap%2Fmeridian.htm&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook" class="Z3988"><span style="display:none;"> </span></span></li>
<li><cite id="CITEREFSobelAndrewes1998" class="citation">Sobel, Dava; Andrewes, William J. H. (1998), <i><a href="/wiki/The_Illustrated_Longitude" class="mw-redirect" title="The Illustrated Longitude">The Illustrated Longitude</a></i>, Fourth Estate, London</cite><span title="ctx_ver=Z39.88-2004&rfr_id=info%3Asid%2Fen.wikipedia.org%3APrime+meridian&rft.au=Andrewes%2C+William+J.+H.&rft.aufirst=Dava&rft.aulast=Sobel&rft.btitle=The+Illustrated+Longitude&rft.date=1998&rft.genre=book&rft.pub=Fourth+Estate%2C+London&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook" class="Z3988"><span style="display:none;"> </span></span></li>
<li><cite id="CITEREFHowse1997" class="citation">Howse, Derek (1997), <a rel="nofollow" class="external text" href="http://www.amazon.co.uk/Greenwich-Time-Longitude-Derek-Howse/dp/0948065265"><i>Greenwich Time and the Longitude</i></a>, Phillip Wilson, <a href="/wiki/International_Standard_Book_Number" title="International Standard Book Number">ISBN</a> <a href="/wiki/Special:BookSources/0-85667-468-0" title="Special:BookSources/0-85667-468-0">0-85667-468-0</a></cite><span title="ctx_ver=Z39.88-2004&rfr_id=info%3Asid%2Fen.wikipedia.org%3APrime+meridian&rft.aufirst=Derek&rft.aulast=Howse&rft.btitle=Greenwich+Time+and+the+Longitude&rft.date=1997&rft.genre=book&rft_id=http%3A%2F%2Fwww.amazon.co.uk%2FGreenwich-Time-Longitude-Derek-Howse%2Fdp%2F0948065265&rft.isbn=0-85667-468-0&rft.pub=Phillip+Wilson&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook" class="Z3988"><span style="display:none;"> </span></span></li>
</ul>
<h2><span class="mw-headline" id="External_links">External links</span><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Prime_meridian&action=edit&section=12" title="Edit section: External links">edit</a><span class="mw-editsection-bracket">]</span></span></h2>
<table role="presentation" class="mbox-small plainlinks sistersitebox" style="border:1px solid #aaa;background-color:#f9f9f9">
<tr>
<td class="mbox-image"><a href="/wiki/File:Commons-logo.svg" class="image"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/30px-Commons-logo.svg.png" width="30" height="40" class="noviewer" srcset="//upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/45px-Commons-logo.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/59px-Commons-logo.svg.png 2x" data-file-width="1024" data-file-height="1376" /></a></td>
<td class="mbox-text plainlist">Wikimedia Commons has media related to <i><b><a href="https://commons.wikimedia.org/wiki/Category:Prime_meridian" class="extiw" title="commons:Category:Prime meridian">Prime meridian</a></b></i>.</td>
</tr>
</table>
<ul>
<li><a rel="nofollow" class="external text" href="http://books.google.com/books?id=qOIDAAAAMBAJ&pg=PA927">"Where the Earth's surface begins—and ends"</a>, <i>Popular Mechanics</i>, December 1930</li>
<li><a rel="nofollow" class="external text" href="http://www.ucolick.org/~sla/leapsecs/scans-meridian.html">scanned TIFFs of the conference proceedings</a></li>
<li><a rel="nofollow" class="external text" href="http://wwp.greenwichmeantime.com/info/prime-meridian.htm">Prime meridians in use in the 1880s, by country</a></li>
</ul>
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<div id="Time_measurement_and_standards" style="font-size:114%"><a href="/wiki/Time" title="Time">Time measurement</a> and <a href="/wiki/Time_standard" title="Time standard">standards</a></div>
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<li><a href="/wiki/Chronometry" title="Chronometry">Chronometry</a></li>
<li><a href="/wiki/Orders_of_magnitude_(time)" title="Orders of magnitude (time)">Orders of magnitude</a></li>
<li><a href="/wiki/Metrology" title="Metrology">Metrology</a></li>
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<th scope="row" class="navbox-group" style="text-align:center;">International standards</th>
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<div style="padding:0em 0.25em">
<ul>
<li><b><a href="/wiki/Coordinated_Universal_Time" title="Coordinated Universal Time">UTC</a></b></li>
<li><a href="/wiki/UTC_offset" title="UTC offset">UTC offset</a></li>
<li><a href="/wiki/Universal_Time" title="Universal Time">UT</a></li>
<li><a href="/wiki/%CE%94T" title="ΔT">ΔT</a></li>
<li><a href="/wiki/DUT1" title="DUT1">DUT1</a></li>
<li><a href="/wiki/International_Earth_Rotation_and_Reference_Systems_Service" title="International Earth Rotation and Reference Systems Service">IERS</a></li>
<li><a href="/wiki/ISO_31-1" title="ISO 31-1">ISO 31-1</a></li>
<li><a href="/wiki/ISO_8601" title="ISO 8601">ISO 8601</a></li>
<li><a href="/wiki/International_Atomic_Time" title="International Atomic Time">TAI</a></li>
<li><a href="/wiki/12-hour_clock" title="12-hour clock">12-hour clock</a></li>
<li><a href="/wiki/24-hour_clock" title="24-hour clock">24-hour clock</a></li>
<li><a href="/wiki/Barycentric_Coordinate_Time" title="Barycentric Coordinate Time">Barycentric Coordinate Time</a></li>
<li><a href="/wiki/Barycentric_Dynamical_Time" title="Barycentric Dynamical Time">Barycentric Dynamical Time</a></li>
<li><a href="/wiki/Civil_time" title="Civil time">Civil time</a></li>
<li><a href="/wiki/Daylight_saving_time" title="Daylight saving time">Daylight saving time</a></li>
<li><a href="/wiki/Geocentric_Coordinate_Time" title="Geocentric Coordinate Time">Geocentric Coordinate Time</a></li>
<li><a href="/wiki/International_Date_Line" title="International Date Line">International Date Line</a></li>
<li><a href="/wiki/Leap_second" title="Leap second">Leap second</a></li>
<li><a href="/wiki/Solar_time" title="Solar time">Solar time</a></li>
<li><a href="/wiki/Terrestrial_Time" title="Terrestrial Time">Terrestrial Time</a></li>
<li><a href="/wiki/Time_zone" title="Time zone">Time zone</a></li>
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<th scope="row" class="navbox-group" style="text-align:center;">Obsolete standards</th>
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<ul>
<li><a href="/wiki/Ephemeris_time" title="Ephemeris time">Ephemeris time</a></li>
<li><a href="/wiki/Greenwich_Mean_Time" title="Greenwich Mean Time">Greenwich Mean Time</a></li>
<li><strong class="selflink">Prime meridian</strong></li>
</ul>
</div>
</td>
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<th scope="row" class="navbox-group" style="text-align:center;"><a href="/wiki/Time_in_physics" title="Time in physics">Time in physics</a></th>
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<div style="padding:0em 0.25em">
<ul>
<li><a href="/wiki/Absolute_time_and_space" title="Absolute time and space">Absolute time and space</a></li>
<li><a href="/wiki/Spacetime" title="Spacetime">Spacetime</a></li>
<li><a href="/wiki/Chronon" title="Chronon">Chronon</a></li>
<li><a href="/wiki/Continuous_signal" title="Continuous signal">Continuous time</a></li>
<li><a href="/wiki/Coordinate_time" title="Coordinate time">Coordinate time</a></li>
<li><a href="/wiki/Cosmological_decade" title="Cosmological decade">Cosmological decade</a></li>
<li><a href="/wiki/Discrete_time_and_continuous_time" title="Discrete time and continuous time">Discrete time</a></li>
<li><a href="/wiki/Planck_epoch" class="mw-redirect" title="Planck epoch">Planck epoch</a></li>
<li><a href="/wiki/Planck_time" title="Planck time">Planck time</a></li>
<li><a href="/wiki/Proper_time" title="Proper time">Proper time</a></li>
<li><a href="/wiki/Theory_of_relativity" title="Theory of relativity">Theory of relativity</a></li>
<li><a href="/wiki/Time_dilation" title="Time dilation">Time dilation</a></li>
<li><a href="/wiki/Gravitational_time_dilation" title="Gravitational time dilation">Gravitational time dilation</a></li>
<li><a href="/wiki/Time_domain" title="Time domain">Time domain</a></li>
<li><a href="/wiki/T-symmetry" title="T-symmetry">T-symmetry</a></li>
</ul>
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<th scope="row" class="navbox-group" style="text-align:center;"><a href="/wiki/Horology" title="Horology">Horology</a></th>
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<div style="padding:0em 0.25em">
<ul>
<li><b><a href="/wiki/Clock" title="Clock">Clock</a></b></li>
<li><a href="/wiki/Astrarium" title="Astrarium">Astrarium</a></li>
<li><a href="/wiki/Atomic_clock" title="Atomic clock">Atomic clock</a></li>
<li><a href="/wiki/Complication_(horology)" title="Complication (horology)">Complication</a></li>
<li><a href="/wiki/History_of_timekeeping_devices" title="History of timekeeping devices">History of timekeeping devices</a></li>
<li><a href="/wiki/Hourglass" title="Hourglass">Hourglass</a></li>
<li><a href="/wiki/Marine_chronometer" title="Marine chronometer">Marine chronometer</a></li>
<li><a href="/wiki/Marine_sandglass" title="Marine sandglass">Marine sandglass</a></li>
<li><a href="/wiki/Radio_clock" title="Radio clock">Radio clock</a></li>
<li><a href="/wiki/Watch" title="Watch">Watch</a></li>
<li><a href="/wiki/Water_clock" title="Water clock">Water clock</a></li>
<li><a href="/wiki/Sundial" title="Sundial">Sundial</a></li>
<li><a href="/wiki/Dialing_scales" title="Dialing scales">Dialing scales</a></li>
<li><a href="/wiki/Equation_of_time" title="Equation of time">Equation of time</a></li>
<li><a href="/wiki/History_of_sundials" title="History of sundials">History of sundials</a></li>
<li><a href="/wiki/Schema_for_horizontal_dials" title="Schema for horizontal dials">Sundial markup schema</a></li>
</ul>
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<th scope="row" class="navbox-group" style="text-align:center;"><a href="/wiki/Calendar" title="Calendar">Calendar</a></th>
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<div style="padding:0em 0.25em">
<ul>
<li><a href="/wiki/Astronomical_year_numbering" title="Astronomical year numbering">Astronomical</a></li>
<li><a href="/wiki/Dominical_letter" title="Dominical letter">Dominical letter</a></li>
<li><a href="/wiki/Epact" title="Epact">Epact</a></li>
<li><a href="/wiki/Equinox" title="Equinox">Equinox</a></li>
<li><a href="/wiki/Gregorian_calendar" title="Gregorian calendar">Gregorian</a></li>
<li><a href="/wiki/Hebrew_calendar" title="Hebrew calendar">Hebrew</a></li>
<li><a href="/wiki/Hindu_calendar" title="Hindu calendar">Hindu</a></li>
<li><a href="/wiki/Intercalation_(timekeeping)" title="Intercalation (timekeeping)">Intercalation</a></li>
<li><a href="/wiki/Islamic_calendar" title="Islamic calendar">Islamic</a></li>
<li><a href="/wiki/Julian_calendar" title="Julian calendar">Julian</a></li>
<li><a href="/wiki/Leap_year" title="Leap year">Leap year</a></li>
<li><a href="/wiki/Lunar_calendar" title="Lunar calendar">Lunar</a></li>
<li><a href="/wiki/Lunisolar_calendar" title="Lunisolar calendar">Lunisolar</a></li>
<li><a href="/wiki/Solar_calendar" title="Solar calendar">Solar</a></li>
<li><a href="/wiki/Solstice" title="Solstice">Solstice</a></li>
<li><a href="/wiki/Tropical_year" title="Tropical year">Tropical year</a></li>
<li><a href="/wiki/Determination_of_the_day_of_the_week" title="Determination of the day of the week">Weekday determination</a></li>
<li><a href="/wiki/Names_of_the_days_of_the_week" title="Names of the days of the week">Weekday names</a></li>
</ul>
</div>
</td>
</tr>
<tr style="height:2px">
<td colspan="2"></td>
</tr>
<tr>
<th scope="row" class="navbox-group" style="text-align:center;">Archaeology and geology</th>
<td class="navbox-list navbox-odd hlist" style="text-align:left;border-left-width:2px;border-left-style:solid;width:100%;padding:0px">
<div style="padding:0em 0.25em">
<ul>
<li><a href="/wiki/Chronological_dating" title="Chronological dating">Chronological dating</a></li>
<li><a href="/wiki/Dating_methodologies_in_archaeology" class="mw-redirect" title="Dating methodologies in archaeology">Dating methodologies in archaeology</a></li>
<li><a href="/wiki/Geologic_time_scale" title="Geologic time scale">Geologic time scale</a></li>
<li><a href="/wiki/International_Commission_on_Stratigraphy" title="International Commission on Stratigraphy">International Commission on Stratigraphy</a></li>
</ul>
</div>
</td>
</tr>
<tr style="height:2px">
<td colspan="2"></td>
</tr>
<tr>
<th scope="row" class="navbox-group" style="text-align:center;"><a href="/wiki/Astronomical_chronology" title="Astronomical chronology">Astronomical chronology</a></th>
<td class="navbox-list navbox-even hlist" style="text-align:left;border-left-width:2px;border-left-style:solid;width:100%;padding:0px">
<div style="padding:0em 0.25em">
<ul>
<li><a href="/wiki/Galactic_year" title="Galactic year">Galactic year</a></li>
<li><a href="/wiki/Nuclear_timescale" title="Nuclear timescale">Nuclear timescale</a></li>
<li><a href="/wiki/Precession_(astronomy)" class="mw-redirect" title="Precession (astronomy)">Precession</a></li>
<li><a href="/wiki/Sidereal_time" title="Sidereal time">Sidereal time</a></li>
</ul>
</div>
</td>
</tr>
<tr style="height:2px">
<td colspan="2"></td>
</tr>
<tr>
<th scope="row" class="navbox-group" style="text-align:center;"><a href="/wiki/Unit_of_time" title="Unit of time">Units of time</a></th>
<td class="navbox-list navbox-odd hlist" style="text-align:left;border-left-width:2px;border-left-style:solid;width:100%;padding:0px">
<div style="padding:0em 0.25em">
<ul>
<li><a href="/wiki/Century" title="Century">Century</a></li>
<li><a href="/wiki/Day" title="Day">Day</a></li>
<li><a href="/wiki/Decade" title="Decade">Decade</a></li>
<li><a href="/wiki/Fortnight" title="Fortnight">Fortnight</a></li>
<li><a href="/wiki/Hour" title="Hour">Hour</a></li>
<li><a href="/wiki/Jiffy_(time)" title="Jiffy (time)">Jiffy</a></li>
<li><a href="/wiki/Lustrum" title="Lustrum">Lustrum</a></li>
<li><a href="/wiki/Millennium" title="Millennium">Millennium</a></li>
<li><a href="/wiki/Minute" title="Minute">Minute</a></li>
<li><a href="/wiki/Moment_(time)" title="Moment (time)">Moment</a></li>
<li><a href="/wiki/Month" title="Month">Month</a></li>
<li><a href="/wiki/Paksha" title="Paksha">Paksha</a></li>
<li><a href="/wiki/Saeculum" title="Saeculum">Saeculum</a></li>
<li><a href="/wiki/Second" title="Second">Second</a></li>
<li><a href="/wiki/Shake_(unit)" title="Shake (unit)">Shake</a></li>
<li><a href="/wiki/Tide_(time)" title="Tide (time)">Tide</a></li>
<li><a href="/wiki/Week" title="Week">Week</a></li>
<li><a href="/wiki/Year" title="Year">Year</a></li>
</ul>
</div>
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</tr>
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<th scope="row" class="navbox-group" style="text-align:center;">Related topics</th>
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<div style="padding:0em 0.25em">
<ul>
<li><a href="/wiki/Chronology" title="Chronology">Chronology</a></li>
<li><a href="/wiki/Duration_(philosophy)" title="Duration (philosophy)">Duration</a>
<ul>
<li><a href="/wiki/Duration_(music)" title="Duration (music)">music</a></li>
</ul>
</li>
<li><a href="/wiki/Mental_chronometry" title="Mental chronometry">Mental chronometry</a></li>
<li><a href="/wiki/Metric_time" title="Metric time">Metric time</a></li>
<li><a href="/wiki/System_time" title="System time">System time</a></li>
<li><a href="/wiki/Time_value_of_money" title="Time value of money">Time value of money</a></li>
<li><a href="/wiki/Timekeeper" title="Timekeeper">Timekeeper</a></li>
</ul>
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<div id="Circles_of_latitude_.2F_Meridians" style="font-size:114%"><a href="/wiki/Circle_of_latitude" title="Circle of latitude">Circles of latitude</a> / <a href="/wiki/Meridian_(geography)" title="Meridian (geography)">Meridians</a></div>
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<div style="padding: 2.5em 9em 0em 3em; font-size:80%; margin:0 auto; text-align:left; width:720px;">
<div role="img" style="width: 720px; line-height: 1; text-align: center; background-color: #ffffff; position: relative;"><a href="/wiki/File:Earthmap720x360_grid.jpg" class="image"><img alt="" src="//upload.wikimedia.org/wikipedia/commons/1/1f/Earthmap720x360_grid.jpg" width="720" height="360" data-file-width="720" data-file-height="360" /></a>
<div style="position:absolute; left:66px; top:172px"><b><a href="/wiki/Equator" title="Equator"><font color="#FFFFFF"><font face="Arial Narrow" size="2">Equator</font></font></a></b></div>
<div style="position:absolute; left:66px; top:125.128px"><a href="/wiki/Tropic_of_Cancer" title="Tropic of Cancer"><font color="#FFFFFF"><font face="Arial Narrow" size="2">Tropic of Cancer</font></font></a></div>
<div style="position:absolute; left:66px; top:218.872px"><a href="/wiki/Tropic_of_Capricorn" title="Tropic of Capricorn"><font color="#FFFFFF"><font face="Arial Narrow" size="2">Tropic of Capricorn</font></font></a></div>
<div style="position:absolute; left:66px; top:38.872px"><a href="/wiki/Arctic_Circle" title="Arctic Circle"><font color="#FFFFFF"><font face="Arial Narrow" size="2">Arctic Circle</font></font></a></div>
<div style="position:absolute; left:66px; top:305.128px"><a href="/wiki/Antarctic_Circle" title="Antarctic Circle"><font color="#FFFFFF"><font face="Arial Narrow" size="2">Antarctic Circle</font></font></a></div>
<div style="position:absolute; left:462px; top:172px"><b><a href="/wiki/Equator" title="Equator"><font color="#FFFFFF"><font face="Arial Narrow" size="2">Equator</font></font></a></b></div>
<div style="position:absolute; left:462px; top:125.128px"><a href="/wiki/Tropic_of_Cancer" title="Tropic of Cancer"><font color="#FFFFFF"><font face="Arial Narrow" size="2">Tropic of Cancer</font></font></a></div>
<div style="position:absolute; left:462px; top:218.872px"><a href="/wiki/Tropic_of_Capricorn" title="Tropic of Capricorn"><font color="#FFFFFF"><font face="Arial Narrow" size="2">Tropic of Capricorn</font></font></a></div>
<div style="position:absolute; left:462px; top:38.872px"><a href="/wiki/Arctic_Circle" title="Arctic Circle"><font color="#FFFFFF"><font face="Arial Narrow" size="2">Arctic Circle</font></font></a></div>
<div style="position:absolute; left:462px; top:305.128px"><a href="/wiki/Antarctic_Circle" title="Antarctic Circle"><font color="#FFFFFF"><font face="Arial Narrow" size="2">Antarctic Circle</font></font></a></div>
<div style="position:absolute; left:721.2px; top:172px"><b><a href="/wiki/Equator" title="Equator">Equator</a></b></div>
<div style="position:absolute; left:721.2px; top:125.128px"><a href="/wiki/Tropic_of_Cancer" title="Tropic of Cancer">Tropic of Cancer</a></div>
<div style="position:absolute; left:721.2px; top:218.872px"><a href="/wiki/Tropic_of_Capricorn" title="Tropic of Capricorn">Tropic of Capricorn</a></div>
<div style="position:absolute; left:721.2px; top:38.872px"><a href="/wiki/Arctic_Circle" title="Arctic Circle">Arctic Circle</a></div>
<div style="position:absolute; left:721.2px; top:305.128px"><a href="/wiki/Antarctic_Circle" title="Antarctic Circle">Antarctic Circle</a></div>
<div style="position:absolute; font-size:85%; left:350.4px; top:-11.6px"><b><a href="/wiki/Western_Hemisphere" title="Western Hemisphere">W</a> <strong class="selflink">0°</strong> <a href="/wiki/Eastern_Hemisphere" title="Eastern Hemisphere">E</a></b></div>
<div style="position:absolute; font-size:85%; left:415.2px; top:-11.6px"><a href="/wiki/30th_meridian_east" title="30th meridian east"><font face="Arial Narrow">30°</font></a></div>
<div style="position:absolute; font-size:85%; left:476.4px; top:-11.6px"><a href="/wiki/60th_meridian_east" title="60th meridian east"><font face="Arial Narrow">60°</font></a></div>
<div style="position:absolute; font-size:85%; left:534px; top:-11.6px"><a href="/wiki/90th_meridian_east" title="90th meridian east"><font face="Arial Narrow"><b>90°</b></font></a></div>
<div style="position:absolute; font-size:85%; left:591.6px; top:-11.6px"><a href="/wiki/120th_meridian_east" title="120th meridian east"><font face="Arial Narrow">120°</font></a></div>
<div style="position:absolute; font-size:85%; left:652.8px; top:-11.6px"><a href="/wiki/150th_meridian_east" title="150th meridian east"><font face="Arial Narrow">150°</font></a></div>
<div style="position:absolute; font-size:85%; left:714px; top:-11.6px"><a href="/wiki/180th_meridian" title="180th meridian"><font face="Arial Narrow"><b>180°</b></font></a></div>
<div style="position:absolute; font-size:85%; left:296.4px; top:-11.6px"><a href="/wiki/30th_meridian_west" title="30th meridian west"><font face="Arial Narrow">30°</font></a></div>
<div style="position:absolute; font-size:85%; left:235.2px; top:-11.6px"><a href="/wiki/60th_meridian_west" title="60th meridian west"><font face="Arial Narrow">60°</font></a></div>
<div style="position:absolute; font-size:85%; left:174px; top:-11.6px"><a href="/wiki/90th_meridian_west" title="90th meridian west"><font face="Arial Narrow"><b>90°</b></font></a></div>
<div style="position:absolute; font-size:85%; left:112.8px; top:-11.6px"><a href="/wiki/120th_meridian_west" title="120th meridian west"><font face="Arial Narrow">120°</font></a></div>
<div style="position:absolute; font-size:85%; left:53.4px; top:-11.6px"><a href="/wiki/150th_meridian_west" title="150th meridian west"><font face="Arial Narrow">150°</font></a></div>
<div style="position:absolute; font-size:85%; left:-6px; top:-13.04px"><a href="/wiki/180th_meridian" title="180th meridian"><font face="Arial Narrow"><b>180°</b></font></a></div>
<div style="position:absolute; font-size:85%; left:368.4px; top:-22.4px"><a href="/wiki/5th_meridian_east" title="5th meridian east">5°</a></div>
<div style="position:absolute; font-size:85%; left:386.4px; top:-22.4px"><a href="/wiki/15th_meridian_east" title="15th meridian east">15°</a></div>
<div style="position:absolute; font-size:85%; left:408px; top:-22.4px"><a href="/wiki/25th_meridian_east" title="25th meridian east">25°</a></div>
<div style="position:absolute; font-size:85%; left:426px; top:-22.4px"><a href="/wiki/35th_meridian_east" title="35th meridian east">35°</a></div>
<div style="position:absolute; font-size:85%; left:444px; top:-22.4px"><a href="/wiki/45th_meridian_east" title="45th meridian east">45°</a></div>
<div style="position:absolute; font-size:85%; left:465.6px; top:-22.4px"><a href="/wiki/55th_meridian_east" title="55th meridian east">55°</a></div>
<div style="position:absolute; font-size:85%; left:487.2px; top:-22.4px"><a href="/wiki/65th_meridian_east" title="65th meridian east">65°</a></div>
<div style="position:absolute; font-size:85%; left:505.2px; top:-22.4px"><a href="/wiki/75th_meridian_east" title="75th meridian east">75°</a></div>
<div style="position:absolute; font-size:85%; left:526.8px; top:-22.4px"><a href="/wiki/85th_meridian_east" title="85th meridian east">85°</a></div>
<div style="position:absolute; font-size:85%; left:544.8px; top:-22.4px"><a href="/wiki/95th_meridian_east" title="95th meridian east">95°</a></div>
<div style="position:absolute; font-size:85%; left:562.8px; top:-22.4px"><a href="/wiki/105th_meridian_east" title="105th meridian east">105°</a></div>
<div style="position:absolute; font-size:85%; left:584.4px; top:-22.4px"><a href="/wiki/115th_meridian_east" title="115th meridian east">115°</a></div>
<div style="position:absolute; font-size:85%; left:602.4px; top:-22.4px"><a href="/wiki/125th_meridian_east" title="125th meridian east">125°</a></div>
<div style="position:absolute; font-size:85%; left:624px; top:-22.4px"><a href="/wiki/135th_meridian_east" title="135th meridian east">135°</a></div>
<div style="position:absolute; font-size:85%; left:642px; top:-22.4px"><a href="/wiki/145th_meridian_east" title="145th meridian east">145°</a></div>
<div style="position:absolute; font-size:85%; left:663.6px; top:-22.4px"><a href="/wiki/155th_meridian_east" title="155th meridian east">155°</a></div>
<div style="position:absolute; font-size:85%; left:681.6px; top:-22.4px"><a href="/wiki/165th_meridian_east" title="165th meridian east">165°</a></div>
<div style="position:absolute; font-size:85%; left:703.2px; top:-22.4px"><a href="/wiki/175th_meridian_east" title="175th meridian east">175°</a></div>
<div style="position:absolute; font-size:85%; left:346.8px; top:-22.4px"><a href="/wiki/5th_meridian_west" title="5th meridian west">5°</a></div>
<div style="position:absolute; font-size:85%; left:325.2px; top:-22.4px"><a href="/wiki/15th_meridian_west" title="15th meridian west">15°</a></div>
<div style="position:absolute; font-size:85%; left:307.2px; top:-22.4px"><a href="/wiki/25th_meridian_west" title="25th meridian west">25°</a></div>
<div style="position:absolute; font-size:85%; left:285.6px; top:-22.4px"><a href="/wiki/35th_meridian_west" title="35th meridian west">35°</a></div>
<div style="position:absolute; font-size:85%; left:264px; top:-22.4px"><a href="/wiki/45th_meridian_west" title="45th meridian west">45°</a></div>
<div style="position:absolute; font-size:85%; left:246px; top:-22.4px"><a href="/wiki/55th_meridian_west" title="55th meridian west">55°</a></div>
<div style="position:absolute; font-size:85%; left:224.4px; top:-22.4px"><a href="/wiki/65th_meridian_west" title="65th meridian west">65°</a></div>
<div style="position:absolute; font-size:85%; left:206.4px; top:-22.4px"><a href="/wiki/75th_meridian_west" title="75th meridian west">75°</a></div>
<div style="position:absolute; font-size:85%; left:184.8px; top:-22.4px"><a href="/wiki/85th_meridian_west" title="85th meridian west">85°</a></div>
<div style="position:absolute; font-size:85%; left:166.8px; top:-22.4px"><a href="/wiki/95th_meridian_west" title="95th meridian west">95°</a></div>
<div style="position:absolute; font-size:85%; left:145.2px; top:-22.4px"><a href="/wiki/105th_meridian_west" title="105th meridian west">105°</a></div>
<div style="position:absolute; font-size:85%; left:123.6px; top:-22.4px"><a href="/wiki/115th_meridian_west" title="115th meridian west">115°</a></div>
<div style="position:absolute; font-size:85%; left:102px; top:-22.4px"><a href="/wiki/125th_meridian_west" title="125th meridian west">125°</a></div>
<div style="position:absolute; font-size:85%; left:84px; top:-22.4px"><a href="/wiki/135th_meridian_west" title="135th meridian west">135°</a></div>
<div style="position:absolute; font-size:85%; left:62.4px; top:-22.4px"><a href="/wiki/145th_meridian_west" title="145th meridian west">145°</a></div>
<div style="position:absolute; font-size:85%; left:44.4px; top:-22.4px"><a href="/wiki/155th_meridian_west" title="155th meridian west">155°</a></div>
<div style="position:absolute; font-size:85%; left:22.8px; top:-22.4px"><a href="/wiki/165th_meridian_west" title="165th meridian west">165°</a></div>
<div style="position:absolute; font-size:85%; left:4.8px; top:-22.4px"><a href="/wiki/175th_meridian_west" title="175th meridian west">175°</a></div>
<div style="position:absolute; font-size:85%; left:375.6px; top:-11.6px"><a href="/wiki/10th_meridian_east" title="10th meridian east">10°</a></div>
<div style="position:absolute; font-size:85%; left:397.2px; top:-11.6px"><a href="/wiki/20th_meridian_east" title="20th meridian east">20°</a></div>
<div style="position:absolute; font-size:85%; left:433.2px; top:-11.6px"><a href="/wiki/40th_meridian_east" title="40th meridian east">40°</a></div>
<div style="position:absolute; font-size:85%; left:454.8px; top:-11.6px"><a href="/wiki/50th_meridian_east" title="50th meridian east">50°</a></div>
<div style="position:absolute; font-size:85%; left:494.4px; top:-11.6px"><a href="/wiki/70th_meridian_east" title="70th meridian east">70°</a></div>
<div style="position:absolute; font-size:85%; left:516px; top:-11.6px"><a href="/wiki/80th_meridian_east" title="80th meridian east">80°</a></div>
<div style="position:absolute; font-size:85%; left:552px; top:-11.6px"><a href="/wiki/100th_meridian_east" title="100th meridian east">100°</a></div>
<div style="position:absolute; font-size:85%; left:573.6px; top:-11.6px"><a href="/wiki/110th_meridian_east" title="110th meridian east">110°</a></div>
<div style="position:absolute; font-size:85%; left:613.2px; top:-11.6px"><a href="/wiki/130th_meridian_east" title="130th meridian east">130°</a></div>
<div style="position:absolute; font-size:85%; left:634.8px; top:-11.6px"><a href="/wiki/140th_meridian_east" title="140th meridian east">140°</a></div>
<div style="position:absolute; font-size:85%; left:674.4px; top:-11.6px"><a href="/wiki/160th_meridian_east" title="160th meridian east">160°</a></div>
<div style="position:absolute; font-size:85%; left:692.4px; top:-11.6px"><a href="/wiki/170th_meridian_east" title="170th meridian east">170°</a></div>
<div style="position:absolute; font-size:85%; left:336px; top:-11.6px"><a href="/wiki/10th_meridian_west" title="10th meridian west">10°</a></div>
<div style="position:absolute; font-size:85%; left:318px; top:-11.6px"><a href="/wiki/20th_meridian_west" title="20th meridian west">20°</a></div>
<div style="position:absolute; font-size:85%; left:274.8px; top:-11.6px"><a href="/wiki/40th_meridian_west" title="40th meridian west">40°</a></div>
<div style="position:absolute; font-size:85%; left:253.2px; top:-11.6px"><a href="/wiki/50th_meridian_west" title="50th meridian west">50°</a></div>
<div style="position:absolute; font-size:85%; left:217.2px; top:-11.6px"><a href="/wiki/70th_meridian_west" title="70th meridian west">70°</a></div>
<div style="position:absolute; font-size:85%; left:195.6px; top:-11.6px"><a href="/wiki/80th_meridian_west" title="80th meridian west">80°</a></div>
<div style="position:absolute; font-size:85%; left:152.4px; top:-11.6px"><a href="/wiki/100th_meridian_west" title="100th meridian west">100°</a></div>
<div style="position:absolute; font-size:85%; left:134.4px; top:-11.6px"><a href="/wiki/110th_meridian_west" title="110th meridian west">110°</a></div>
<div style="position:absolute; font-size:85%; left:94.8px; top:-11.6px"><a href="/wiki/130th_meridian_west" title="130th meridian west">130°</a></div>
<div style="position:absolute; font-size:85%; left:73.2px; top:-11.6px"><a href="/wiki/140th_meridian_west" title="140th meridian west">140°</a></div>
<div style="position:absolute; font-size:85%; left:33.6px; top:-11.6px"><a href="/wiki/160th_meridian_west" title="160th meridian west">160°</a></div>
<div style="position:absolute; font-size:85%; left:12px; top:-11.6px"><a href="/wiki/170th_meridian_west" title="170th meridian west">170°</a></div>
<div style="position:absolute; font-size:85%; left:-13.2px; top:175.6px"><b><a href="/wiki/Equator" title="Equator">0°</a></b></div>
<div style="position:absolute; font-size:85%; left:-13.2px; top:154px"><a href="/wiki/10th_parallel_north" title="10th parallel north">10°</a></div>
<div style="position:absolute; font-size:85%; left:-13.2px; top:136px"><a href="/wiki/20th_parallel_north" title="20th parallel north">20°</a></div>
<div style="position:absolute; font-size:85%; left:-13.2px; top:114.4px"><a href="/wiki/30th_parallel_north" title="30th parallel north">30°</a></div>
<div style="position:absolute; font-size:85%; left:-13.2px; top:96.4px"><a href="/wiki/40th_parallel_north" title="40th parallel north">40°</a></div>
<div style="position:absolute; font-size:85%; left:-13.2px; top:74.8px"><a href="/wiki/50th_parallel_north" title="50th parallel north">50°</a></div>
<div style="position:absolute; font-size:85%; left:-13.2px; top:56.8px"><a href="/wiki/60th_parallel_north" title="60th parallel north">60°</a></div>
<div style="position:absolute; font-size:85%; left:-13.2px; top:35.2px"><a href="/wiki/70th_parallel_north" title="70th parallel north">70°</a></div>
<div style="position:absolute; font-size:85%; left:-13.2px; top:13.6px"><a href="/wiki/80th_parallel_north" title="80th parallel north">80°</a></div>
<div style="position:absolute; font-size:85%; left:-13.2px; top:-4.4px"><a href="/wiki/North_Pole" title="North Pole">90°</a></div>
<div style="position:absolute; font-size:85%; left:-13.2px; top:197.2px"><a href="/wiki/10th_parallel_south" title="10th parallel south">10°</a></div>
<div style="position:absolute; font-size:85%; left:-13.2px; top:215.2px"><a href="/wiki/20th_parallel_south" title="20th parallel south">20°</a></div>
<div style="position:absolute; font-size:85%; left:-13.2px; top:236.8px"><a href="/wiki/30th_parallel_south" title="30th parallel south">30°</a></div>