Geographical pole: Difference between revisions

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A ”’geographical pole”’ or ”’geographic pole”’ is either of the two points on Earth where its [[axis of rotation]] intersects its surface.<ref>{{cite encyclopedia |title=pole; geographic pole |last1=Kotlyakov |first1=Vladimir |last2=Komarova |first2=Anna |encyclopedia=Elsevier’s dictionary of geography : in English, Russian, French, Spanish and German |date=2006 |publisher=Elsevier |isbn=9780080488783 |page=557 |edition=1st |url=https://books.google.com/books?id=6DhWw_cYLicC&pg=PA557 |access-date=22 June 2015}}</ref> The [[North Pole]] lies in the [[Arctic Ocean]] while the [[South Pole]] is in [[Antarctica]]. North and South poles are also defined for other planets or satellites in the [[Solar System]], with a North pole being on the same side of the [[invariable plane]] as Earth’s North pole.<ref>{{cite journal |last1=Archinal |first1=B. A. |last2=A’Hearn |first2=M. F. |last3=Bowell |first3=E. |last4=Conrad |first4=A. |last5=Consolmagno |first5=G. J. |last6=Courtin |first6=R. |last7=Fukushima |first7=T. |last8=Hestroffer |first8=D. |last9=Hilton |first9=J. L. |last10=Krasinsky |first10=G. A. |last11=Neumann |first11=G. |last12=Oberst |first12=J. |last13=Seidelmann |first13=P. K. |last14=Stooke |first14=P. |last15=Tholen |first15=D. J. |last16=Thomas |first16=P. C. |last17=Williams |first17=I. P. |title=Report of the IAU Working Group on Cartographic Coordinates and Rotational Elements: 2009 |journal=Celestial Mechanics and Dynamical Astronomy |date=February 2011 |volume=109 |issue=2 |pages=101–135 |doi=10.1007/s10569-010-9320-4|bibcode=2011CeMDA.109..101A |s2cid=189842666 }}</ref>

A ”’geographical pole”’ or ”’geographic pole”’ is either of the two points on Earth where its [[axis of rotation]] intersects its surface.<ref>{{cite encyclopedia |title=pole; geographic pole |last1=Kotlyakov |first1=Vladimir |last2=Komarova |first2=Anna |encyclopedia=Elsevier’s dictionary of geography : in English, Russian, French, Spanish and German |date=2006 |publisher=Elsevier |isbn=9780080488783 |page=557 |edition=1st |url=https://books.google.com/books?id=6DhWw_cYLicC&pg=PA557 |access-date=22 June 2015}}</ref> The [[North Pole]] lies in the [[Arctic Ocean]] while the [[South Pole]] is in [[Antarctica]]. North and South poles are also defined for other planets or satellites in the [[Solar System]], with a North pole being on the same side of the [[invariable plane]] as Earth’s North pole.<ref>{{cite journal |last1=Archinal |first1=B. A. |last2=A’Hearn |first2=M. F. |last3=Bowell |first3=E. |last4=Conrad |first4=A. |last5=Consolmagno |first5=G. J. |last6=Courtin |first6=R. |last7=Fukushima |first7=T. |last8=Hestroffer |first8=D. |last9=Hilton |first9=J. L. |last10=Krasinsky |first10=G. A. |last11=Neumann |first11=G. |last12=Oberst |first12=J. |last13=Seidelmann |first13=P. K. |last14=Stooke |first14=P. |last15=Tholen |first15=D. J. |last16=Thomas |first16=P. C. |last17=Williams |first17=I. P. |title=Report of the IAU Working Group on Cartographic Coordinates and Rotational Elements: 2009 |journal=Celestial Mechanics and Dynamical Astronomy |date=February 2011 |volume=109 |issue=2 |pages=101–135 |doi=10.1007/s10569-010-9320-4|bibcode=2011CeMDA.109..101A |s2cid=189842666 }}</ref>

Relative to Earth’s surface, the geographic poles move by a few metres over periods of a few years.<ref>{{cite web|last=Lovett |first=Richard A. |url=http://www.scientificamerican.com/article/climate-change-has-shifted-location-north-south-poles/ |title=Climate change has shifted the locations of Earth’s North and South Poles |publisher=Scientific American |date=14 May 2013 |access-date=6 January 2019}}</ref> This is a combination of [[Chandler wobble]], a free oscillation with a period of about 433 days; an annual motion responding to seasonal movements of air and water masses; and an irregular drift towards the 80th west [[meridian (geography)|meridian]].<ref>{{cite web |title=Polar motion |url=https://www.iers.org/IERS/EN/Science/EarthRotation/PolarMotion.html |website=International Earth Rotation and Reference Systems Service |publisher=Federal Agency for Cartography and Geodesy |year=2013 |access-date=22 October 2020}}</ref> As [[cartography]] requires exact and unchanging coordinates, the averaged{{citation needed|date=May 2014}} locations of geographical poles are taken as fixed ”cartographic poles” and become the points where the body’s [[great circle]]s of [[longitude]] intersect.

Relative to Earth’s surface, the geographic poles move by a few metres over periods of a few years.<ref>{{cite web|last=Lovett |first=Richard A. |url=http://www.scientificamerican.com/article/climate-change-has-shifted-location-north-south-poles/ |title=Climate change has shifted the locations of Earth’s North and South Poles |publisher=Scientific American |date=14 May 2013 |access-date=6 January 2019}}</ref> This is a combination of [[Chandler wobble]], a free oscillation with a period of about 433 days; an annual motion responding to seasonal movements of air and water masses; and an irregular drift towards the 80th west [[meridian (geography)|meridian]].<ref>{{cite web |title=Polar motion |url=https://www.iers.org/IERS/EN/Science/EarthRotation/PolarMotion.html |website=International Earth Rotation and Reference Systems Service |publisher=Federal Agency for Cartography and Geodesy |year=2013 |access-date=22 October 2020}}</ref> As [[cartography]] exact and unchanging coordinates, the {{citation needed|date=May 2014}} locations of geographical poles are taken as fixed ”cartographic poles” the points where the body’s [[great circle]]s of [[longitude]] intersect.

==See also==

==See also==


Latest revision as of 20:53, 15 September 2025

Points on a rotating astronomical body where the axis of rotation intersects the surface

A geographical axis of rotation A (green), and showing the north geographical pole A1, and south geographical pole A2; also showing a magnetic field and the magnetic axis of rotation B (blue), and the north magnetic pole B1, and south magnetic pole B2.

A geographical pole or geographic pole is either of the two points on Earth where its axis of rotation intersects its surface.[1] The North Pole lies in the Arctic Ocean while the South Pole is in Antarctica. North and South poles are also defined for other planets or satellites in the Solar System, with a North pole being on the same side of the invariable plane as Earth’s North pole.[2]

Relative to Earth’s surface, the geographic poles move by a few metres over periods of a few years.[3] This is a combination of Chandler wobble, a free oscillation with a period of about 433 days; an annual motion responding to seasonal movements of air and water masses; and an irregular drift towards the 80th west meridian.[4] As cartography and geodesy require exact and unchanging coordinates, the average or nominal[citation needed] locations of geographical poles are taken as fixed cartographic poles or geodetic poles, the points where the body’s great circles of longitude intersect; in practice this is achieved by keeping latitude values of survey markers fixed and accounting for time variations in terms of Earth orientation parameters.

  1. ^ Kotlyakov, Vladimir; Komarova, Anna (2006). “pole; geographic pole”. Elsevier’s dictionary of geography : in English, Russian, French, Spanish and German (1st ed.). Elsevier. p. 557. ISBN 9780080488783. Retrieved 22 June 2015.
  2. ^ 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. (February 2011). “Report of the IAU Working Group on Cartographic Coordinates and Rotational Elements: 2009”. Celestial Mechanics and Dynamical Astronomy. 109 (2): 101–135. Bibcode:2011CeMDA.109..101A. doi:10.1007/s10569-010-9320-4. S2CID 189842666.
  3. ^ Lovett, Richard A. (14 May 2013). “Climate change has shifted the locations of Earth’s North and South Poles”. Scientific American. Retrieved 6 January 2019.
  4. ^ “Polar motion”. International Earth Rotation and Reference Systems Service. Federal Agency for Cartography and Geodesy. 2013. Retrieved 22 October 2020.

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