{"id":146,"date":"2005-04-22T13:19:06","date_gmt":"2005-04-22T17:19:06","guid":{"rendered":"\/?p=146"},"modified":"2009-06-04T08:43:30","modified_gmt":"2009-06-04T13:43:30","slug":"retreating-glacier-fronts-on-the-antarctic-peninsula-over-the-past-half-century","status":"publish","type":"post","link":"https:\/\/www.realclimate.org\/index.php\/archives\/2005\/04\/retreating-glacier-fronts-on-the-antarctic-peninsula-over-the-past-half-century\/","title":{"rendered":"Retreating Glacier Fronts on the Antarctic Peninsula over the Past Half-Century Recul du Front des Glaciers de la P\u00e9ninsule Antarctique au cours des 50 derni\u00e8res ann\u00e9es<\/lang_fr>"},"content":{"rendered":"
\n

Guest commentary by David Vaughan<\/small><\/p>\n

<\/a> The recent retreat of ice shelves on the Antarctic Peninsula has been widely attributed to warming atmospheric temperatures. There is, however, little published work describing the response of glacier margin positions to this regional climate change. In the paper Retreating Glacier Fronts on the Antarctic Peninsula over the Past Half-Century<\/a> published this week in Science<\/i>, we presented new data describing trends in 244 marine glacier fronts on the Antarctic Peninsula over the last 50 years. The data come from matching archives of over 2000 aerial photographs of the Antarctic Peninsula to satellite images, and represent about three years of work by Alison Cook. The work was carried out at British Antarctic Survey, but was funded by the US Geological Survey, as part of a larger programme to map change in the coastline of all Antarctica.<\/p>\n

<\/p>\n

Analysis of the data reveals that 87% of glaciers have retreated (click on the image for a more detailed figure) and that the change from advance to retreat has occurred progressively with latitude. In 1950s only the most northerly glaciers appeared to be retreating, but a transition from advance to retreat appeared to move down the Antarctic Peninsula over a period of about 10 to 20 years, broadly in line with what we would expect if this was a consequence of the warming that has been measured in this area. However, there are features of the pattern of change that we find difficult to explain by atmospheric warming alone. In particular, there was a period in the late-1980s and early-1990s when retreat slowed down along most of the coast, and we don’t see any cause for this in the temperature records – so there may be some other factors at work, perhaps ocean temperature.<\/p>\n

The retreat of these glaciers in itself will have a negligible effect on sea level, since most of the ice that has retreated was in the water already. However, if as a consequence of shortening, the glaciers are also flowing faster, then we would be seeing another (small) contribution to sea level rise. This is the next line of work and we will report in the near future.<\/p>\n

Reference: Retreating Glacier Fronts on the Antarctic Peninsula over the Past Half-Century<\/a> A. J. Cook, A. J. Fox, D. G. Vaughan, J. G. Ferrigno, Science, Vol 308, Issue 5721, 541-544 , 22 April 2005 [DOI: 10.1126\/science.1104235]<\/p>\n

See also the earlier RealClimate post on Antarctic temperature change<\/a>.<\/p>\n

Note: <\/i> This article (and “RealClimate.org”) were discussed in a segment “Climate Change Update”<\/a> on NPR’s “Science Friday” earlier this afternoon (audio link available here<\/a>).<\/p>\n

Commentaire invit\u00e9 par David Vaughan<\/small><\/p>\n

<\/a> Le recul r\u00e9cent des plate-formes glaciaires de la P\u00e9ninsule Antarctique a \u00e9t\u00e9 largement attribu\u00e9 au r\u00e9chauffement des t\u00e9mp\u00e9ratures atmosph\u00e9riques. Cependant, peu de travaux se sont int\u00e9ress\u00e9s a la r\u00e9ponse des positions de la large des glaciers a ce changement climatique r\u00e9gional. Dans l’article Retreating Glacier Fronts on the Antarctic Peninsula over the Past Half-Century<\/a> publi\u00e9 cette semaine dans Science<\/i>, nous avons pr\u00e9sent\u00e9 de nouvelles donn\u00e9es qui d\u00e9crivent les tendances de 244 fronts de glaciers marins de la P\u00e9ninsule Antarctique au cours des 50 dernieres ann\u00e9es. Les donn\u00e9es proviennent de plus 2000 photographies a\u00e9riennes et images satellites de la P\u00e9ninsule Antarctique, et repr\u00e9sentent plus de trois ann\u00e9es de travail par Alison Cook. Ce travail a \u00e9t\u00e9 effectu\u00e9 au British Antarctic Survey, mais a \u00e9t\u00e9 financ\u00e9 par l’US Geological Survey, dans le cadre plus g\u00e9n\u00e9ral d’un programme de cartographie des changements de la cote Antarctique.<\/p>\n

L’analyse de ces donn\u00e9es montre que 87% des glaciers ont recul\u00e9 (cliquer sur l’image pour plus de d\u00e9tails) et que ce changement de l’avance au recul s’est produit progressivement en corr\u00e9lation avec la latitude. Dans les ann\u00e9es 1950, seuls les glaciers les plus septentrionaux apparaissaient en recul, mais une transition de l’avance des glaciers a un recul a progressivement migr\u00e9 vers le Sud de la Peninsule Antarctique au cours d’une p\u00e9riode d’environ 10 a 20 ans, en accord avec l’hypothese que ces mesures refletent le r\u00e9chauffement mesur\u00e9 dans cette zone. N\u00e9anmoins, certaines caract\u00e9ristiques des changements sont difficilement attribuables au seul r\u00e9chauffement atmosph\u00e9rique. En particulier, au cours de la p\u00e9riode allant de la fin des ann\u00e9es 1980 au d\u00e9but des ann\u00e9es 1990, le recul s’est g\u00e9n\u00e9ralement ralenti, sans qu’il n’y ait de changement associ\u00e9 dans les enregistrements de temp\u00e9rature – observation impliquant que d’autres facteurs sont \u00e9galement en jeu comme peut etre la temp\u00e9rature de l’oc\u00e9an.<\/p>\n

Le recul de ces glaciers aura un effet n\u00e9gligeable sur le niveau marin global, comme la plus grande partie de la glace qui a recul\u00e9 \u00e9tait d\u00e9ja dans l’eau. Cependant, si en r\u00e9ponse au raccourcissement des glaciers ceux-ci acc\u00e9lerent leur vitesse de progression, alors ceci impliquerait une (petite) hausse du niveau marin. Cette suggestion est ce que nous \u00e9tudions actuellement, et nous la documenterons prochainement.<\/p>\n

R\u00e9f\u00e9rence: Retreating Glacier Fronts on the Antarctic Peninsula over the Past Half-Century<\/a> A. J. Cook, A. J. Fox, D. G. Vaughan, J. G. Ferrigno, Science, Vol 308, Issue 5721, 541-544 , 22 April 2005 [DOI: 10.1126\/science.1104235]<\/p>\n

Voir \u00e9galement RealClimate post on Antarctic temperature change<\/a>.<\/p>\n

Note: <\/i> Cet article (et”RealClimate.org”) ont \u00e9t\u00e9 discut\u00e9s “Climate Change Update”<\/a> sur NPR’s “Science Friday” (en anglais: audio ici<\/a>).
\nLe Monde pr\u00e9sente \u00e9galement un article sur ce travail : ici<\/a>, ainsi que Le Nouvel Observateur : ici<\/a>.
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Guest commentary by David Vaughan The recent retreat of ice shelves on the Antarctic Peninsula has been widely attributed to warming atmospheric temperatures. There is, however, little published work describing the response of glacier margin positions to this regional climate change. In the paper Retreating Glacier Fronts on the Antarctic Peninsula over the Past Half-Century […]<\/p>\n","protected":false},"author":12,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_exactmetrics_skip_tracking":false,"_exactmetrics_sitenote_active":false,"_exactmetrics_sitenote_note":"","_exactmetrics_sitenote_category":0,"_genesis_hide_title":false,"_genesis_hide_breadcrumbs":false,"_genesis_hide_singular_image":false,"_genesis_hide_footer_widgets":false,"_genesis_custom_body_class":"","_genesis_custom_post_class":"","_genesis_layout":"","footnotes":""},"categories":[12,1],"tags":[],"class_list":{"0":"post-146","1":"post","2":"type-post","3":"status-publish","4":"format-standard","6":"category-arctic-and-antarctic","7":"category-climate-science","8":"entry"},"aioseo_notices":[],"post_mailing_queue_ids":[],"_links":{"self":[{"href":"https:\/\/www.realclimate.org\/index.php\/wp-json\/wp\/v2\/posts\/146","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.realclimate.org\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.realclimate.org\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.realclimate.org\/index.php\/wp-json\/wp\/v2\/users\/12"}],"replies":[{"embeddable":true,"href":"https:\/\/www.realclimate.org\/index.php\/wp-json\/wp\/v2\/comments?post=146"}],"version-history":[{"count":0,"href":"https:\/\/www.realclimate.org\/index.php\/wp-json\/wp\/v2\/posts\/146\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.realclimate.org\/index.php\/wp-json\/wp\/v2\/media?parent=146"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.realclimate.org\/index.php\/wp-json\/wp\/v2\/categories?post=146"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.realclimate.org\/index.php\/wp-json\/wp\/v2\/tags?post=146"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}