{"id":2298,"date":"2016-09-16T10:43:30","date_gmt":"2016-09-16T08:43:30","guid":{"rendered":"http:\/\/wp.unil.ch\/geoblog\/?p=2298"},"modified":"2024-06-07T15:08:26","modified_gmt":"2024-06-07T13:08:26","slug":"vous-avez-dit-pergelisol","status":"publish","type":"post","link":"https:\/\/wp.unil.ch\/geoblog\/2016\/09\/vous-avez-dit-pergelisol\/","title":{"rendered":"Vous avez dit perg\u00e9lisol ?"},"content":{"rendered":"\n<div class=\"wp-block-buttons is-content-justification-right is-layout-flex wp-container-core-buttons-is-layout-e351d09b wp-block-buttons-is-layout-flex\" style=\"margin-top:0;margin-bottom:0\">\n<div class=\"wp-block-button is-style-outline is-style-outline--1\"><a class=\"wp-block-button__link has-white-color has-accent-3-background-color has-text-color has-background has-link-color has-border-color has-accent-1-border-color has-medium-font-size has-text-align-right has-custom-font-size wp-element-button\" href=\"https:\/\/wp.unil.ch\/geoblog\/category\/travaux-detudiants\/\" style=\"border-width:1px;border-radius:40px;padding-top:var(--wp--preset--spacing--20);padding-right:var(--wp--preset--spacing--30);padding-bottom:var(--wp--preset--spacing--20);padding-left:var(--wp--preset--spacing--30)\"><strong>Travaux d&rsquo;\u00e9tudiant\u00b7es<\/strong><\/a><\/div>\n<\/div>\n\n\n<figure class=\"wp-block-post-featured-image\"><img loading=\"lazy\" decoding=\"async\" width=\"672\" height=\"372\" src=\"https:\/\/wp.unil.ch\/geoblog\/files\/2016\/09\/fotolia97818370-672x372.jpg\" class=\"attachment-post-thumbnail size-post-thumbnail wp-post-image\" alt=\"\" style=\"object-fit:cover;\" \/><\/figure>\n\n\n<p>Le perg\u00e9lisol (<em>vetchna\u00efa merzlota<\/em> en russe, <em>permafrost<\/em> en anglais) repr\u00e9sente un type de sol gel\u00e9 en permanence durant une p\u00e9riode d\u2019une ann\u00e9e au minimum.<\/p>\n\n\n\n<p>On distingue les couches profondes du perg\u00e9lisol de sa partie haute, o\u00f9 se situe son niveau actif&nbsp;qui nous concerne le plus actuellement : la couche sup\u00e9rieure est en effet de plus en plus affect\u00e9e par sa fonte durant les p\u00e9riodes estivales en raison de l\u2019augmentation des temp\u00e9ratures et du rayonnement UV qu\u2019elle emmagasine.<\/p>\n\n\n\n<p>Ce ph\u00e9nom\u00e8ne de d\u00e9gel est d\u00e9sormais une grande pr\u00e9occupation pour les scientifiques et suscite de l\u2019inqui\u00e9tude aupr\u00e8s des gens bien inform\u00e9s : le perg\u00e9lisol renferme en effet une quantit\u00e9 tr\u00e8s importante de dioxyde de carbone et de m\u00e9thane, dont la lib\u00e9ration progressive pourrait avoir l\u2019effet d\u2019une v\u00e9ritable bombe \u00e0 retardement. Pr\u00e8s de 20% de la surface terrestre \u00e9tant affect\u00e9s par le perg\u00e9lisol sur plusieurs continents, il contiendrait en effet selon les estimations l\u2019\u00e9quivalent de 1 700 milliards de tonnes de carbone d\u2019origine v\u00e9g\u00e9tale, accumul\u00e9 depuis la derni\u00e8re glaciation&nbsp;: son d\u00e9gel et la lib\u00e9ration des gaz qu\u2019il encapsule pourraient avoir un impact hors de toute port\u00e9e sur le d\u00e9r\u00e8glement climatique, faisant varier la concentration de GES (ndlr&nbsp;: gaz \u00e0 effet de serre) du simple au triple.<\/p>\n\n\n\n<p>Fait non anecdotique, le dernier rapport d\u2019\u00e9valuation du GIEC ne prenait pas encore en compte l\u2019influence de ce d\u00e9gel dans le changement climatique et les hausses pr\u00e9vues de temp\u00e9rature\u2026<\/p>\n\n\n\n<p><small>Photo : \u00a9 max5128 fotolia.com<\/small><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Le perg\u00e9lisol (vetchna\u00efa merzlota en russe, permafrost en anglais) repr\u00e9sente un type de sol gel\u00e9 en permanence durant une p\u00e9riode d\u2019une ann\u00e9e au minimum. On distingue les couches profondes du perg\u00e9lisol de sa partie haute, o\u00f9 se situe son niveau actif&nbsp;qui nous concerne le plus actuellement : la couche sup\u00e9rieure est en effet de plus [&hellip;]<\/p>\n","protected":false},"author":1001384,"featured_media":2296,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_seopress_robots_primary_cat":"","_seopress_titles_title":"","_seopress_titles_desc":"","_seopress_robots_index":"","footnotes":"","_links_to":"","_links_to_target":""},"categories":[66915,67081,66905,67189],"tags":[],"class_list":{"0":"post-2298","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-grand-nord","8":"category-journee-dun-e-chercheur-e","9":"category-recherche-en-action","10":"category-travaux-detudiants"},"_links":{"self":[{"href":"https:\/\/wp.unil.ch\/geoblog\/wp-json\/wp\/v2\/posts\/2298","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/wp.unil.ch\/geoblog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/wp.unil.ch\/geoblog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/wp.unil.ch\/geoblog\/wp-json\/wp\/v2\/users\/1001384"}],"replies":[{"embeddable":true,"href":"https:\/\/wp.unil.ch\/geoblog\/wp-json\/wp\/v2\/comments?post=2298"}],"version-history":[{"count":2,"href":"https:\/\/wp.unil.ch\/geoblog\/wp-json\/wp\/v2\/posts\/2298\/revisions"}],"predecessor-version":[{"id":11920,"href":"https:\/\/wp.unil.ch\/geoblog\/wp-json\/wp\/v2\/posts\/2298\/revisions\/11920"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/wp.unil.ch\/geoblog\/wp-json\/wp\/v2\/media\/2296"}],"wp:attachment":[{"href":"https:\/\/wp.unil.ch\/geoblog\/wp-json\/wp\/v2\/media?parent=2298"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/wp.unil.ch\/geoblog\/wp-json\/wp\/v2\/categories?post=2298"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/wp.unil.ch\/geoblog\/wp-json\/wp\/v2\/tags?post=2298"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}