{"id":18000,"date":"2019-01-23T07:00:16","date_gmt":"2019-01-23T06:00:16","guid":{"rendered":"https:\/\/www.laterredufutur.com\/accueil\/?p=18000"},"modified":"2019-01-22T21:28:32","modified_gmt":"2019-01-22T20:28:32","slug":"yellowstone-a-engendre-deux-super-eruptions-qui-ont-modifie-le-climat-mondial","status":"publish","type":"post","link":"https:\/\/www.laterredufutur.com\/accueil\/yellowstone-a-engendre-deux-super-eruptions-qui-ont-modifie-le-climat-mondial\/","title":{"rendered":"Yellowstone a engendr\u00e9 deux super-\u00e9ruptions qui ont modifi\u00e9 le climat mondial"},"content":{"rendered":"<div class=\"1665f18d14f35dd9e7566e1a8ac9a3e9\" data-index=\"1\" style=\"float: none; margin:10px 0 10px 0; text-align:center;\">\n<script async src=\"https:\/\/pagead2.googlesyndication.com\/pagead\/js\/adsbygoogle.js\"><\/script>\r\n<ins class=\"adsbygoogle\"\r\n     style=\"display:block; text-align:center;\"\r\n     data-ad-layout=\"in-article\"\r\n     data-ad-format=\"fluid\"\r\n     data-ad-client=\"ca-pub-2860849627502538\"\r\n     data-ad-slot=\"3019501113\"><\/ins>\r\n<script>\r\n     (adsbygoogle = window.adsbygoogle || []).push({});\r\n<\/script>\n<\/div>\n<p>Une nouvelle recherche g\u00e9ologique de la derni\u00e8re \u00e9ruption catastrophique du supervolcan de Yellowstone est en train de r\u00e9\u00e9crire<strong> l&rsquo;histoire de ce qui s&rsquo;est pass\u00e9 il y a 630 000 ans<\/strong> et de son incidence sur le climat de la Terre. Cette \u00e9ruption a form\u00e9 la vaste caldeira de Yellowstone observ\u00e9e aujourd&rsquo;hui, la deuxi\u00e8me en importance sur Terre.<\/p>\n<p>Deux couches de cendres volcaniques portant l&#8217;empreinte chimique unique de la plus r\u00e9cente super-\u00e9ruption de Yellowstone ont \u00e9t\u00e9 d\u00e9couvertes dans des s\u00e9diments de fonds marins dans le bassin de Santa Barbara, au large de la c\u00f4te sud de la Californie. Ces couches de cendres, ou t\u00e9phra, sont prises en sandwich parmi des s\u00e9diments qui contiennent un enregistrement remarquablement d\u00e9taill\u00e9 du changement oc\u00e9anique et climatique. Ensemble, cendres et s\u00e9diments r\u00e9v\u00e8lent que la derni\u00e8re \u00e9ruption n\u2019est pas un \u00e9v\u00e9nement isol\u00e9, mais deux \u00e9ruptions tr\u00e8s rapproch\u00e9es qui freinent une tendance naturelle au r\u00e9chauffement de la plan\u00e8te qui a finalement conduit la plan\u00e8te \u00e0 sortir d\u2019une importante glaciation.<\/p>\n<p>\u00ab\u00a0<strong>Nous avons d\u00e9couvert ici qu&rsquo;il y avait eu deux super-\u00e9ruptions formant des cendres, \u00e0 170 ans l&rsquo;une de l&rsquo;autre, et chacune refroidissant l&rsquo;oc\u00e9an d&rsquo;environ 3 degr\u00e9s Celsius<\/strong>\u00ab\u00a0, a d\u00e9clar\u00e9 le g\u00e9ologue de l&rsquo;UC Santa Barbara, Jim Kennett. La sp\u00e9cificit\u00e9 de d\u00e9tecter les \u00e9ruptions s\u00e9par\u00e9es et leurs effets sur le climat est due \u00e0 plusieurs conditions sp\u00e9ciales rencontr\u00e9es dans le bassin de Santa Barbara, a d\u00e9clar\u00e9 Kennett.<\/p>\n<p>L&rsquo;une des conditions est l&rsquo;apport r\u00e9gulier de s\u00e9diments dans le bassin \u00e0 partir de la terre &#8211; environ un millim\u00e8tre par an. Ensuite, il y a l&rsquo;oc\u00e9an hautement productif dans la r\u00e9gion, aliment\u00e9 par les nutriments ascendants de l&rsquo;oc\u00e9an profond. Cela a produit de minuscules coquilles de foraminif\u00e8res qui ont coul\u00e9 jusqu&rsquo;au fond de la mer o\u00f9 elles ont \u00e9t\u00e9 enterr\u00e9es et conserv\u00e9es dans les s\u00e9diments. Ces coquilles contiennent des isotopes d&rsquo;oxyg\u00e8ne d\u00e9pendant de la temp\u00e9rature qui r\u00e9v\u00e8lent les temp\u00e9ratures de surface de la mer dans lesquelles ils vivaient.<\/p><div class=\"1665f18d14f35dd9e7566e1a8ac9a3e9\" data-index=\"2\" style=\"float: none; margin:10px 0 10px 0; text-align:center;\">\n<script async src=\"https:\/\/pagead2.googlesyndication.com\/pagead\/js\/adsbygoogle.js\"><\/script>\r\n<ins class=\"adsbygoogle\"\r\n     style=\"display:block; text-align:center;\"\r\n     data-ad-layout=\"in-article\"\r\n     data-ad-format=\"fluid\"\r\n     data-ad-client=\"ca-pub-2860849627502538\"\r\n     data-ad-slot=\"3019501113\"><\/ins>\r\n<script>\r\n     (adsbygoogle = window.adsbygoogle || []).push({});\r\n<\/script>\n<\/div>\n\n<p>En comparant les donn\u00e9es sur les cendres volcaniques aux donn\u00e9es climatiques des foraminif\u00e8res, il est \u00e9vident que ces deux \u00e9ruptions ont provoqu\u00e9 des hivers volcaniques distincts &#8211; c\u2019est \u00e0 ce moment que les \u00e9missions de cendres et de dioxyde de soufre volcanique r\u00e9duisent cette quantit\u00e9 de lumi\u00e8re atteignant la surface de la Terre et entra\u00eenent un refroidissement temporaire. .Ces ph\u00e9nom\u00e8nes de refroidissement se sont produits \u00e0 un moment particuli\u00e8rement sensible, alors que le climat mondial se r\u00e9chauffait apr\u00e8s une p\u00e9riode glaciaire et \u00e9tait facilement perturb\u00e9 par de tels \u00e9v\u00e9nements.<\/p>\n<p>Kennett et ses coll\u00e8gues ont d\u00e9couvert que le d\u00e9but des \u00e9v\u00e9nements de refroidissement global \u00e9tait brutal et co\u00efncidait pr\u00e9cis\u00e9ment avec le moment des \u00e9ruptions super-volcaniques, la premi\u00e8re observation de ce type.<\/p>\n<p>Mais \u00e0 chaque fois, le refroidissement a dur\u00e9 plus longtemps que pr\u00e9vu, selon de simples mod\u00e8les climatiques, a-t-il d\u00e9clar\u00e9. \u00abNous constatons un refroidissement plan\u00e9taire d&rsquo;ampleur et de dur\u00e9e suffisantes pour que d&rsquo;autres r\u00e9troactions soient impliqu\u00e9es.\u00bb Ces r\u00e9troactions pouvaient inclure une couverture neigeuse et de la banquise r\u00e9fl\u00e9chissant la lumi\u00e8re du soleil ou un changement de la circulation oc\u00e9anique qui refroidirait la plan\u00e8te plus longtemps.<\/p>\n<p>\u00abC\u2019\u00e9tait une chose capricieuse mais heureuse, a d\u00e9clar\u00e9 Kennett \u00e0 propos du moment des \u00e9ruptions. \u00ab\u00a0Si ces \u00e9ruptions s&rsquo;\u00e9taient produites avec un autre climat, nous n&rsquo;aurions peut-\u00eatre pas d\u00e9tect\u00e9 les cons\u00e9quences climatiques, car les \u00e9pisodes de refroidissement n&rsquo;auraient pas dur\u00e9 aussi longtemps.\u00a0\u00bb<\/p>\n<p>Adaptation <a href=\"https:\/\/www.laterredufutur.com\/accueil\/\">La Terre du Futur<\/a><\/p>\n<p>source :&nbsp;<a href=\"https:\/\/www.heritagedaily.com\/2017\/10\/yellowstone-spawned-twin-super-eruptions-altered-global-climate\/117192\" target=\"_blank\" rel=\"noopener\">https:\/\/www.heritagedaily.com\/<\/a><\/p>\n<p class=\"bawpvc-ajax-counter\" data-id=\"18000\">(1903)<\/p>\n<!--CusAds0-->\n<div style=\"font-size: 0px; height: 0px; line-height: 0px; margin: 0; padding: 0; clear: both;\"><\/div>","protected":false},"excerpt":{"rendered":"<p>Une nouvelle recherche g\u00e9ologique de la derni\u00e8re \u00e9ruption catastrophique du supervolcan de Yellowstone est en train de r\u00e9\u00e9crire l&rsquo;histoire de&#8230;<\/p>\n","protected":false},"author":1,"featured_media":18001,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_exactmetrics_skip_tracking":false,"_exactmetrics_sitenote_active":false,"_exactmetrics_sitenote_note":"","_exactmetrics_sitenote_category":0,"ngg_post_thumbnail":0,"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"Yellowstone a engendr\u00e9 deux super-\u00e9ruptions qui ont modifi\u00e9 le climat mondial @laterredufutur.com","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[19],"tags":[2264,377,374,5574,6961,48,105],"class_list":["post-18000","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-seismes-et-volcans","tag-caldeira","tag-cendres","tag-eruption","tag-super-eruption","tag-tephra","tag-volcan","tag-yellowstone","wpcat-19-id"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2019\/01\/yellowstone-super-eruption.jpg?fit=1200%2C631&ssl=1","jetpack_shortlink":"https:\/\/wp.me\/p631RN-4Gk","jetpack-related-posts":[{"id":15969,"url":"https:\/\/www.laterredufutur.com\/accueil\/le-super-volcan-du-yellowstone-en-bref\/","url_meta":{"origin":18000,"position":0},"title":"Le super-volcan du Yellowstone en bref","author":"Admin","date":"21 octobre 2017","format":false,"excerpt":"Le super-volcan du parc am\u00e9ricain du Yellowstone pourrait se r\u00e9veiller un peu plus t\u00f4t que pr\u00e9vu et plonger la Terre dans un hiver de plusieurs mois. Mais ceci n'a rien d'alarmant car il faut r\u00e9ellement lire la nature r\u00e9elle de cette \u00e9tude dans les termes suivants : Les scientifiques ont\u2026","rel":"","context":"Dans &quot;Seismes\/Volcans&quot;","block_context":{"text":"Seismes\/Volcans","link":"https:\/\/www.laterredufutur.com\/accueil\/sujets\/seismes-et-volcans\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2016\/03\/yellowstone.jpg?fit=700%2C371&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2016\/03\/yellowstone.jpg?fit=700%2C371&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2016\/03\/yellowstone.jpg?fit=700%2C371&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2016\/03\/yellowstone.jpg?fit=700%2C371&ssl=1&resize=700%2C400 2x"},"classes":[]},{"id":20329,"url":"https:\/\/www.laterredufutur.com\/accueil\/volcan-de-yellowstone-un-scientifique-de-lusgs-a-admis-quune-eruption-massive-est-possible\/","url_meta":{"origin":18000,"position":1},"title":"Volcan de Yellowstone: Un scientifique de l&rsquo;USGS a admis qu&rsquo;une \u00ab\u00a0 \u00e9ruption massive est possible \u00a0\u00bb","author":"Admin","date":"22 janvier 2020","format":false,"excerpt":"Une super-\u00e9ruption du Yellowstone dans le futur est \u00abpossible\u00bb \u00e0 tout moment, a admis un scientifique de l'USGS \u00e9tudiant le volcan lors d'une s\u00e9ance de questions et r\u00e9ponses avec le public. La caldeira de Yellowstone est d\u00e9sign\u00e9e de mani\u00e8re effrayante comme un super-volcan en raison de sa capacit\u00e9 \u00e0 infliger\u2026","rel":"","context":"Dans &quot;Seismes\/Volcans&quot;","block_context":{"text":"Seismes\/Volcans","link":"https:\/\/www.laterredufutur.com\/accueil\/sujets\/seismes-et-volcans\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2019\/01\/yellowstone-super-eruption.jpg?fit=1200%2C631&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2019\/01\/yellowstone-super-eruption.jpg?fit=1200%2C631&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2019\/01\/yellowstone-super-eruption.jpg?fit=1200%2C631&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2019\/01\/yellowstone-super-eruption.jpg?fit=1200%2C631&ssl=1&resize=700%2C400 2x, https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2019\/01\/yellowstone-super-eruption.jpg?fit=1200%2C631&ssl=1&resize=1050%2C600 3x"},"classes":[]},{"id":1702,"url":"https:\/\/www.laterredufutur.com\/accueil\/la-caldera-du-yellowstone\/","url_meta":{"origin":18000,"position":2},"title":"La Caldeira du Yellowstone","author":"Admin","date":"17 d\u00e9cembre 2013","format":false,"excerpt":"Il n'y a pas que les impacts d'ast\u00e9ro\u00efdes qui peuvent provoquer des extinctions de masse, comme celle qui a emport\u00e9 les dinosaures. Les chercheurs savent depuis longtemps que certaines sont associ\u00e9es \u00e0 des \u00e9pisodes de volcanisme tr\u00e8s intense. Mais on ne comprenait pas bien comment ces \u00e9ruptions \u00e0 grande \u00e9chelle\u2026","rel":"","context":"Dans &quot;Seismes\/Volcans&quot;","block_context":{"text":"Seismes\/Volcans","link":"https:\/\/www.laterredufutur.com\/accueil\/sujets\/seismes-et-volcans\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2015\/04\/chambre-magmatique-yellowstone.png?fit=600%2C332&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2015\/04\/chambre-magmatique-yellowstone.png?fit=600%2C332&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2015\/04\/chambre-magmatique-yellowstone.png?fit=600%2C332&ssl=1&resize=525%2C300 1.5x"},"classes":[]},{"id":21766,"url":"https:\/\/www.laterredufutur.com\/accueil\/leruption-recemment-decouverte-du-yellowstone-est-lune-des-5-eruptions-les-plus-puissantes-de-tous-les-temps\/","url_meta":{"origin":18000,"position":3},"title":"L&rsquo;\u00e9ruption r\u00e9cemment d\u00e9couverte du Yellowstone est l&rsquo;une des \u00ab\u00a05 \u00e9ruptions les plus puissantes de tous les temps\u00a0\u00bb","author":"Admin","date":"28 d\u00e9cembre 2020","format":false,"excerpt":"C'est l'une des deux \u00absuper\u00e9ruptions\u00bb r\u00e9cemment d\u00e9tect\u00e9es qui ont secou\u00e9 l'Am\u00e9rique du Nord (et le monde) il y a 9 millions d'ann\u00e9es. Sous les geysers pittoresques et les sources chaudes aux couleurs arc-en-ciel du parc national de Yellowstone se cache l'un des volcans les plus destructeurs de la plan\u00e8te. Le\u2026","rel":"","context":"Dans &quot;Seismes\/Volcans&quot;","block_context":{"text":"Seismes\/Volcans","link":"https:\/\/www.laterredufutur.com\/accueil\/sujets\/seismes-et-volcans\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2019\/01\/yellowstone-super-eruption.jpg?fit=1200%2C631&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2019\/01\/yellowstone-super-eruption.jpg?fit=1200%2C631&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2019\/01\/yellowstone-super-eruption.jpg?fit=1200%2C631&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2019\/01\/yellowstone-super-eruption.jpg?fit=1200%2C631&ssl=1&resize=700%2C400 2x, https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2019\/01\/yellowstone-super-eruption.jpg?fit=1200%2C631&ssl=1&resize=1050%2C600 3x"},"classes":[]},{"id":6121,"url":"https:\/\/www.laterredufutur.com\/accueil\/confirmation-dune-chambre-magmatique-monumentale-sous-le-yellowstone\/","url_meta":{"origin":18000,"position":4},"title":"Confirmation d&rsquo;une chambre magmatique monumentale sous le Yellowstone","author":"Admin","date":"24 avril 2015","format":false,"excerpt":"Un papier vient d'\u00eatre publi\u00e9 dans la revue Science qui confirme que la chambre magmatique sous le Yellowstone est gigantesque. Un gigantesque r\u00e9servoir de magma a \u00e9t\u00e9 d\u00e9couvert et analys\u00e9 sous le super-volcan de Yellowstone aux Etats-Unis, par une \u00e9quipe de vulcanologues qui publie sa d\u00e9couverte dans la revue Science.\u2026","rel":"","context":"Dans &quot;Seismes\/Volcans&quot;","block_context":{"text":"Seismes\/Volcans","link":"https:\/\/www.laterredufutur.com\/accueil\/sujets\/seismes-et-volcans\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2015\/04\/chambre-magmatique-yellowstone.png?fit=600%2C332&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2015\/04\/chambre-magmatique-yellowstone.png?fit=600%2C332&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2015\/04\/chambre-magmatique-yellowstone.png?fit=600%2C332&ssl=1&resize=525%2C300 1.5x"},"classes":[]},{"id":2483,"url":"https:\/\/www.laterredufutur.com\/accueil\/le-plus-grand-cataclysme-que-lhumanite-a-connu\/","url_meta":{"origin":18000,"position":5},"title":"Le Plus Grand Cataclysme que l&rsquo;Humanit\u00e9 a connu","author":"Admin","date":"5 mars 2015","format":false,"excerpt":"Le Plus Grand Cataclysme que l'Humanit\u00e9 a connu se nomme dans le plus grand volcan et le plus dangereux du monde. M\u00eame le Yellowstone n'a jamais \u00e9ject\u00e9 autant de cendres dans l'atmosph\u00e8re. Voyez ce qui s'est pass\u00e9 il y a 75000 ans de \u00e7a, quand l'Humanit\u00e9 a failli dispara\u00eetre compl\u00e8tement\u2026","rel":"","context":"Dans &quot;Seismes\/Volcans&quot;","block_context":{"text":"Seismes\/Volcans","link":"https:\/\/www.laterredufutur.com\/accueil\/sujets\/seismes-et-volcans\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.laterredufutur.com\/wordpress\/wp-content\/uploads\/2011\/09\/toba.jpg?resize=350%2C200","width":350,"height":200},"classes":[]}],"jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/posts\/18000","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/comments?post=18000"}],"version-history":[{"count":3,"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/posts\/18000\/revisions"}],"predecessor-version":[{"id":18004,"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/posts\/18000\/revisions\/18004"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/media\/18001"}],"wp:attachment":[{"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/media?parent=18000"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/categories?post=18000"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/tags?post=18000"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}