{"id":4566,"date":"2008-08-22T16:03:31","date_gmt":"2008-08-22T14:03:31","guid":{"rendered":"http:\/\/www.laterredufutur.com\/accueil1\/?p=4566"},"modified":"2015-04-13T16:05:11","modified_gmt":"2015-04-13T14:05:11","slug":"une-catastrophe-ecologique-provoquee-par-des-volcans-sous-marins","status":"publish","type":"post","link":"https:\/\/www.laterredufutur.com\/accueil\/une-catastrophe-ecologique-provoquee-par-des-volcans-sous-marins\/","title":{"rendered":"Une catastrophe \u00e9cologique provoqu\u00e9e par des volcans sous-marins"},"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 align=\"justify\"><span style=\"font-size: small;\">Par une r\u00e9action en cha\u00eene, des \u00e9ruptions volcaniques sous-marines ont provoqu\u00e9 la disparition de l&rsquo;oxyg\u00e8ne dissous dans les oc\u00e9ans, entra\u00eenant ainsi une extinction massive de plusieurs esp\u00e8ces marines aussi bien animales que v\u00e9g\u00e9tales. L&rsquo;\u00e9tude de cette extinction pourrait nous aider \u00e0 mieux comprendre les interactions entre les oc\u00e9ans et l&rsquo;atmosph\u00e8re, en particulier dans le contexte d&rsquo;un r\u00e9chauffement climatique.<\/span><\/p>\n<p align=\"justify\"><span style=\"font-size: small;\">Il y a 93,5 millions d&rsquo;ann\u00e9es, \u00e0 l&rsquo;\u00e9poque o\u00f9 les dinosaures r\u00e9gnaient en ma\u00eetres sur la terre ferme, est survenue une extinction des esp\u00e8ces marines dont on ignorait jusqu&rsquo;\u00e0 maintenant les causes exactes.<\/span><\/p>\n<p align=\"justify\"><span style=\"font-size: small;\">En \u00e9tudiant des roches datant de cette \u00e9poque lointaine, les g\u00e9ochimistes canadiens Steven Turgeon et Robert Creaser &#8211; tous deux de l&rsquo;Universit\u00e9 de l&rsquo;Alberta \u00e0 Edmonton &#8211; pensent cependant avoir trouv\u00e9 la solution de cette \u00e9nigme.<\/span><\/p>\n<p align=\"justify\"><span style=\"font-size: small;\">Comparant des \u00e9chantillons de roches provenant d&rsquo;une carri\u00e8re de l&rsquo;Italie et des c\u00f4tes de l&rsquo;Am\u00e9rique du Sud, les scientifiques ont not\u00e9 une forte augmentation de l&rsquo;<\/span><span style=\"font-size: small;\">osmium<\/span><span style=\"font-size: small;\"> &#8211; un \u00e9l\u00e9ment chimique lourd -, dont l&rsquo;analyse a r\u00e9v\u00e9l\u00e9 qu&rsquo;il provenait \u00e0 97% d&rsquo;une source volcanique. Ces \u00e9chantillons \u00e9tant g\u00e9ographiquement tr\u00e8s \u00e9loign\u00e9s, il \u00e9tait probablement qu&rsquo;un \u00e9v\u00e9nement global en \u00e9tait \u00e0 l&rsquo;origine.<\/span><\/p>\n<p align=\"justify\"><span style=\"font-size: small;\">\u00c0 la lumi\u00e8re de leur analyse g\u00e9ochimique, Steven Turgeon et Robert Creaser ont reconstruit la s\u00e9quence des \u00e9v\u00e9nements. Selon ces experts, des volcans sous-marins situ\u00e9s dans la r\u00e9gion des Cara\u00efbes auraient d\u00e9clench\u00e9 une r\u00e9action en cha\u00eene qui a conduit \u00e0 la disparition de l&rsquo;oxyg\u00e8ne des oc\u00e9ans.<\/span><\/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 align=\"justify\"><span style=\"font-size: small;\">Dans un premier temps, le volcanisme sous-marin aurait lib\u00e9r\u00e9 des nutriments et du gaz carbonique, ce qui aurait favoris\u00e9 le d\u00e9veloppement des esp\u00e8ces v\u00e9g\u00e9tales et animales des oc\u00e9ans, notamment le plancton. Ult\u00e9rieurement, la mort de ces organismes aurait consomm\u00e9 une grande quantit\u00e9 d&rsquo;oxyg\u00e8ne, provoquant ce que les sp\u00e9cialistes ont baptis\u00e9 l&rsquo;\u00ab\u00e9v\u00e9nement anoxique oc\u00e9anique 2\u00bb.<\/span><\/p>\n<p align=\"justify\"><span style=\"font-size: small;\">D&rsquo;apr\u00e8s les travaux des g\u00e9ochimistes canadiens, un laps de temps maximum de 23.000 ans se serait \u00e9coul\u00e9 entre les \u00e9ruptions sous-marines des Cara\u00efbes et la disparition de nombreuses esp\u00e8ces dans les oc\u00e9ans.<\/span><\/p>\n<p align=\"justify\"><span style=\"font-size: small;\">Dans le communiqu\u00e9 \u00e9mis par l&rsquo;Universit\u00e9 de l&rsquo;Alberta, Steven Turgeon souligne que cet \u00e9v\u00e9nement serait strictement \u00abterrestre\u00bb, contrairement \u00e0 la plupart des extinctions de masse des esp\u00e8ces dans l&rsquo;histoire de la terre qui sont associ\u00e9es \u00e0 des impacts de m\u00e9t\u00e9ores.<\/span><\/p>\n<p align=\"justify\"><span style=\"font-size: small;\">Fait particuli\u00e8rement int\u00e9ressant en notre \u00e9poque o\u00f9 l&rsquo;on parle constamment de r\u00e9chauffement climatique, Steven Turgeon signale que les \u00e9v\u00e9nements anoxiques se produisent dans des p\u00e9riodes de climat tr\u00e8s chaud o\u00f9 il a augmentation du niveau de gaz carbonique.<\/span><\/p>\n<p align=\"justify\"><span style=\"font-size: small;\">Le g\u00e9ochimiste pr\u00e9cise toutefois que cet \u00e9v\u00e9nement anoxique a eu pour effet de refroidir le climat et de r\u00e9duire le taux de gaz carbonique, car la d\u00e9composition des organismes marins a \u00abemprisonn\u00e9\u00bb le carbone au fond des oc\u00e9ans et form\u00e9 par la m\u00eame occasion une importante source de p\u00e9trole.<\/span><\/p>\n<p align=\"justify\"><span style=\"font-size: small;\">Cette \u00e9tude de Steven Turgeon et Robert Creaser a fait l&rsquo;objet d&rsquo;un article dans la revue <em>Natur<\/em>e.<\/span><\/p>\n<p align=\"justify\"><span style=\"font-size: small;\">source : <\/span><a href=\"http:\/\/science.branchez-vous.com\/\"><span style=\"font-size: small;\">http:\/\/science.branchez-vous.com<\/span><\/a><\/p>\n<p class=\"bawpvc-ajax-counter\" data-id=\"4566\">(573)<\/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>Par une r\u00e9action en cha\u00eene, des \u00e9ruptions volcaniques sous-marines ont provoqu\u00e9 la disparition de l&rsquo;oxyg\u00e8ne dissous dans les oc\u00e9ans, entra\u00eenant&#8230;<\/p>\n","protected":false},"author":1,"featured_media":4567,"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_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":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2},"jetpack_post_was_ever_published":false},"categories":[33],"tags":[3460,3459,1447,3461,528,286,436],"class_list":["post-4566","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-archeologie","tag-93-millions-dannees","tag-cretace","tag-espece","tag-especes-marines","tag-extinction","tag-oxygene","tag-passe","wpcat-33-id"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2015\/04\/Cretaceous-oceanic.jpg?fit=465%2C440&ssl=1","jetpack_shortlink":"https:\/\/wp.me\/p631RN-1bE","jetpack-related-posts":[{"id":19007,"url":"https:\/\/www.laterredufutur.com\/accueil\/retour-vers-le-passe-dans-une-fantastique-simulation\/","url_meta":{"origin":4566,"position":0},"title":"Retour vers le Pass\u00e9 dans une fantastique simulation","author":"Admin","date":"17 avril 2019","format":false,"excerpt":"Retour vers le pass\u00e9 ! o\u00f9 \u00eates vous ? Cr\u00e9tac\u00e9 tardif. Une extinction de masse se produit, entra\u00eenant l'extinction de dinosaures, de nombreux reptiles marins, de tous les reptiles volants et de nombreux invert\u00e9br\u00e9s marins et autres esp\u00e8ces. Les scientifiques pensent que l'extinction a \u00e9t\u00e9 caus\u00e9e par un impact ast\u00e9ro\u00efde\u2026","rel":"","context":"Dans &quot;Arch\u00e9ologie&quot;","block_context":{"text":"Arch\u00e9ologie","link":"https:\/\/www.laterredufutur.com\/accueil\/sujets\/archeologie\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2019\/04\/ancient-earth-globe-paris.jpg?fit=730%2C411&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2019\/04\/ancient-earth-globe-paris.jpg?fit=730%2C411&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2019\/04\/ancient-earth-globe-paris.jpg?fit=730%2C411&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2019\/04\/ancient-earth-globe-paris.jpg?fit=730%2C411&ssl=1&resize=700%2C400 2x"},"classes":[]},{"id":445,"url":"https:\/\/www.laterredufutur.com\/accueil\/une-grande-partie-de-la-vie-marine-pourrait-disparaitre\/","url_meta":{"origin":4566,"position":1},"title":"Une grande partie de la vie marine pourrait dispara\u00eetre","author":"Admin","date":"25 ao\u00fbt 2011","format":false,"excerpt":"Les oc\u00e9ans vont mal. Tr\u00e8s mal. R\u00e9unis mi-mai en congr\u00e8s \u00e0 l'universit\u00e9 d'Oxford, 27 des plus grands sp\u00e9cialistes de la biodiversit\u00e9 marine de six pays ont m\u00eame \u00e9t\u00e9 choqu\u00e9s par l'accumulation de signaux alarmants. En mettant bout \u00e0 bout leurs observations et leurs analyses, une v\u00e9rit\u00e9 effrayante a \u00e9merg\u00e9: la\u2026","rel":"","context":"Dans &quot;Pollution&quot;","block_context":{"text":"Pollution","link":"https:\/\/www.laterredufutur.com\/accueil\/sujets\/pollution\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.laterredufutur.com\/wordpress\/wp-content\/uploads\/2011\/08\/ocean.jpg?resize=350%2C200","width":350,"height":200},"classes":[]},{"id":17298,"url":"https:\/\/www.laterredufutur.com\/accueil\/une-supernova-serait-a-lorigine-dune-vaste-extinction-sur-terre-il-y-a-26-millions-dannees\/","url_meta":{"origin":4566,"position":2},"title":"Une supernova serait \u00e0 l&rsquo;origine d&rsquo;une vaste extinction sur Terre il y a 2,6 millions d&rsquo;ann\u00e9es","author":"Admin","date":"26 d\u00e9cembre 2018","format":false,"excerpt":"Depuis de nombreuses ann\u00e9es, les scientifiques \u00e9tudient comment les supernovas pourraient affecter la vie sur Terre. Les supernovas sont des \u00e9v\u00e9nements extr\u00eamement puissants et, en fonction de leur proximit\u00e9 avec la Terre, ils pourraient avoir des cons\u00e9quences allant du cataclysmique \u00e0 l\u2019inconnu. Mais maintenant, les scientifiques derri\u00e8re un nouveau papier\u2026","rel":"","context":"Dans &quot;Arch\u00e9ologie&quot;","block_context":{"text":"Arch\u00e9ologie","link":"https:\/\/www.laterredufutur.com\/accueil\/sujets\/archeologie\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2018\/12\/Supernova.jpg?fit=1200%2C900&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2018\/12\/Supernova.jpg?fit=1200%2C900&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2018\/12\/Supernova.jpg?fit=1200%2C900&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2018\/12\/Supernova.jpg?fit=1200%2C900&ssl=1&resize=700%2C400 2x, https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2018\/12\/Supernova.jpg?fit=1200%2C900&ssl=1&resize=1050%2C600 3x"},"classes":[]},{"id":24313,"url":"https:\/\/www.laterredufutur.com\/accueil\/les-changements-climatiques-extremes-des-temps-immemoriaux-pourraient-avoir-contribue-a-levolution-des-reptiles\/","url_meta":{"origin":4566,"position":3},"title":"Les changements climatiques extr\u00eames des temps imm\u00e9moriaux pourraient avoir contribu\u00e9 \u00e0 l&rsquo;\u00e9volution des reptiles","author":"Admin","date":"20 ao\u00fbt 2022","format":false,"excerpt":"Une extinction massive il y a 252 millions d'ann\u00e9es n'\u00e9tait qu'une des raisons pour lesquelles les reptiles du Trias sont devenus dominants. Rien de tel qu'une grande extinction de masse pour ouvrir des niches \u00e9cologiques et \u00e9liminer la concurrence, acc\u00e9l\u00e9rant l'\u00e9volution de certains survivants chanceux. Ou est-il? Une nouvelle \u00e9tude\u2026","rel":"","context":"Dans &quot;Arch\u00e9ologie&quot;","block_context":{"text":"Arch\u00e9ologie","link":"https:\/\/www.laterredufutur.com\/accueil\/sujets\/archeologie\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2022\/08\/dinosaure-t-rex.jpg?fit=1024%2C576&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2022\/08\/dinosaure-t-rex.jpg?fit=1024%2C576&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2022\/08\/dinosaure-t-rex.jpg?fit=1024%2C576&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2022\/08\/dinosaure-t-rex.jpg?fit=1024%2C576&ssl=1&resize=700%2C400 2x"},"classes":[]},{"id":16048,"url":"https:\/\/www.laterredufutur.com\/accueil\/une-foret-fossilisee-vieille-de-280-millions-dannees-a-ete-decouverte-en-antarctique\/","url_meta":{"origin":4566,"position":4},"title":"Une for\u00eat fossilis\u00e9e vieille de 280 millions d&rsquo;ann\u00e9es a \u00e9t\u00e9 d\u00e9couverte en Antarctique","author":"Admin","date":"20 novembre 2017","format":false,"excerpt":"Il fut un temps o\u00f9 la glace ne dominait pas l'Antarctique : des chercheurs am\u00e9ricains viennent en effet de trouver les restes d'une for\u00eat vieille de 280 millions d'ann\u00e9es sur le continent austral. L'Antarctique n'a pas toujours \u00e9t\u00e9 une terre de glace. Des scientifiques de l'universit\u00e9 du Wisconsin \u00e0 Milwaukee\u2026","rel":"","context":"Dans &quot;Arch\u00e9ologie&quot;","block_context":{"text":"Arch\u00e9ologie","link":"https:\/\/www.laterredufutur.com\/accueil\/sujets\/archeologie\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2017\/11\/foret-fossile-antarctique.jpg?fit=716%2C415&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2017\/11\/foret-fossile-antarctique.jpg?fit=716%2C415&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2017\/11\/foret-fossile-antarctique.jpg?fit=716%2C415&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2017\/11\/foret-fossile-antarctique.jpg?fit=716%2C415&ssl=1&resize=700%2C400 2x"},"classes":[]},{"id":24831,"url":"https:\/\/www.laterredufutur.com\/accueil\/lepisode-carnien-ou-la-terre-a-connu-2-millions-dannees-de-fortes-pluies-incessantes\/","url_meta":{"origin":4566,"position":5},"title":"L&rsquo;\u00e9pisode Carnien o\u00f9 la Terre a connu 2 millions d&rsquo;ann\u00e9es de fortes pluies incessantes","author":"Admin","date":"2 avril 2023","format":false,"excerpt":"Au cours de son histoire, notre plan\u00e8te aura essuy\u00e9 plusieurs \u00e9pisodes climatiques de longue dur\u00e9e, tels que des \u00e8res glaciaires ou de grandes phases de s\u00e9cheresse. Il y a plus de 230 millions d\u2019ann\u00e9es, peu avant que les dinosaures ne pointent le bout de leur gueule, la Terre fut \u00e9galement\u2026","rel":"","context":"Dans &quot;Arch\u00e9ologie&quot;","block_context":{"text":"Arch\u00e9ologie","link":"https:\/\/www.laterredufutur.com\/accueil\/sujets\/archeologie\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2021\/11\/pluie-tempete.jpg?fit=1101%2C595&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2021\/11\/pluie-tempete.jpg?fit=1101%2C595&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2021\/11\/pluie-tempete.jpg?fit=1101%2C595&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2021\/11\/pluie-tempete.jpg?fit=1101%2C595&ssl=1&resize=700%2C400 2x, https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2021\/11\/pluie-tempete.jpg?fit=1101%2C595&ssl=1&resize=1050%2C600 3x"},"classes":[]}],"jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/posts\/4566","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=4566"}],"version-history":[{"count":1,"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/posts\/4566\/revisions"}],"predecessor-version":[{"id":4568,"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/posts\/4566\/revisions\/4568"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/media\/4567"}],"wp:attachment":[{"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/media?parent=4566"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/categories?post=4566"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/tags?post=4566"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}