{"id":554,"date":"2013-12-06T10:12:00","date_gmt":"2013-12-06T09:12:00","guid":{"rendered":"https:\/\/kids.esa.int\/huge_earthquake_changed_earth_s_gravity\/"},"modified":"2026-10-08T00:29:34","modified_gmt":"2026-10-07T22:29:34","slug":"huge_earthquake_changed_earth_s_gravity","status":"publish","type":"post","link":"https:\/\/kids.esa.int\/fr\/huge_earthquake_changed_earth_s_gravity\/","title":{"rendered":"Un important s\u00e9isme modifie la gravit\u00e9 terrestre"},"content":{"rendered":"<div class=\"lede\">\n<p>Bien que le satellite GOCE de l\u2019ESA se soit enti\u00e8rement consum\u00e9 durant sa rentr\u00e9e atmosph\u00e9rique il y a quelques semaines, l'unique mission qu'il a men\u00e9e continue de nous r\u00e9v\u00e9ler des surprises. La derni\u00e8re d\u00e9couverte de GOCE, tout \u00e0 fait inattendue, a mis en \u00e9vidence un changement de la force de gravit\u00e9 terrestre suite \u00e0 l\u2019important s\u00e9isme qui a frapp\u00e9 le Japon en 2011.<\/p>\n<\/div>\n<p>Le satellite GOCE, structur\u00e9 en forme de fl\u00e8che, avait \u00e9t\u00e9 sp\u00e9cialement con\u00e7u pour \u00e9laborer la cartographie la plus pr\u00e9cise et la plus d\u00e9taill\u00e9e jamais r\u00e9alis\u00e9e des variations du champ de gravit\u00e9 terrestre. GOCE, qui avait \u00e9t\u00e9 plac\u00e9 sur une orbite quasi polaire, a vu sa trajectoire l\u00e9g\u00e8rement \u00e9voluer en raison de la force gravitationnelle de notre Terre.<\/p>\n<p>Des analyses minutieuses des donn\u00e9es renvoy\u00e9es par GOCE pendant sa mission de quatre ans ont permis d\u2019\u00e9laborer un mod\u00e8le encore plus pr\u00e9cis du g\u00e9o\u00efde (la repr\u00e9sentation de r\u00e9f\u00e9rence de la gravit\u00e9 terrestre). En outre, la sensibilit\u00e9 remarquable de son gradiom\u00e8tre a facilit\u00e9 l\u2019\u00e9tude d\u2019autres caract\u00e9ristiques de notre plan\u00e8te, comme les courants oc\u00e9aniques, la variation du niveau des oc\u00e9ans, l\u2019altitude de la surface terrestre et la structure stratifi\u00e9e de la cro\u00fbte rocheuse de la Terre. GOCE a \u00e9galement d\u00e9tect\u00e9 des traces de vent solaire ainsi que les ondes acoustiques \u00e9mises dans l'atmosph\u00e8re apr\u00e8s le violent s\u00e9isme qui a frapp\u00e9 le Japon le 11 mars 2011.<\/p>\n<figure class=\"wp-block-image size-large\" data-width=\"4446\" data-credit=\"DGFI\/TU Delft\" data-detail-url=\"https:\/\/www.esa.int\/ESA_Multimedia\/Images\/2013\/12\/Gravity_scar_over_Japan2\" data-licence=\"ESA Standard Licence\" data-licence-url=\"https:\/\/www.esa.int\/ESA_Multimedia\/Terms_and_conditions_of_use_of_images_and_videos_available_on_the_esa_website\"><img decoding=\"async\" loading=\"lazy\" style=\"max-width:100%;height:auto\" src=\"https:\/\/www.esa.int\/var\/esa\/storage\/images\/esa_multimedia\/images\/2013\/12\/gravity_scar_over_japan2\/17911676-2-eng-GB\/Gravity_scar_over_Japan.jpg\" alt=\"Gravity scar over Japan\"><figcaption>Une cicatrice gravitationnelle au-dessus du Japon<\/figcaption><\/figure>\n<p>Aujourd\u2019hui, GOCE surprend une fois encore la communaut\u00e9 scientifique en d\u00e9tectant des changements dans la force de gravit\u00e9 terrestre apr\u00e8s le terrible s\u00e9isme, d\u2019une magnitude de 9,0, qui a d\u00e9vast\u00e9 le Japon il y a deux ans. Des chercheurs allemands et n\u00e9erlandais ont en effet analys\u00e9 les r\u00e9sultats fournis par GOCE, et ont d\u00e9couvert que le tremblement de terre a clairement modifi\u00e9 la force de gravit\u00e9 exerc\u00e9e sur l\u2019\u00eele d\u2019Honshu et sur les fonds marins \u00e0 proximit\u00e9. C\u2019est la premi\u00e8re fois que les donn\u00e9es de GOCE nous r\u00e9v\u00e8lent des changements environnementaux progressifs.<\/p>\n<p>Par ailleurs, l\u2019amplitude et la localisation des changements gravitationnels mesur\u00e9s par GOCE diff\u00e8rent des pr\u00e9visions initiales. En combinant les donn\u00e9es de GOCE aux informations de la mission am\u00e9ricano-allemande GRACE et \u00e0 des sources compl\u00e9mentaires, les chercheurs parviendront \u00e0 obtenir une repr\u00e9sentation plus pr\u00e9cise des \u00e9v\u00e9nements ayant eu lieu lors du s\u00e9isme sous-marin.<\/p>","protected":false},"excerpt":{"rendered":"<p>Although ESA\u2019s GOCE satellite burned up during re-entry into Earth\u2019s atmosphere a few weeks ago, this unique mission keeps on springing surprises. The latest unexpected discovery is that GOCE detected [&hellip;]<\/p>\n","protected":false},"author":5,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"esa_banner_image":"https:\/\/www.esa.int\/var\/esa\/storage\/images\/esa_multimedia\/images\/2013\/12\/goce\/17888098-2-eng-GB\/GOCE.jpg","esa_banner_description":"GOCE","esa_banner_credit":"ESA \/AOES Medialab","esa_banner_licence":"ESA Standard Licence","esa_banner_detail_url":"https:\/\/www.esa.int\/ESA_Multimedia\/Images\/2013\/12\/GOCE","esa_external_url":"","esa_external_new_window":false,"_jetpack_feature_clip_id":0,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_post_was_ever_published":true},"categories":[42,10,59],"tags":[],"panel":[],"language":[],"age":[],"duration":[],"resource_type":[],"audience":[],"wf_post_folders":[],"class_list":["post-554","post","type-post","status-publish","format-standard","hentry","category-earth","category-learn","category-natural-disasters"],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/posts\/554","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/users\/5"}],"replies":[{"embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/comments?post=554"}],"version-history":[{"count":4,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/posts\/554\/revisions"}],"predecessor-version":[{"id":4546,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/posts\/554\/revisions\/4546"}],"wp:attachment":[{"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/media?parent=554"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/categories?post=554"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/tags?post=554"},{"taxonomy":"panel","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/panel?post=554"},{"taxonomy":"language","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/language?post=554"},{"taxonomy":"age","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/age?post=554"},{"taxonomy":"duration","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/duration?post=554"},{"taxonomy":"resource_type","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/resource_type?post=554"},{"taxonomy":"audience","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/audience?post=554"},{"taxonomy":"wf_post_folders","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/wf_post_folders?post=554"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}