{"id":877,"date":"2005-06-30T09:24:00","date_gmt":"2005-06-30T07:24:00","guid":{"rendered":"https:\/\/kids.esa.int\/esa_s_gravity_explorer\/"},"modified":"2026-10-08T00:33:17","modified_gmt":"2026-10-07T22:33:17","slug":"esa_s_gravity_explorer","status":"publish","type":"post","link":"https:\/\/kids.esa.int\/fr\/esa_s_gravity_explorer\/","title":{"rendered":"L'explorateur de gravit\u00e9 de l'ESA"},"content":{"rendered":"<div class=\"lede\">\n<p>Selon une nouvelle \u00e9tude de l'ESA, le s\u00e9isme de Sumatra du 26 d\u00e9cembre 2004 n'a pas seulement d\u00e9vast\u00e9 une grande partie de la r\u00e9gion, mais il en a aussi l\u00e9g\u00e8rement modifi\u00e9 la gravit\u00e9.<\/p>\n<\/div>\n<p>Lorsque le sol de l'oc\u00e9an Indien s'est d\u00e9plac\u00e9 le long d'une faille de 1000 km pendant le s\u00e9isme, il a cr\u00e9\u00e9 une saillie de 6 m\u00e8tres de haut. Cet \u00e9norme mouvement de roche a instantan\u00e9ment modifi\u00e9 la gravit\u00e9 locale.<\/p>\n<p>Mais ce ph\u00e9nom\u00e8ne n'est pas inhabituel. Les cartes issues des donn\u00e9es satellites montrent que l'attraction gravitationnelle varie d'un endroit \u00e0 l'autre. L'une des raisons \u00e0 cela est la rotation terrestre. Comme elle tourne sur elle-m\u00eame, la Terre forme une bosse au niveau de l'Equateur. Parce qu'elle est plus large de 42 km \u00e0 cet endroit pr\u00e9cis, la force de gravit\u00e9 est plus faible qu'aux autres p\u00f4les.<\/p>\n<p>Les hautes montagnes, les tranch\u00e9es sous-marines et les diff\u00e9rents types de roche \u00e0 l'int\u00e9rieur m\u00eame de la Terre ont \u00e9galement un impact sur la gravit\u00e9. M\u00eame les mar\u00e9es, les courants des oc\u00e9ans et la fonte des calottes glaci\u00e8res influent sur le changement de gravit\u00e9.<\/p>\n<figure class=\"wp-block-image size-large\" data-width=\"1240\" data-credit=\"AOES Medialab\" data-detail-url=\"https:\/\/www.esa.int\/ESA_Multimedia\/Images\/2004\/03\/Artist_s_impression_of_GOCE2\" 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\/2004\/03\/artist_s_impression_of_goce2\/17878219-2-eng-GB\/Artist_s_impression_of_GOCE.jpg\" alt=\"Artist&#x27;s impression of GOCE\"><figcaption>Repr\u00e9sentation artistique du GOCE<\/figcaption><\/figure>\n<p>Actuellement, d'aussi faibles changements de gravit\u00e9 sont difficiles \u00e0 mesurer, mais cela va changer avec le lancement l'ann\u00e9e prochaine du Gravity Field and Ocean Circulation Explorer (GOCE) de l'ESA.<\/p>\n<p>Ce satellite sensible \u00e9tudiera la gravit\u00e9 de mani\u00e8re tr\u00e8s approfondie. Alors qu'il survolera des r\u00e9gions \u00e0 l'attraction gravitationnelle plus ou moins forte, le satellite fera le yo-yo et les instruments enregistreront les variations du champ de gravit\u00e9 rencontr\u00e9es sur sa trajectoire.<\/p>\n<p>Les scientifiques seront ainsi capables de mesurer la quantit\u00e9 de mati\u00e8re en d\u00e9placement soit brusquement, comme lors d'un tremblement de terre, soit progressivement, comme la fonte d'une calotte glaci\u00e8re. Les donn\u00e9es recueillies permettront m\u00eame de rep\u00e9rer les changements de circulation oc\u00e9anique provoqu\u00e9s par le changement climatique.<\/p>","protected":false},"excerpt":{"rendered":"<p>According to a new ESA study, the Sumatran earthquake of 26 December 2004 not only devastated a huge area, but it slightly altered the gravity of that area. When the [&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\/2005\/04\/ers-2_composite_highlighting_tsunami_damage3\/17891576-2-eng-GB\/ERS-2_composite_highlighting_tsunami_damage.jpg","esa_banner_description":"ERS-2 composite highlighting tsunami damage","esa_banner_credit":"ESA","esa_banner_licence":"ESA Standard Licence","esa_banner_detail_url":"https:\/\/www.esa.int\/ESA_Multimedia\/Images\/2005\/04\/ERS-2_composite_highlighting_tsunami_damage3","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-877","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\/877","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=877"}],"version-history":[{"count":4,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/posts\/877\/revisions"}],"predecessor-version":[{"id":4715,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/posts\/877\/revisions\/4715"}],"wp:attachment":[{"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/media?parent=877"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/categories?post=877"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/tags?post=877"},{"taxonomy":"panel","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/panel?post=877"},{"taxonomy":"language","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/language?post=877"},{"taxonomy":"age","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/age?post=877"},{"taxonomy":"duration","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/duration?post=877"},{"taxonomy":"resource_type","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/resource_type?post=877"},{"taxonomy":"audience","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/audience?post=877"},{"taxonomy":"wf_post_folders","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/wf_post_folders?post=877"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}