{"id":12637,"date":"2026-09-13T16:55:19","date_gmt":"2026-09-13T14:55:19","guid":{"rendered":"https:\/\/www.imbe.fr\/?p=12637"},"modified":"2026-09-14T08:48:35","modified_gmt":"2026-09-14T06:48:35","slug":"il-y-a-14-300-ans-une-tempete-solaire-exceptionnelle-enregistree-dans-les-alpes","status":"publish","type":"post","link":"https:\/\/www.imbe.fr\/fr\/il-y-a-14-300-ans-une-tempete-solaire-exceptionnelle-enregistree-dans-les-alpes\/","title":{"rendered":"Il y a 14 300 ans, une temp\u00eate solaire exceptionnelle enregistr\u00e9e dans les Alpes"},"content":{"rendered":"\t\t<div data-elementor-type=\"wp-post\" data-elementor-id=\"12637\" class=\"elementor elementor-12637\" data-elementor-post-type=\"post\">\n\t\t\t\t<div class=\"elementor-element elementor-element-bea4e05 e-flex e-con-boxed e-con e-parent\" data-id=\"bea4e05\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t\t<div class=\"e-con-inner\">\n\t\t\t\t<div class=\"elementor-element elementor-element-cf11ce3 elementor-widget elementor-widget-image\" data-id=\"cf11ce3\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"image.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<img fetchpriority=\"high\" decoding=\"async\" width=\"722\" height=\"486\" src=\"https:\/\/www.imbe.fr\/wp-content\/uploads\/2026\/09\/Miramont-publi.jpg\" class=\"attachment-2048x2048 size-2048x2048 wp-image-12658\" alt=\"\" srcset=\"https:\/\/www.imbe.fr\/wp-content\/uploads\/2026\/09\/Miramont-publi.jpg 722w, https:\/\/www.imbe.fr\/wp-content\/uploads\/2026\/09\/Miramont-publi-300x202.jpg 300w, https:\/\/www.imbe.fr\/wp-content\/uploads\/2026\/09\/Miramont-publi-18x12.jpg 18w\" sizes=\"(max-width: 722px) 100vw, 722px\" \/>\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-dd7f15e elementor-widget elementor-widget-text-editor\" data-id=\"dd7f15e\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p class=\"PDq2pG_selectionAnchorContainer\" data-start=\"206\" data-end=\"328\"><strong data-start=\"206\" data-end=\"328\">Des pins subfossiles des Alpes du Sud r\u00e9v\u00e8lent la trace d\u2019un \u00e9v\u00e9nement solaire exceptionnel survenu il y a 14 300 ans.<\/strong><\/p><p data-start=\"330\" data-end=\"744\">Une \u00e9tude men\u00e9e par <strong data-start=\"350\" data-end=\"449\">Edouard Bard, <a href=\"https:\/\/www.imbe.fr\/fr\/annuaire\/cecile-miramont\/\">C\u00e9cile Miramont<\/a>, Frauke Rostek, Thibaut Tuna, Fr\u00e9d\u00e9ric Guibal,<a href=\"https:\/\/www.imbe.fr\/fr\/annuaire\/christian-marschal\/\"> Christian Marschal<\/a><\/strong> et <strong>Timothy Heaton<\/strong>, met en \u00e9vidence un <strong>\u00e9v\u00e9nement solaire de particules extr\u00eame<\/strong> survenu vers 14 300 ans avant le pr\u00e9sent, gr\u00e2ce \u00e0 l\u2019analyse de pins subfossiles conserv\u00e9s sur les berges du Drouzet, dans les Alpes fran\u00e7aises.<\/p><p class=\"isSelectedEnd\"><strong>Les analyses dendrochronologiques, combin\u00e9es \u00e0 des mesures de radiocarbone de haute pr\u00e9cision r\u00e9alis\u00e9es au CEREGE, ont permis de reconstituer pr\u00e8s de 700 ans d\u2019archives et de d\u00e9tecter une augmentation brutale d\u2019environ 30 \u2030 du \u0394\u00b9\u2074C.<\/strong><\/p><p class=\"isSelectedEnd\">Cette signature t\u00e9moigne d\u2019une production exceptionnelle d\u2019isotopes cosmog\u00e9niques, compatible avec un \u00e9pisode extr\u00eamement intense de particules solaires. Les simulations du cycle du carbone, contraintes notamment par les donn\u00e9es de ^10Be de la carotte glaciaire GRIP, confortent cette interpr\u00e9tation.<\/p><p class=\"isSelectedEnd\"><strong>Les mod\u00e8les atmosph\u00e9riques indiquent que cet \u00e9v\u00e9nement pourrait \u00eatre le plus puissant \u00e9v\u00e9nement solaire de particules extr\u00eame identifi\u00e9 \u00e0 ce jour<\/strong>, largement sup\u00e9rieur aux plus importants \u00e9v\u00e9nements de rayonnement cosmique enregistr\u00e9s au cours des derni\u00e8res d\u00e9cennies.<\/p><p class=\"isSelectedEnd\"><strong>Ces r\u00e9sultats montrent ainsi que les arbres subfossiles peuvent constituer de v\u00e9ritables archives naturelles de l\u2019activit\u00e9 solaire pass\u00e9e et permettent de documenter des \u00e9v\u00e9nements solaires extr\u00eames bien ant\u00e9rieurs aux observations instrumentales.<\/strong><\/p><p><strong>Une \u00e9tude \u00e0 retrouver dans<\/strong> <strong><em>Philosophical Transactions of the Royal Society A<\/em><\/strong> <strong>:<\/strong> <em><a href=\"https:\/\/royalsocietypublishing.org\/rsta\/article\/384\/2329\/20250289\/483259\/Radiocarbon-dating-of-subfossil-trees-from-the\" target=\"_blank\" rel=\"noopener\">Radiocarbon dating of subfossil trees from the southern French Alps and the extreme solar particle event at ca 14 300 cal yr BP<\/a><\/em><\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t","protected":false},"excerpt":{"rendered":"<p>Des pins subfossiles des Alpes du Sud r\u00e9v\u00e8lent la trace d\u2019un \u00e9v\u00e9nement solaire exceptionnel survenu il y a 14 300 ans. Une \u00e9tude men\u00e9e par Edouard Bard, C\u00e9cile Miramont, Frauke [&hellip;]<\/p>\n","protected":false},"author":300,"featured_media":12658,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[23],"tags":[],"class_list":["post-12637","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-publication"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.imbe.fr\/fr\/wp-json\/wp\/v2\/posts\/12637","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.imbe.fr\/fr\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.imbe.fr\/fr\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.imbe.fr\/fr\/wp-json\/wp\/v2\/users\/300"}],"replies":[{"embeddable":true,"href":"https:\/\/www.imbe.fr\/fr\/wp-json\/wp\/v2\/comments?post=12637"}],"version-history":[{"count":17,"href":"https:\/\/www.imbe.fr\/fr\/wp-json\/wp\/v2\/posts\/12637\/revisions"}],"predecessor-version":[{"id":12673,"href":"https:\/\/www.imbe.fr\/fr\/wp-json\/wp\/v2\/posts\/12637\/revisions\/12673"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.imbe.fr\/fr\/wp-json\/wp\/v2\/media\/12658"}],"wp:attachment":[{"href":"https:\/\/www.imbe.fr\/fr\/wp-json\/wp\/v2\/media?parent=12637"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.imbe.fr\/fr\/wp-json\/wp\/v2\/categories?post=12637"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.imbe.fr\/fr\/wp-json\/wp\/v2\/tags?post=12637"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}