V\u011bdci objevili d\u016fkazy o obrovsk\u00e9m zem\u011bt\u0159esen\u00ed \u2013 p\u0159\u00edpadn\u011b dvou zem\u011bt\u0159esen\u00edch v rychl\u00e9m sledu \u2013 kter\u00e9 zas\u00e1hlo oblast Puget Sound v severoz\u00e1padn\u00edm Pacifiku p\u0159ibli\u017en\u011b p\u0159ed 1\u202f100 lety. Studie publikovan\u00e1 v \u010dasopise Science Advances<\/em> pou\u017eila datov\u00e1n\u00ed pomoc\u00ed letokruh\u016f strom\u016f a ur\u010dila, \u017ee dva poruchov\u00e9 p\u00e1sma pobl\u00ed\u017e Seattlu praskly b\u011bhem \u0161esti\u2011m\u011bs\u00ed\u010dn\u00edho obdob\u00ed mezi lety 923 a 924 n.\u202fl.<\/p>\n\n Tento objev stav\u00ed do ot\u00e1zky d\u0159\u00edv\u011bj\u0161\u00ed v\u00fdzkumy, je\u017e nazna\u010dovaly, \u017ee oblast je n\u00e1chyln\u00e1 jen k men\u0161\u00edm ot\u0159es\u016fm. Nov\u00e9 z\u00e1v\u011bry nazna\u010duj\u00ed, \u017ee region zahrnuj\u00edc\u00ed Seattle, Tacoma a Olympia ve st\u00e1t\u011b Washington m\u016f\u017ee za\u017e\u00edt extr\u00e9mn\u011bj\u0161\u00ed zem\u011bt\u0159esen\u00ed, ne\u017e se dosud p\u0159edpokl\u00e1dalo.<\/p>\n\n Zem\u011bt\u0159esen\u00ed, p\u0159i nich\u017e dojde k sou\u010dasn\u00e9mu poru\u0161en\u00ed n\u011bkolika zlomov\u00fdch p\u00e1s\u016f, jsou \u010dasto nejni\u010div\u011bj\u0161\u00edmi ot\u0159esy, kter\u00e9 oblast m\u016f\u017ee za\u017e\u00edt. P\u0159esto jsou vz\u00e1cn\u00e1 a obt\u00ed\u017en\u011b zaznamenateln\u00e1 v historick\u00fdch z\u00e1znamech. Zem\u011bt\u0159esen\u00ed popsan\u00e9 v nov\u00e9 studii pravd\u011bpodobn\u011b vzniklo jako v\u00fdsledek v\u00edcen\u00e1sobn\u00e9ho poru\u0161en\u00ed zlom\u016f, co\u017e jej \u010din\u00ed zvl\u00e1\u0161t\u011b nebezpe\u010dn\u00fdm.<\/p>\n\n Aby ur\u010dili na\u010dasov\u00e1n\u00ed starov\u011bk\u00e9ho ot\u0159esu, v\u00fdzkumn\u00edci analyzovali letokruhy jedl\u00edka douglase z \u0161esti m\u00edst v okol\u00ed Puget Sound. Porovn\u00e1n\u00edm letokruh\u016f mezi sebou a s referen\u010dn\u00ed chronologi\u00ed zjistili, \u017ee stromy zem\u0159ely mezi \u0159\u00edjnem 923 a b\u0159eznem 924. To jim umo\u017enilo vymezit ot\u0159esy do tohoto \u0161esti\u2011m\u011bs\u00ed\u010dn\u00edho okna.<\/p>\n\n Pro zv\u00fd\u0161en\u00ed jistoty v\u00fdsledku t\u00fdm ve vzorc\u00edch letokruh\u016f hledal charakteristick\u00fd znak usnad\u0148uj\u00edc\u00ed dataci: \u0161pi\u010dku ve vesm\u00edrn\u00e9m z\u00e1\u0159en\u00ed zn\u00e1mou jako ud\u00e1lost Miyake. Tato ud\u00e1lost, pravd\u011bpodobn\u011b sol\u00e1rn\u00ed erupce nebo v\u00fdbuch hv\u011bzdy, zanechala v\u00fdrazn\u00fd n\u00e1r\u016fst koncentrace uhl\u00edku\u201114 ve stromech. Identifikovali takovou ud\u00e1lost mezi lety 774 a 775 n.\u202fl. a pou\u017eili ji jako referen\u010dn\u00ed bod, \u010d\u00edm\u017e potvrdili, \u017ee posledn\u00ed letokruh ve vzorc\u00edch poch\u00e1z\u00ed z roku 923.<\/p>\n\n Na z\u00e1klad\u011b v\u00fdsledk\u016f odhaduj\u00ed v\u00fdzkumn\u00edci, \u017ee b\u011bhem \u0161esti\u2011m\u011bs\u00ed\u010dn\u00edho obdob\u00ed do\u0161lo bu\u010f k dv\u011bma \u00fazce \u010dasovan\u00fdm ot\u0159es\u016fm o magnitud\u011b 7,5 a 7,3, nebo k jedin\u00e9mu v\u00edcen\u00e1sobn\u00e9mu ot\u0159esu p\u0159ibli\u017en\u011b o magnitud\u011b 7,8. Sc\u00e9n\u00e1\u0159 jednoho ot\u0159esu je asi t\u0159ikr\u00e1t pravd\u011bpodobn\u011bj\u0161\u00ed ne\u017e dva odd\u011blen\u00e9 ot\u0159esy.<\/p>\n\n Zem\u011bt\u0159esen\u00ed o magnitud\u011b 7,8, jak\u00e9 je pops\u00e1no v nov\u00e9 publikaci, by uvolnilo 38\u2011kr\u00e1t v\u00edce energie ne\u017e ot\u0159es o magnitud\u011b 6,7, kter\u00fd byl z\u00e1kladem p\u0159edchoz\u00edch model\u016f nebezpe\u010d\u00ed. To by pravd\u011bpodobn\u011b vyvolalo m\u00edstn\u00ed tsunami a zp\u016fsobilo rozs\u00e1hl\u00e9 \u0161kody i ob\u011bti.<\/p>\n\n Zji\u0161t\u011bn\u00ed studie zd\u016fraz\u0148uj\u00ed pot\u0159ebu aktualizovat modely nebezpe\u010d\u00ed tak, aby zohled\u0148ovaly mo\u017enost ot\u0159es\u016f t\u00e9to velikosti. Sou\u010dasn\u00e9 modely nepo\u010d\u00edtaj\u00ed s tak siln\u00fdmi ot\u0159esy, co\u017e m\u016f\u017ee v\u00e9st k podcen\u011bn\u00ed potenci\u00e1ln\u00edch rizik a nedostate\u010dn\u00e9 p\u0159ipravenosti na katastrofy.<\/p>\n\n I kdy\u017e je pravd\u011bpodobnost tak extr\u00e9mn\u00edho jevu v konkr\u00e9tn\u00edm roce n\u00edzk\u00e1, studie podtrhuje d\u016fle\u017eitost p\u0159ipravenosti na katastrof\u00e1ln\u00ed zem\u011bt\u0159esen\u00ed. Stavebn\u00ed p\u0159edpisy a pl\u00e1ny nouzov\u00e9 reakce by m\u011bly b\u00fdt p\u0159ezkoum\u00e1ny a aktualizov\u00e1ny tak, aby odr\u00e1\u017eely mo\u017enost v\u011bt\u0161\u00edch ot\u0159es\u016f, ne\u017e se d\u0159\u00edve p\u0159edpokl\u00e1dalo.<\/p>\n\n Zem\u011bt\u0159esen\u00ed popsan\u00e9 v nov\u00e9 studii bylo pravd\u011bpodobn\u011b nejintenzivn\u011bj\u0161\u00ed v posledn\u00edch 16\u202f000 letech. To podtrhuje v\u00fdznam pokra\u010duj\u00edc\u00edho v\u00fdzkumu a monitoringu pro lep\u0161\u00ed pochopen\u00ed rizik zem\u011bt\u0159esen\u00ed v severoz\u00e1padn\u00edm Pacifiku a pro v\u00fdvoj efektivn\u00edch strategi\u00ed zm\u00edr\u0148ov\u00e1n\u00ed n\u00e1sledk\u016f.<\/p>","protected":false},"excerpt":{"rendered":" Masivn\u00ed dvou\u2011poruchov\u00e9 zem\u011bt\u0159esen\u00ed mohlo zas\u00e1hnout severoz\u00e1padn\u00ed Pacifik p\u0159ed 1\u202f100 lety Nov\u00e1 studie odhaluje intenzitu starov\u011bk\u00e9ho zem\u011bt\u0159esen\u00ed V\u011bdci objevili d\u016fkazy o obrovsk\u00e9m zem\u011bt\u0159esen\u00ed \u2013 p\u0159\u00edpadn\u011b dvou zem\u011bt\u0159esen\u00edch v rychl\u00e9m sledu \u2013…<\/p>\n","protected":false},"author":2,"featured_media":25411,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[728],"tags":[19690,19691,6748,8053,1643,613,4866],"class_list":["post-14684","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-earth-sciences","tag-fault-zones","tag-hazard-mitigation","tag-tree-rings","tag-pacific-northwest","tag-ancient-history","tag-scientific-discovery","tag-earthquakes"],"_links":{"self":[{"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/posts\/14684","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/comments?post=14684"}],"version-history":[{"count":2,"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/posts\/14684\/revisions"}],"predecessor-version":[{"id":25412,"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/posts\/14684\/revisions\/25412"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/media\/25411"}],"wp:attachment":[{"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/media?parent=14684"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/categories?post=14684"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/tags?post=14684"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}Riziko zem\u011bt\u0159esen\u00ed bylo podcen\u011bno<\/h2>\n\n
Zem\u011bt\u0159esen\u00ed s poruchou v\u00edce zlom\u016f<\/h2>\n\n
Letokruhy odhalily \u010dasov\u00e1n\u00ed ot\u0159esu<\/h2>\n\n
Ud\u00e1lost Miyake potvrzuje datov\u00e1n\u00ed<\/h2>\n\n
Magnituda a uvoln\u011bn\u00e1 energie<\/h2>\n\n
Modely nebezpe\u010d\u00ed vy\u017eaduj\u00ed aktualizaci<\/h2>\n\n
P\u0159\u00edprava na nejhor\u0161\u00ed sc\u00e9n\u00e1\u0159<\/h2>\n\n
D\u016fsledky pro severoz\u00e1padn\u00ed Pacifik<\/h2>\n\n