{"id":87481,"date":"2026-05-16T10:02:10","date_gmt":"2026-05-16T10:02:10","guid":{"rendered":"https:\/\/www.europesays.com\/cz\/87481\/"},"modified":"2026-05-16T10:02:10","modified_gmt":"2026-05-16T10:02:10","slug":"aljasku-loni-zasahla-druha-nejvetsi-megatsunami-vlna-merila-481-metru","status":"publish","type":"post","link":"https:\/\/www.europesays.com\/cz\/87481\/","title":{"rendered":"Alja\u0161ku loni zas\u00e1hla druh\u00e1 nejv\u011bt\u0161\u00ed megatsunami. Vlna m\u011b\u0159ila 481\u00a0metr\u016f"},"content":{"rendered":"

P\u0159esto\u017ee samotnou vlnu nikdo p\u0159\u00edmo nepozoroval, lid\u00e9 v\u00a0oblasti hl\u00e1sili chaotick\u00e9 podm\u00ednky. Kajak\u00e1\u0159\u016fm kempuj\u00edc\u00edm na ostrov\u011b Harbor Island pobl\u00ed\u017e \u00fast\u00ed fjordu voda odnesla vybaven\u00ed. Cestuj\u00edc\u00ed na mal\u00e9 v\u00fdletn\u00ed lodi v\u00a0sousedn\u00edm fjordu Endicott Arm pak popisovali extr\u00e9mn\u011b siln\u00e9 proudy.<\/p>\n

Kdy\u017e v\u011bdci z\u00a0NASA porovnali sn\u00edmky ze satelitu Landsat<\/a> po\u0159\u00edzen\u00e9 p\u0159ed a\u00a0po ud\u00e1losti, zjistili, \u017ee krajina se v\u00fdrazn\u011b zm\u011bnila. Na fotografi\u00edch byla patrn\u00e1 rozs\u00e1hl\u00e1 oblast sesuvu, ale tak\u00e9 mnoho \u010d\u00e1st\u00ed pob\u0159e\u017e\u00ed a\u00a0ostrov\u016f, kter\u00e9 se ze zelen\u00e9 zbarvily dohn\u011bda pot\u00e9, co p\u0159i\u0161ly o\u00a0ve\u0161kerou vegetaci.<\/p>\n

Mezin\u00e1rodn\u00ed t\u00fdm v\u011bdc\u016f v\u00a0nov\u00e9 studii<\/a> publikovan\u00e9 v\u00a0\u010dasopise Science zkombinoval satelitn\u00ed data, seismick\u00e9 z\u00e1znamy i\u00a0numerick\u00e9 modelov\u00e1n\u00ed, aby p\u0159esn\u011b zjistil, co se ve fjordu odehr\u00e1lo.<\/p>\n

<\/a><\/p>\n

Z dat vypl\u00fdv\u00e1, \u017ee do\u0161lo k\u00a0rozs\u00e1hl\u00e9mu sesuvu p\u016fdy a\u00a0energie n\u00e1sledn\u00e9 tsunami se m\u00edsto rozpt\u00fdlen\u00ed uv\u011bznila uvnit\u0159 fjordu se strm\u00fdmi svahy.<\/p>\n

Foto: NASA Earth Observatory \/ Michala Garrison<\/p>\n

Satelitn\u00ed sn\u00edmek Landsat 9, po\u0159\u00edzen\u00fd 19.\u00a0srpna 2025, ukazuje m\u00edsto sesuvu (Slide area) a\u00a0kde megatsunami dos\u00e1hla nejvy\u0161\u0161\u00edho bodu (Max. Runup).<\/p>\n

Vznikla tak takzvan\u00e1 stojat\u00e1 vlna, ozna\u010dovan\u00e1 jako seiche, kter\u00e1 se po n\u011bkolik hodin p\u0159el\u00e9vala fjordem tam a\u00a0zp\u011bt.<\/p>\n

Megatsunami vy\u0161\u0161\u00ed ne\u017e Eiffelova v\u011b\u017e<\/p>\n

Aby v\u011bdci zjistili, jak vysok\u00e9 vlny byly, vyu\u017eili data z\u00a0nov\u00e9ho satelitu SWOT (Surface Water Ocean Topography). Ten pomoc\u00ed dvojice radarov\u00fdch ant\u00e9n velmi p\u0159esn\u011b m\u011b\u0159\u00ed v\u00fd\u0161ku vodn\u00ed hladiny s\u00a0p\u0159esnost\u00ed p\u0159ibli\u017en\u011b na jeden metr.<\/p>\n

Anal\u00fdza uk\u00e1zala, \u017ee tato megatsunami dos\u00e1hla maxim\u00e1ln\u00ed v\u00fd\u0161ky 481\u00a0metr\u016f, co\u017e z\u00a0n\u00ed \u010din\u00ed druhou nejv\u011bt\u0161\u00ed zaznamenanou megatsunami v\u00a0historii. Pro srovn\u00e1n\u00ed je to o\u00a0v\u00edce ne\u017e 150\u00a0metr\u016f nad vrcholem Eiffelovy v\u011b\u017ee. Vy\u0161\u0161\u00ed vlna byla zaznamen\u00e1na pouze v\u00a0alja\u0161sk\u00e9m z\u00e1livu Lituya Bay v\u00a0roce 1958, kdy dos\u00e1hla v\u00fd\u0161ky 524\u00a0metr\u016f.<\/p>\n

P\u0159ekvapiv\u00e9 bylo, \u017ee m\u011b\u0159en\u00ed ze satelitu SWOT uk\u00e1zala je\u0161t\u011b siln\u011bj\u0161\u00ed a\u00a0vy\u0161\u0161\u00ed vlny, ne\u017e p\u0159edpov\u00eddaly i\u00a0nejpokro\u010dilej\u0161\u00ed po\u010d\u00edta\u010dov\u00e9 simulace.<\/p>\n

Foto: University College London \/ Steve Hicks<\/p>\n

Srovn\u00e1n\u00ed dosud nejvy\u0161\u0161\u00edch zaznamenan\u00fdch megatsunami se sv\u011btozn\u00e1m\u00fdmi v\u011b\u017eemi a\u00a0v\u00fd\u0161kov\u00fdmi budovami<\/p>\n

\u201eSimulace t\u011bchto vln jsou extr\u00e9mn\u011b n\u00e1ro\u010dn\u00e9. I\u00a0modely s\u00a0velmi vysok\u00fdm rozli\u0161en\u00edm maj\u00ed probl\u00e9m zachytit, jak se energie ve slo\u017eit\u00e9 geometrii fjordu odr\u00e1\u017e\u00ed, zachycuje a\u00a0zesiluje,\u201c uvedl jeden z\u00a0autor\u016f studie Thomas Monahan z\u00a0Oxfordsk\u00e9 univerzity<\/a>.<\/p>\n

Jen z\u00e1zrakem bez ob\u011bt\u00ed<\/p>\n

Ot\u00e1zkou z\u016fst\u00e1v\u00e1, co st\u00e1lo za tak masivn\u00edm sesuvem. V\u011bdci vylou\u010dili intenzivn\u00ed sr\u00e1\u017eky, proto\u017ee po\u010das\u00ed bylo v\u00a0p\u0159edchoz\u00edch dnech relativn\u011b klidn\u00e9.<\/p>\n

Podle nich ud\u00e1lost spustil rychl\u00fd \u00fastup ledovce, kter\u00fd destabilizoval svah a\u00a0z\u00e1rove\u0148 vytvo\u0159il nov\u00fd prostor vodn\u00ed hladiny, do n\u011bho\u017e se masa horniny z\u0159\u00edtila.<\/p>\n

V\u011bdci upozor\u0148uj\u00ed, \u017ee s\u00a0pokra\u010duj\u00edc\u00edm \u00fastupem ledovc\u016f m\u016f\u017ee podobn\u00fdch ud\u00e1lost\u00ed p\u0159ib\u00fdvat. Pochopen\u00ed chov\u00e1n\u00ed stojat\u00fdch vln a\u00a0megatsunami tak bude st\u00e1le d\u016fle\u017eit\u011bj\u0161\u00ed pro vyhodnocov\u00e1n\u00ed budouc\u00edch rizik.<\/p>\n

\u201eKlimatick\u00e9 zm\u011bny prob\u00edhaj\u00ed obzvl\u00e1\u0161\u0165 rychle v\u00a0arktick\u00fdch oblastech, co\u017e urychluje procesy vedouc\u00ed k\u00a0podobn\u00fdm ud\u00e1lostem. O\u00a0to d\u016fle\u017eit\u011bj\u0161\u00ed je vyv\u00edjet zp\u016fsoby, jak je monitorovat,\u201c dodal Monahan.<\/p>\n

Jen z\u00e1zrakem si druh\u00e1 nejv\u011bt\u0161\u00ed megatsunami historie nevy\u017e\u00e1dala \u017e\u00e1dn\u00e9 ob\u011bti ani zran\u011bn\u00ed. Oblast toti\u017e pat\u0159\u00ed mezi obl\u00edben\u00e9 destinace v\u00fdletn\u00edch lod\u00ed. Vlna v\u0161ak ude\u0159ila v\u00a0brzk\u00fdch rann\u00edch hodin\u00e1ch, kdy se v\u00a0bezprost\u0159edn\u00edm okol\u00ed nenach\u00e1zelo v\u011bt\u0161\u00ed mno\u017estv\u00ed lid\u00ed.<\/p>\n

Rostouc\u00ed popularita alja\u0161sk\u00fdch plaveb ale podle v\u011bdc\u016f znamen\u00e1, \u017ee riziko podobn\u00fdch katastrof bude v\u00a0budoucnu nar\u016fstat. P\u0159\u00ed\u0161t\u00ed megatsunami u\u017e nemus\u00ed skon\u010dit jen odnesen\u00fdm vybaven\u00edm n\u011bkolika kajak\u00e1\u0159\u016f.<\/p>\n

<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"P\u0159esto\u017ee samotnou vlnu nikdo p\u0159\u00edmo nepozoroval, lid\u00e9 v\u00a0oblasti hl\u00e1sili chaotick\u00e9 podm\u00ednky. Kajak\u00e1\u0159\u016fm kempuj\u00edc\u00edm na ostrov\u011b Harbor Island pobl\u00ed\u017e…\n","protected":false},"author":2,"featured_media":87482,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":"","_share_on_mastodon":"0"},"categories":[11],"tags":[2193,27167,1542,7934,54,16905,113,77,20928,53,52],"class_list":["post-87481","post","type-post","status-publish","format-standard","has-post-thumbnail","category-svet","tag-aljaska","tag-fjord","tag-nasa","tag-sesuvy-pudy","tag-svet","tag-tsunami","tag-usa","tag-veda","tag-vlna","tag-world","tag-world-news"],"share_on_mastodon":{"url":"https:\/\/pubeurope.com\/@cz\/116583684122124638","error":""},"_links":{"self":[{"href":"https:\/\/www.europesays.com\/cz\/wp-json\/wp\/v2\/posts\/87481","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.europesays.com\/cz\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.europesays.com\/cz\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/cz\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/cz\/wp-json\/wp\/v2\/comments?post=87481"}],"version-history":[{"count":0,"href":"https:\/\/www.europesays.com\/cz\/wp-json\/wp\/v2\/posts\/87481\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/cz\/wp-json\/wp\/v2\/media\/87482"}],"wp:attachment":[{"href":"https:\/\/www.europesays.com\/cz\/wp-json\/wp\/v2\/media?parent=87481"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.europesays.com\/cz\/wp-json\/wp\/v2\/categories?post=87481"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.europesays.com\/cz\/wp-json\/wp\/v2\/tags?post=87481"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}