Pausiku hwaChikunguru 9, 1958, Lituya Bay yeAlaska yakatambura chimwe chezviitiko zvinoshamisa mundangariro mhenyu. Kudengenyeka kwenyika kwakasvika 7,9 pachikero cheRichter kwakazunguza bay rose. Dambudziko rakanga risiri kudengenyeka kwenyika chete, asi masaisai aakagadzira, akareba kupfuura hafu yekiromita. Mafungu makuru munhoroondo yakanyorwa. Ndakaumbwa na tsunami yakakura kwazvo pasi rose inozivikanwa kusvikira nhasi.
Muchinyorwa chino tichakuudza zvese zvaunoda kuziva nezve tsunami yakakura kwazvo pasi rose, maitiro ayo uye kukuvadza kwayakaita.
Tsunami yakakura kwazvo pasi rose
Iyo Fairweather Fault iri padyo neLituya Bay muAlaska. Saka nekudaro, inzvimbo yechiitiko chekudengenyeka kwenyika, uko kumwe kana kumwe kudengenyeka kukuru kunoitika mumakumi mashoma emakore. Nekudaro, iyo kubva 1958 yakanyanya kukwirira. Mukuwedzera kune izvozvo, chimwe chinhu chakakosha chakawedzerwa: dombo rakaguma mumvura uye rakagadzira mafungu asina kumboitika.
Inofungidzirwa kuti 30 mamiriyoni cubic metres edombo akadonha kubva pakakwirira anenge 900 metres. Dombo rinopenga iri hariite chimwe chinhu kunze kwekukonzera masaisai makuru. Kunyangwe pasina graphic mafaira enguva ino kana maturusi anogona kurekodha, kune humbowo hunotevera. Makumi emakore gare gare, kana zvisaririra zvekukuvadzwa kwemafungu zvichiri kuoneka, tinowana humbowo. Ongororo yakaitwa muna 2010 yechikomo chiri pedyo yakaratidza kuchinja kwezvinomera kwayakanga yaita. Pakureba kwemamita 500, pane shanduko yakakosha yezvinomera zvidiki pane kumusoro. Nyanzvi dzepasi uye vaongorori vanofungidzira kuti masaisai anogona kusvika mamita 524 muurefu.
Kuedza kuderedza kukuvadza
Kuvharwa kwehukama kweLituya Bay hakuna kubatsira kuderedza njodzi. Kufanana nenzvimbo yemvura yakakomberedzwa nenyika, masaisai acho anotsvaira chinhu chiri chose chiri pedyo uye, nenzira yakafanana, anoita kuti chirebe nokuderedza nzvimbo yacho pamativi. Yakanga yakakura kudaro yakatsvaira nyika yakapoteredza uye pakupedzisira yakadirana muGulf of Alaska.
Kugara kukuru panguva iyoyo kwaiva Yakutat, iyo yakakuvadzwa zvishoma tichifunga nezvehukuru hwekudengenyeka kwenyika uye ukuru hwemafungu. Zvinozivikanwa kuti vanhu vatatu vakafa pachitsuwa cheYakutat, makiromita 200 kubva pagungwa, nekuti vamwe vavo vakavigwa mugungwa. Kuseri mubay, vanhu vaviri vaiva muchikepe chehove vakakukurwawo.
Nzvimbo iyi chikamu cheGlacier Bay National Park uye Preserve, saka nzvimbo yakapoteredza haigari vanhu, asi zvikepe zvitatu zvekuredza zvaiva mukati mebay pakaitika kudengenyeka kwenyika. Ngarava yaVivian naBill Swanson yeBadger yakatakurwa ichipinda mumuromo meiyo bay nemafungu "achitsvedza nekumaodzanyemba kweAlaska" ndokuzonyura. Sezvineiwo, muchato wacho wakanunurwa nerimwe igwa. Howard Uhlrich nemwanakomana wake ane makore manomwe vakakwanisa kunzvenga masaisai nechikepe chavo Edrie, vakananga kwavari. Asi Orville Wagner nemudzimai wake vakapwanyiwa kusvika vafa nemudhuri wemvura waiva muchikepe cheSomermore.
MuYakutat, iyo chete yekugara zvachose padyo neiyo epicenter panguva iyoyo, zvivakwa zvakaita semabhiriji, docks uye mapaipi zvakakuvadzwa. Imwe shongwe yakadhirika uye imba yakakuvadzwa zvokusagadzirisika. Mamota ejecha nekuparuka zvakaoneka kubva kumhenderekedzo yekumaodzanyemba kwakadziva kumabvazuva, uye tambo dzepasi pegungwa dzaitsigira hurongwa hwekufambiswa kwemashoko hweAlaska dzakadimburwa.
Mafungu etsunami yakakura kwazvo pasi rose akakonzera kukanganisa kwezvinomera zvepromontory zvakatenderedza nzvimbo iyo dombo rakawira, kusvika ku520 metres kureba, pamwe nekumahombekombe egungwa.
seismic geology
Zvakaitika muLituya ndezvekuzivikanwa kweiyo inonzi hofori tsunami. Mafungu chete anopfuura 100 metres anowira muchikamu ichi. Nzvimbo yeAlaska kwakaitika kudengenyeka kwenyika iri pane fault line iyo kufamba kwayo kwakakonzera kudengenyeka kwenyika kukuru. Nzvimbo yeLituya Bay ine nhoroondo yezviitiko zvetsunami, asi iyo eChiitiko cha1958 chaive chekutanga kunyorwa nedata rakakwana.
Kunyange zvichiri kupokana kuti ndezvipi musanganiswa wezvinhu zvakaburitsa danho rakadaro, zviri pachena kuti kwaiva kudengenyeka kwenyika kwakakonzera 30 million cubic metres yezvinhu kuti aparadze chando. Zvakare, musuwo webay idiki kwazvo, izvo zvinoreva kuti mvura yakawanda yakavharirwa pakati pemakomo. Iyi nharaunda ine maitiro ekuzvarwa ekukonzeresa masaisai makuru, kungave kuburikidza nekudonha kwevhu kana kudengenyeka.
Ongororo yakaitwa muna 2010 yakagumisa kuti chiitiko che "double slide" chainyanya kuitika: rockslide yakarova padyo nepamusoro weLituya Glacier, zvichiita kuti 400 cubic metres echando iparadze munwe wepamberi wechando, uye pamwe jekiseni rakakura. yemvura pasi pe glacier. Iyo yakareruka glacier inosimuka isati yanyura, uye huwandu hukuru hwekuvharirwa kuzadza (subglacial uye preglacial sediments) iyo yakavharirwa pasi pemvura yechando uye yakasunungurwa nekudengenyeka kwenyika inopotsa yaburitswa sechipiri, shanduko huru.
Tsunami yakakura kwazvo pasi rose uye mazaya echando ari kunyunguduka
Masayendisiti anotsanangura mhedzisiro yekunyungudika. Alaska ine mamwe mahombe echando epasirese, ayo anogona kudarika kiromita mukobvu uye anofukidza mazana emakiromita mativi. Huremu hweaizi hunoita kuti nyika inyure, uye kana mazaya echando anyunguduka, pasi rinosimuka zvakare, sepasisina chipanji chinosvinwa. Zvinongoitika kuti kudziya kwepasi kuri kukonzera kurasikirwa kweaizi, saka kusimuka kwepasi chinhu chakajairika kupfuura mumazana emakore Kuchinja Kweindasitiri kusati kwaitika.
Kukwirira kwenzvimbo kune zvikamu zviviri. Kune rimwe divi, pane inonzi nenyanzvi "elastic effect", iyo inoitika kana pasi pakasimuka zvakare pakarepo mushure mekunge chivharo chechando chinotsikirira nehuremu hwayo chanyangarika. Kune rimwe divi, kune inonzi terrestrial "mantle effect", iyo inobva yayerera ichidzokera mudunhu kuti iwane nzvimbo.
Vatsvagiri vakawana chinongedzo pakati pekufamba kwejasi kuparadzira uye kudengenyeka kwenyika kukuru kumaodzanyemba kwakadziva kumabvazuva kweAlaska, uko mazaya echando ave kunyungudika kwemakore anopfuura 200. Southern Alaska iri panosangana kuchamhembe kweAmerican continental plate uye Pacific plate. Mahwendefa aya anofamba achirwisana pamwero weanenge masendimita mashanu pagore, zvichikonzera kudengenyeka kwenyika nguva dzose.
Ndinovimba kuti neruzivo urwu unogona kudzidza zvakawanda nezve tsunami yakakura kwazvo pasi rose uye maitiro ayo.