Yintoni i-megatsunami

Un megatsunami liza elikhulu kakhulu elenziwe yintshukumo enkulu kunye nekhawulezileyo yemathiriyeli kumzimba wamanzi. Izazinzulu zoyika ukwenzeka kolu hlobo lweziganeko ngenxa yomthamo omkhulu wokutshatyalaliswa kweendawo eziselunxwemeni.

Ngesi sizathu, siza kunikezela eli nqaku ukuze sikuxelele ukuba yintoni na i-megatsunami, zithini iimpawu zayo, iziphumo kunye nokwenzeka kokwenzeka kwayo.

Yintoni i-megatsunami

I-Megatsunami ineempawu ezihluke ngokupheleleyo kunezinye iindidi eziqhelekileyo zeetsunami. Uninzi lweetsunami zemveli zibangelwa yintshukumo yetectonic ephantsi kolwandle (ukushukuma kwamacwecwe omhlaba) kwaye oko kwenzeka ecaleni kwemida yeepleyiti kwaye ziziphumo zeenyikima kunye nokunyuka okanye ukuhla kolwandle, okubangela ukususwa kwamanzi.

Iitsunami eziqhelekileyo zibonisa amaza angekho nzulu elwandle, kwaye njengoko ulwandle lusiba nzulu kwaye lusondela emhlabeni, amanzi aqala "ukudiba" ukuya kumaza obude ukuya kuthi ga kwi-10 yeemitha. Endaweni yoko, iitsunami ezinkulu zenzeka xa isixa esikhulu semathiriyeli siwela ngokukhawuleza okanye kufuphi namanzi (umzekelo, ukusuka kwimpembelelo yemeteorite okanye intaba-mlilo).

Banokuba nokuphakama kwamaza amakhulu kakhulu, ukusuka kumakhulu eemitha kwaye mhlawumbi namawaka eemitha, ukodlula kakhulu nayiphi na itsunami eqhelekileyo. Ezi ndawo ziphakamileyo zamaza zenzeka xa amanzi "efafazwa" kwaye esasazwa yimpembelelo okanye ukufuduswa.

Imizekelo yee-mega tsunami zale mihla iquka ezo zinxulunyaniswa nogqabhuko-dubulo lwe-Krakatoa ngo-1883 (ugqabhuko-mlilo), iLituya Bay mega tsunami ngo-1958 (ubutyobo bungena echwebeni), kunye namaza abangelwa kukudilika komhlaba kwedama. umgangatho wolwandle (intlambo) Imizekelo yamandulo ibandakanya ukudilika komhlaba eStoregga (ukudilika komhlaba) kunye neChicxulub, Chesapeake Bay, kunye neempembelelo zemeteorite zase-Eltanin.

Yenzeka njani i-megatsunami?

Itsunami enkulu yitsunami eneamplitude yokuqala (ubude) elinganiswa ngamashumi, amakhulu, okanye amawaka eemitha. Iitsunami ezinkulu ziyiklasi eyahlukileyo yeziganeko kuneetsunami zendabuko kwaye zibangelwa iindlela ezahlukeneyo.

Iitsunami eziqhelekileyo zisisiphumo sokushukuma komgangatho wolwandle ngenxa yeetectonic zepleyiti.. Iinyikima ezinamandla zisenokubangela ukuba umgangatho wolwandle uhambe amashumi eemitha, nto leyo enokuthi ishukumise intsika yamanzi ngaphezulu, nto leyo ebangela ukuvela kweetsunami. Iitsunami zesiNtu zinemiphakamo emincinci kakhulu yamaza elwandle kwaye azibonakali elwandle, kunye nokudumba okuncinci kuphela malunga ne-30 cm (12 ngo) ngaphezulu komphezulu wolwandle oqhelekileyo.

emanzini anzulu, itsunami inokuphumela emazantsi enqanawe ngaphandle kokuba abasebenzi baqaphele. Xa ifika emhlabeni, ukuphakama kwamaza etsunami yemveli inyuka ngokukhawuleza njengoko umgangatho wolwandle uthambeka kwaye umzantsi wamaza utyhala intsika yamanzi phezulu. Iitsunami zemveli, kwanazo zinxulunyaniswa nezona nyikima zinamandla, azifikeleli kubude obungaphezulu kwe-30 m.

Ngokwahlukileyo koko, iitsunami ezinkulu zibangelwa kukudilika komhlaba okukhulu kunye nezinye iziganeko ezichaphazela amanzi amaninzi. Oku kuquka imeko yeemeteors ezibetha ulwandle. Iinyikima zangaphantsi kwamanzi okanye ukuqhuma kwentaba-mlilo akuqhelekanga ukuvelisa iitsunami ezinkulu kangako, kodwa ukudilika komhlaba okubangelwa ziinyikima kufuphi namanzi kuba kubangela ukufuduka okukhulu. Ukuba kukho ukudilika komhlaba okanye ukothuka kumanzi alinganiselweyo, njengoko kwenzeka eVajont Dam (1963) naseLituya Bay (1958), amanzi asenokungasasazeki kwaye elinye okanye amaza amaninzi abe makhulu kakhulu.

Enye indlela yokubona umahluko kukuba iitsunami eziqhelekileyo zibangelwa kukutshintsha kolwandle., njengokutyhala umzantsi we-emele enkulu yamanzi ukuya kwindawo yokuphuphuma, okubangela ukuba amanzi "atyibilike" macala omabini. Kulo mzekeliso, itsunami enkulu ifana nokuwisa ilitye elikhulu kwelinye icala lebhafu ukusuka kwindawo ephakamileyo, libangele ukuba amanzi atshize kwaye aphuphume kwelinye icala.

Iitsunami ezinkulu ngamanye amaxesha zibizwa ngokuba ziindawo eziphakamileyo ezimbini: ukuphakama kwamaza ngokwawo (kumanzi avulekileyo) kunye nokuphakama kokunyuka kwawo xa ifika emhlabeni, enokuba ngamaxesha amaninzi aphezulu ngokuxhomekeke kwindawo.

Iziphumo kunye nobungozi

Kuphononongo olunikezelwe nguMbutho weTsunami kwi-1999, iindlela ezibangele i-tsunami enkulu yesiganeko saseLitua Bay zahlaziywa. Imodeli yaphuhliswa kakhulu kwaye yatshintshwa kwisifundo sesibini ngo-2010.

Nangona inyikima ebangele i-tsunami enkulu kukholelwa ukuba yayinamandla kakhulu, isenokungabi yiyo yodwa igalelo elisekelwe kumlinganiselo wokuphakama kwamaza. Amanzi echibi, ukudilika komhlaba, okanye inyikima ngokwayo ayizange ibe namandla ngokwaneleyo ukubangela itsunami enkulu, nangona ezi zisenokuba zinegalelo.

Kunoko, iitsunami ezinkulu zibangelwa yindibaniselwano yeziganeko ezilandelelanayo ngokukhawuleza. Esona siganeko siphambili seza ngendlela yomothuko omkhulu wequbuliso, xa malunga ne-40 yezigidi zeeyubhiki zeemitha zelitye elingamakhulu eemitha ngaphezulu kwetheku laqhekezwa yinyikima kwaye "phantse ngokupheleleyo" yakhutshwa kwithambeka. I-rockfall nayo yabangela ukuba umoya "ungene" ngenxa yeziphumo ze-viscous, eziye zandisa umthamo wokufuduka kwaye zichaphazela ngakumbi intlenga esezantsi kwe-bay, ukudala i-crater enkulu. Uphononongo lugqibe ngelithi:

• Ulwandle oluziimitha ezingama-524 kwintloko yechweba ngoJulayi 1,720, 9., kunye namaza alandelayo ecaleni komzimba omkhulu weLituya Bay, ayebangelwa ubukhulu becala sisilayidi samatye amakhulu. Amatye eGilbert Bay kwintloko yeLituya Bay, ebangelwa yintshukumo eguquguqukayo yomhlaba ecaleni kweFairweather Fault.

Ndiyathemba ukuba ngolu lwazi unokufunda ngakumbi malunga ne-megatsunami kunye neempawu zayo.