{"id":646,"date":"2020-02-19T10:57:52","date_gmt":"2020-02-19T10:57:52","guid":{"rendered":"https:\/\/extraslovensko.sk\/spravy\/?p=646"},"modified":"2020-02-19T10:57:52","modified_gmt":"2020-02-19T10:57:52","slug":"geotermalny-zdroj-tepla-v-antarktide","status":"publish","type":"post","link":"https:\/\/extraslovensko.sk\/spravy\/geotermalny-zdroj-tepla-v-antarktide\/","title":{"rendered":"Geoterm\u00e1lny zdroj tepla v Antarktide"},"content":{"rendered":"

\u0160t\u00fadia NASA z roku 2017 dod\u00e1va d\u00f4kazy, \u017ee geoterm\u00e1lny zdroj tepla naz\u00fdvan\u00fd oblak pl\u00e1\u0161\u0165a le\u017e\u00ed hlboko pod antarktickou krajinou Marie Byrd Land<\/strong>, \u010do vysvet\u013euje niektor\u00e9 topenia, ktor\u00e9 vytv\u00e1raj\u00fa jazer\u00e1 a rieky pod \u013eadovou pokr\u00fdvkou. Aj ke\u010f zdroj tepla nie je novou alebo rast\u00facou hrozbou pre \u013eadov\u00fa pokr\u00fdvku Z\u00e1padnej Antarkt\u00eddy, m\u00f4\u017ee to pom\u00f4c\u0165 vysvetli\u0165, pre\u010do sa \u013eadov\u00e1 pokr\u00fdvka r\u00fdchlo zr\u00fatila v skor\u0161ej dobe r\u00fdchlych klimatick\u00fdch zmien a pre\u010do je dnes tak nestabiln\u00e1. Stabilita \u013eadovej pokr\u00fdvky \u00fazko s\u00favis\u00ed s t\u00fdm, ko\u013eko vody ma\u017ee zdola, \u010do umo\u017e\u0148uje \u013eah\u0161ie k\u013azanie \u013eadovcov.
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\nPochopenie zdrojov a bud\u00facnosti meltwater pod Z\u00e1padnou Antarkt\u00eddou je d\u00f4le\u017eit\u00e9 pre odhad r\u00fdchlosti, akou m\u00f4\u017ee by\u0165 \u013ead straten\u00fd v oce\u00e1ne v bud\u00facnosti. Z\u00e1kladn\u00fd kame\u0148 Antarkt\u00eddy je priviazan\u00fd k riekam a jazer\u00e1m, z ktor\u00fdch najv\u00e4\u010d\u0161ie je ve\u013ekos\u0165 jazera Erie. Mnoh\u00e9 jazer\u00e1 sa r\u00fdchlo vyp\u013a\u0148aj\u00fa a odtokuj\u00fa, \u010do n\u00fati \u013eadov\u00fa plochu tis\u00edce metrov nad nimi, aby st\u00fapali a klesali a\u017e o 20 metrov (6 metrov). N\u00e1vrh umo\u017e\u0148uje vedcom odhadn\u00fa\u0165, kde a ko\u013eko vody mus\u00ed existova\u0165 na z\u00e1kladni. Asi pred 30 rokmi vedec z University of Colorado Denver navrhol, \u017ee teplo z pl\u00e1\u0161\u0165a pl\u00e1\u0161\u0165a pod zemou Marie Byrd Land by mohlo vysvetli\u0165 region\u00e1lnu sope\u010dn\u00fa aktivitu a topografick\u00fa kupolov\u00fa funkciu. Tento koncept podporuje ned\u00e1vne seizmick\u00e9 zobrazovanie.
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\n\"Geoterm\u00e1lny<\/p>\n

\nKe\u010f v\u0161ak H\u00e9l\u00e8ne Seroussi z Jet Propulsion Laboratory v Kalifornii v Pasadene v Kalifornii prv\u00fdkr\u00e1t po\u010dula tento n\u00e1pad, \u201emyslela som si, \u017ee je to \u0161ialen\u00e9,\u201c povedala. \u201eNevidel som, ako by sme mohli ma\u0165 tak\u00e9 mno\u017estvo tepla a st\u00e1le na \u0148om ma\u0165 \u013ead.\u201c Seroussi a Erik Ivins zo spolo\u010dnosti JPL s nieko\u013ek\u00fdmi priamymi meraniami existuj\u00facimi pod \u013eadom dospeli k z\u00e1veru, \u017ee najlep\u0161\u00edm sp\u00f4sobom, ako \u0161tudova\u0165 my\u0161lienku oblaku pl\u00e1\u0161\u0165a, bolo numerick\u00e9 modelovanie. Pou\u017e\u00edvali model \u013eadov\u00fdch pl\u00e1tov (ISSM), numerick\u00e9 zobrazenie fyziky \u013eadovcov vyvinut\u00e9 vedcami z JPL a Kalifornskej univerzity v Irvine. Seroussi vylep\u0161il ISSM tak, aby zachyt\u00e1val pr\u00edrodn\u00e9 zdroje vykurovania a prenosu tepla z mrazu, topenia a tekutej vody; trenie; a \u010fal\u0161ie procesy. Aby sa zaistilo, \u017ee model je realistick\u00fd, vedci vych\u00e1dzali z pozorovan\u00ed zmien v nadmorskej v\u00fd\u0161ke povrchu \u013eadovej pokr\u00fdvky, ktor\u00e9 uskuto\u010dnila satelitn\u00e1 sie\u0165 IceSat agent\u00fary NASA a leteck\u00e1 kampa\u0148 IceBridge. \u201eTieto miesta silne obmedzuj\u00fa povolen\u00e9 r\u00fdchlosti tavenia – to, \u010do sme chceli predv\u00edda\u0165,\u201c povedal Ivins.
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\nPreto\u017ee umiestnenie a ve\u013ekos\u0165 mo\u017en\u00e9ho oblaku pl\u00e1\u0161\u0165a neboli zn\u00e1me, otestovali cel\u00fd rad fyzik\u00e1lnych mo\u017enost\u00ed pre viacero parametrov a vytvorili desiatky r\u00f4znych simul\u00e1ci\u00ed. Zistili, \u017ee tok energie z pl\u00e1\u0161\u0165a pl\u00e1\u0161\u0165a nesmie by\u0165 vy\u0161\u0161\u00ed ako 150 miliwattov na meter \u0161tvorcov\u00fd. Pre porovnanie, v regi\u00f3noch USA bez sope\u010dnej aktivity je tepeln\u00fd tok zo zemsk\u00e9ho pl\u00e1\u0161\u0165a 40 a\u017e 60 miliwattov. Pod n\u00e1rodn\u00fdm parkom Yellowstone, zn\u00e1mym geoterm\u00e1lnym hor\u00facim miestom je teplo zospodu okolo 200 miliwattov na meter \u0161tvorcov\u00fd v priemere po celom parku, hoci jednotliv\u00e9 geoterm\u00e1lne prvky, ako s\u00fa napr\u00edklad gejz\u00edry, s\u00fa ove\u013ea hor\u00face.
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\nSimul\u00e1cie Seroussiho a Ivinsovej, pri ktor\u00fdch sa pou\u017eil tepeln\u00fd tok vy\u0161\u0161\u00ed ako 150 miliwattov na meter \u0161tvorcov\u00fd, preuk\u00e1zali pr\u00edli\u0161 ve\u013ek\u00fa teplotu topenia, aby boli kompatibiln\u00e9 s \u00fadajmi o vesm\u00edre, s v\u00fdnimkou jedn\u00e9ho miesta: oblas\u0165 vn\u00fatrozemia Rossov\u00e9ho mora, ktor\u00e1 je zn\u00e1ma intenz\u00edvnym tokom vody. T\u00e1to oblas\u0165 si vy\u017eadovala tepeln\u00fd tok najmenej 150 – 180 miliwattov na meter \u0161tvorcov\u00fd, aby s\u00fahlasila s pozorovaniami. Seizmick\u00e9 zobrazovanie v\u0161ak uk\u00e1zalo, \u017ee teplo pl\u00e1\u0161\u0165a v tejto oblasti sa m\u00f4\u017ee dosta\u0165 do \u013eadovej pokr\u00fdvky trhlinou, to znamen\u00e1 zlomeninou zemskej k\u00f4ry, ako sa vyskytuje v africkom \u00fadol\u00ed Great Rift Valley.
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\nPl\u00e1\u0161\u0165ov\u00e9 oblaky s\u00fa pova\u017eovan\u00e9 za \u00fazke pr\u00fady hor\u00facej skaly st\u00fapaj\u00facej cez zemsk\u00fd pl\u00e1\u0161\u0165 a \u0161\u00edriace sa ako hr\u00edbov\u00e1 \u010diapka pod k\u00f4rou. Vztlak materi\u00e1lu, z ktor\u00e9ho sa \u010diasto\u010dne roztav\u00ed, sp\u00f4sobuje, \u017ee sa k\u00f4ra vybuchne nahor. Te\u00f3ria pl\u00e1\u0161\u0165ov\u00fdch oblakov bola navrhnut\u00e1 v 70-tych rokoch na vysvetlenie geoterm\u00e1lnej aktivity, ktor\u00e1 sa vyskytuje \u010faleko od hranice tektonickej platne, ako je Havaj a Yellowstone. <\/p>\n

Obl\u00fak pl\u00e1\u0161\u0165a Marie Byrd Land sa vytvoril pred 50 a\u017e 110 mili\u00f3nmi rokov, d\u00e1vno predt\u00fdm, ako vznikla \u013eadov\u00e1 pokr\u00fdvka Z\u00e1padn\u00e9ho Antarkt\u00eddy. Na konci poslednej doby \u013eadovej asi pred 11 000 rokmi, \u013eadov\u00e1 pokr\u00fdvka pre\u0161la obdob\u00edm r\u00fdchleho a trval\u00e9ho \u00fabytku \u013eadu, ke\u010f zmeny v glob\u00e1lnom po\u010das\u00ed a st\u00fapaj\u00faca hladina mora tla\u010dili tepl\u00fa vodu bli\u017e\u0161ie k \u013eadovej pokr\u00fdvke, rovnako ako sa to deje dnes. Seroussi a Ivins nazna\u010duj\u00fa, \u017ee pl\u00e1\u0161\u0165 pl\u00e1\u0161\u0165a by mohol u\u013eah\u010di\u0165 tento druh r\u00fdchlych str\u00e1t. Ich pr\u00edspevok s n\u00e1zvom \u201eVplyv oblaku z\u00e1padn\u00e9ho antarktick\u00e9ho pl\u00e1\u0161\u0165a na z\u00e1kladn\u00e9 podmienky \u013eadovej pokr\u00fdvky\u201c bol publikovan\u00fd v \u010dasopise Journal of Geofyzical Research: Solid Earth.<\/p>\n

Na kontinente je tie\u017e hist\u00f3ria n\u00e1silia. Pod\u013ea jedn\u00e9ho nepotvrden\u00e9ho pr\u00edbehu uverejnen\u00e9ho v kanadskej geografii vedec pracuj\u00faci na ruskej stanici Vostok v roku 1959 vyhodil po tom, \u010do prehral \u0161achov\u00fa hru, a zavra\u017edil svojho s\u00fapera sekerou. (\u0160ach bol n\u00e1sledne zak\u00e1zan\u00fd z rusk\u00fdch antarktick\u00fdch z\u00e1kladn\u00ed.) Ned\u00e1vno v okt\u00f3bri 2018 rusk\u00fd vedec pracuj\u00faci v Antarkt\u00edde \u00fadajne bodol svojho kolegu po mo\u017enom nervovom zlyhan\u00ed.<\/div>\n","protected":false},"excerpt":{"rendered":"

\u0160t\u00fadia NASA z roku 2017 dod\u00e1va d\u00f4kazy, \u017ee geoterm\u00e1lny zdroj tepla naz\u00fdvan\u00fd oblak pl\u00e1\u0161\u0165a le\u017e\u00ed hlboko pod antarktickou krajinou Marie Byrd Land, \u010do vysvet\u013euje niektor\u00e9 topenia, ktor\u00e9 vytv\u00e1raj\u00fa jazer\u00e1 a rieky pod \u013eadovou pokr\u00fdvkou. Aj ke\u010f zdroj tepla nie je novou alebo rast\u00facou hrozbou pre \u013eadov\u00fa pokr\u00fdvku Z\u00e1padnej Antarkt\u00eddy, m\u00f4\u017ee to pom\u00f4c\u0165 vysvetli\u0165, pre\u010do sa […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5],"tags":[],"class_list":["post-646","post","type-post","status-publish","format-standard","hentry","category-exo-news"],"_links":{"self":[{"href":"https:\/\/extraslovensko.sk\/spravy\/wp-json\/wp\/v2\/posts\/646","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/extraslovensko.sk\/spravy\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/extraslovensko.sk\/spravy\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/extraslovensko.sk\/spravy\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/extraslovensko.sk\/spravy\/wp-json\/wp\/v2\/comments?post=646"}],"version-history":[{"count":0,"href":"https:\/\/extraslovensko.sk\/spravy\/wp-json\/wp\/v2\/posts\/646\/revisions"}],"wp:attachment":[{"href":"https:\/\/extraslovensko.sk\/spravy\/wp-json\/wp\/v2\/media?parent=646"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/extraslovensko.sk\/spravy\/wp-json\/wp\/v2\/categories?post=646"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/extraslovensko.sk\/spravy\/wp-json\/wp\/v2\/tags?post=646"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}