A boy stands amid the rubble of his home after a major earthquake in Santiago February 27, 2010. Chile has called of next week's double bill of friendlies against Costa Rica and North Korea after the massive earthquake which hit the country.(Agencies)
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The huge earthquake that struck off the coast of Chile belongs to an "elite class" of mega earthquakes, experts said, and is similar to the 2004 Indian Ocean temblor that triggered deadly tsunami waves. The magnitude-8.8 quake was a type called a "megathrust," considered the most powerful earthquake on the planet. Megathrusts occur when one tectonic plate dives beneath another. Saturday's tremor unleashed about 50 gigatons of energy and broke about 340 miles of the fault zone, according to the US Geological Survey's National Earthquake Information Center. The quake's epicenter was offshore and occurred about 140 miles north of the largest earthquake ever recorded — a magnitude-9.5 that killed about 1,600 people in Chile and scores of others in the Pacific in 1960. "It's part of an elite class of giant earthquakes," said USGS geologist Brian Atwater. If the magnitude holds, it will tie with the 1906 offshore Ecuador quake as the fifth largest since 1900. "We call them great earthquakes. Everybody else calls them horrible," said USGS geophysicist Ken Hudnut. "There's only a few in this league." The Chile quake was smaller than the Sumatra quake of 2004, a magnitude-9.1 and was not expected to be anything nearly as destructive. That quake and ensuing tsunami killed 230,000 people. Another difference is that the Chile quake triggered tsunami warnings hours ahead of time in Hawaii and Pacific islands, allowing people time to flee to higher ground. In 2004, there was little measuring technology in place to warn Indian Ocean countries about incoming killer waves. More than 100 aftershocks measuring magnitude-5 or larger rattled Chile throughout the day. So far, the quake death toll has surpassed 300 — a number that will likely rise. Several more died when tsunami waves swamped an island off the country's coast. Chile is no stranger to violent jolts. In fact, USGS geophysicist Ross Stein called the country an "earthquake hatchery." Thirteen temblors of magnitude 7 or larger have hit Chile since 1973. (Read by Renee Haines. Renee Haines is a multimedia journalist at the China Daily Web site.) |
智利附近海域日前遭遇特大地震,據(jù)專家介紹,此次地震屬于超級(jí)大地震中的“頂尖級(jí)別”,與2004年那場(chǎng)引發(fā)致命海嘯的印度洋地震不相上下。 智利發(fā)生的這場(chǎng)里氏8.8級(jí)大地震屬于“大逆沖型地震”,只有當(dāng)一個(gè)地殼板塊俯沖至另一板塊的下方時(shí)才會(huì)發(fā)生,被認(rèn)為是地球上威力最強(qiáng)的地震。據(jù)美國(guó)地質(zhì)調(diào)查局國(guó)家地震信息中心統(tǒng)計(jì),上周六發(fā)生于智利的地震釋放了大約500億噸能量,而且造成約340英里長(zhǎng)的斷層帶破裂。 此次地震的震中位于海上,位于史上規(guī)模最大的、發(fā)生于1960年的智利9.5級(jí)地震的震中以北140英里處。這場(chǎng)地震造成約1600人遇難,并造成太平洋海域的很多人喪生。 美國(guó)地質(zhì)調(diào)查局的地質(zhì)學(xué)家布萊恩?阿特沃特說(shuō):“這場(chǎng)地震屬于超級(jí)大地震中的頂尖等級(jí)?!?/p> 如果按照震級(jí)來(lái)劃分,這次地震將與1906年發(fā)生于厄瓜多爾附近海域的地震并列為1900年以來(lái)的第五大地震。 美國(guó)地質(zhì)調(diào)查局的地球物理學(xué)家肯?赫德納特說(shuō):“我們稱它們?yōu)槌?jí)地震,它們的力量十分可怕。這種級(jí)別的地震不是很多?!?/p> 與2004年蘇門答臘島發(fā)生的里氏9.1級(jí)地震相比,此次智利地震的規(guī)模相對(duì)較小,據(jù)估計(jì)其破壞性也相去甚遠(yuǎn)。2004年的蘇門答臘島地震及其引發(fā)的海嘯導(dǎo)致23萬(wàn)人喪生。另一個(gè)區(qū)別在于,提前數(shù)小時(shí)發(fā)布的海嘯預(yù)警讓夏威夷和太平洋島嶼的居民有了充分的逃命時(shí)間。 而2004年,由于勘測(cè)技術(shù)有限,無(wú)法向印度洋國(guó)家發(fā)出大規(guī)模海嘯襲擊的預(yù)警。 當(dāng)天,智利還發(fā)生了100多次里氏5級(jí)或更大級(jí)別的余震。截至目前,地震死亡人數(shù)已超過(guò)300,而這一數(shù)字還有可能會(huì)繼續(xù)上升。地震引發(fā)的海嘯還席卷了智利附近海域的一個(gè)島嶼,造成數(shù)人死亡。 智利是個(gè)大地震多發(fā)的國(guó)家。美國(guó)地質(zhì)調(diào)查局地球物理學(xué)家羅斯?斯坦稱其為“地震孵化器”。自1973年以來(lái),智利共發(fā)生了13次里氏7級(jí)或更高級(jí)別的地震。 相關(guān)閱讀 奧巴馬就海地發(fā)生強(qiáng)烈地震發(fā)表講話中英文對(duì)照 關(guān)注海地地震 學(xué)習(xí)相關(guān)詞匯 克林頓出任聯(lián)合國(guó)印度洋海嘯救災(zāi)特使 (中國(guó)日?qǐng)?bào)網(wǎng)英語(yǔ)點(diǎn)津 Julie 編輯蔡姍姍) |
Vocabulary: temblor:earthquake(地震) tectonic plate:地層,地殼板塊 fault zone:斷層 swamp:to flood or drench with water or the like(淹沒(méi),覆沒(méi)) |