首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
Eastern Quakes Can Trigger Big Shakes In the first week of November 2011, people in central Oklahoma experienced more than tw
Eastern Quakes Can Trigger Big Shakes In the first week of November 2011, people in central Oklahoma experienced more than tw
admin
2012-12-06
90
问题
Eastern Quakes Can Trigger Big Shakes
In the first week of November 2011, people in central Oklahoma experienced more than two dozen earthquakes. The largest, a magnitude 5.6 quake, shook thousands of fans in a college football stadium, caused cracks in a few buildings and rattled the nerves of many people who had never felt a quake before. Oklahoma is not an area of the country famous for its quakes. If you watch the news on TV, you see reports about all sorts of natural disasters —hurricanes, tornadoes, flooding and wildfires, to name a few. But the most dangerous type of natural disaster, and also the most unpredictable, is the earthquake.
Researchers at the U.S. Geological Survey estimate that several million earthquakes rattle the globe each year. That may sound scary, but people don’t feel many of the tremors because they happen in remote and unpopulated regions. Many quakes happen under the ocean, and others have a very small magnitude, or shaking intensity.
A magnitude 5.8 earthquake that struck central Virginia the afternoon of August 23, 2011, was felt from central Georgia to southeastern Canada. In many urban areas, including Washington, D.C., and New York City (Wall Street shown), people crowded the streets while engineers inspected buildings. Credit: Wikimedia/Alex Tabak
Scientists know about small, remote quakes only because of very sensitive electronic devices called seismometers. These devices detect and measure the size of ground vibrations produced by earthquakes. Altogether, USGS researchers use seismometers to identify and locate about 20,000 earthquakes each year.
Although earthquakes can happen anywhere in the world, really big quakes occur only in certain areas. The largest ones register a magnitude 8 or higher and happen, on average, only once each year. Such big ones typically occur along the edges of Earth’s tectonic plates.
Tectonic plates are huge pieces of Earth’s crust, sometimes many kilometers thick. These plates cover our planet’s surface like a jigsaw puzzle. Often, jagged edges of these plates temporarily lock together. When plates jostle and scrape past each other earthquakes occur. On average, tectonic plates move very slowly — about the same speed as your fingernails grow.
But sometimes earthquakes rumble through portions of the landscape far from a plate’s edges. Although less expected, these “mid-plate” tremors can do substantial damage. Some of the biggest known examples rattled the eastern half of the United States two centuries ago. Today, scientists are still puzzling over why the quakes occurred and when similar ones might occur.
The earthquake that hit the eastern half of the United States two centuries ago is the biggest "mid-plate" one in history.
选项
A、Right
B、Wrong
C、Not mentioned
答案
C
解析
转载请注明原文地址:https://www.kaotiyun.com/show/vLQd777K
本试题收录于:
职称英语理工类C级题库职称英语分类
0
职称英语理工类C级
职称英语
相关试题推荐
MenTooMaySufferFromDomesticViolenceNearlythreein10menhaveexperiencedviolenceatthehandsofanintimatepartn
MenTooMaySufferFromDomesticViolenceNearlythreein10menhaveexperiencedviolenceatthehandsofanintimatepartn
TryingtoFindaPartnerOneofthemoststrikingfindingsofarecentpollintheUKisthatofthepeopleinterviewed,one
Canadalkea:WhataGreatPlaceforYoutoShopTherearemanydifferentstoresthatpeoplegotoinordertobuyvarioushou
Itisobviousthatithasbeentoolatetotakeaction.
HealthyFoodStreetsellers,particularlyindevelopingcountries,supplylargeamountsoffood(51)peopleonlowincomes.Thi
Butintheendheapprovedofourproposal.
Recentpressureatworkmayaccountforhisbehavior.
Thecityhasdecidedtodoawaywithalltheoldbuildingsinitscentre.
随机试题
风湿热,阿司匹林每日治疗剂量是
人民法院审理行政案件,参照________、要根据________、________、________、________的规章以及省、自治区、直辖市和省、自治区人民政府所在地的市和国务院批准的较大的市的人民政府根据法律和行政法规制定、发布的规章。
A、Tothebank.B、Toabookstore.C、Toashoestore.D、Tothegrocer’s.D
婴儿期"生理性贫血"一般在什么时候出现
A.益火补土B.培土制水C.抑木扶土D.泻南补北E.佐金平木根据五行相生规律确定的治则是
从安全生产角度解释,危险源是指可能造成人员伤害、疾病、财产损失、作业环境破坏或其他损失的()。
非同一控制下的企业合并,以发行权益性证券作为合并对价的,发行权益性证券相关的佣金、手续费等应计入合并成本。()
如果从伦理的角度着眼,两极分化是一种悲剧性的社会现实。面对落入破产者行列的许多小生产者和劳动者,我们不能不寄予深切的同情。但是从生产力的角度着眼,两极分化是商品经济的价值规律发生作用后的必然经济结果,它发挥着约束和激励的功能,使人力资源和物质资源都趋于更合
对于实数x>0,定义对数函数Inx=依此定义试证:(1)=一lnx(x>0);(2)ln(xy)=lnx+Iny(x>0,y>0).
【T1】Whenyouareinthebusinessofsendingspacecrafttootherplanets,itisprobablywisetodoeverythingyoucantokeepyo
最新回复
(
0
)