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
考研
The Earthquake Forecasts the New Progress of Aspect An accidental discovery has brought earthquake scientists one step close
The Earthquake Forecasts the New Progress of Aspect An accidental discovery has brought earthquake scientists one step close
admin
2013-04-03
26
问题
The Earthquake Forecasts the New Progress of Aspect
An accidental discovery has brought earthquake scientists one step closer to being able to predict earthquakes. As part of an effort to measure underground changes caused by shifts in barometric pressure, a team of researchers found that increases in subterranean pressure preceded earthquakes along California’s San Andreas Fault by as much as 10 hours. If follow-up tests advance the findings, earthquake scientists may eventually be able to provide a few hours’ notice for people to find safe haven prior to quakes. "Predicting earthquakes is the final goal for earthquake scientists," says Feng-lin Niu, the research team’s lead author and a Rice University earthquake scientist. "This is a start."
Reporting in the July 10 edition of the journal Nature, researchers used a high-tech equivalent of a stereo speaker lowered into a bore hole near Parkfield, Calif. , a half-mile deep and five yards from a measuring device. For two months beginning in late 2005, researchers transmitted pulse signals three times per second, from the speaker to the measuring device, calculating travel time between the two stations. Surprised scientists learned the seismic waves slowed dramatically on only two occasions: two hours prior to a magnitude-1 quake, and a startling 10 hours before a magnitude-3 quake.
The research team theorizes that the immense amount of pressure building along the fault causes small cracks within the rock during the final hours before an earthquake, increasing rock density and slowing the transmission signals. "The more cracks you have, the slower the seismic velocity," says study coauthor Paul Silver, a geophysicist with the Carnegie Institution of Washington. Still unknown is whether there is any significance to the fact that the magnitude-3 quake had a much longer pre-seismic signal than the lower-magnitude quake, or whether it was simply because its magnitude was larger and its center closer to the sensors.
If scientists can flesh out the new findings during future earthquakes—a two-year study at the same seismically active location begins this September—it could form the basis of a vastly improved early-warning system for quakes. Current earthquake-warning systems give just a few seconds’ notice because they detectonly P-waves, the fast-moving seismic waves that precede the more destructive waves released during a quake. Upgrading to a seismic stress meter, however, is still a long way off. "To use this for earthquake prediction, you need to know the precursor waves have a physical basis (that is, increased pressure and a pending quake) and that it’s repeatable (with a larger sample size of quakes)," Niu says. He also hopes to test whether the stress signals would still be detectable on a larger scale, with the two sensors spaced more than a few yards apart.
Except a major effort to drill multiple, half-mile-deep bore holes along fault lines, researchers would also need to develop a surface-based detection system capable of filtering out temperature swings, precipitation and other "noise" that could confuse their seismic readings. Says Silver, "we obviously have more work to do, but we’re certainly encouraged because this is what people are looking for."
From this passage, we can infer that the author______.
选项
A、holds that it is impossible to predict an earthquake
B、is very surprised about this discovery
C、thinks that scientists could do better
D、thinks this discovery is very important for earthquake prediction
答案
D
解析
观点态度题。[A]错误,作者在文中说到这次发现推进了地震预测的研究,并未提及预测地震是不可能的;[B]错误,对此发现表示惊讶的是科学家,因为这一发现并非他们的最初研究目的,文中没有提及作者的态度.[C]错误,作者只是描述了科学家的新发现,并不是批评他们之前做得不够,也没有表达任何不满;作者认为这一发现对于地震预报而言是非常重要的,因为文章开篇就提到它将该研究又向前推进了一步,正确答案为[D]。
转载请注明原文地址:https://kaotiyun.com/show/mDd4777K
0
考研英语一
相关试题推荐
Inthefollowingtext,somesentenceshavebeenremoved.ForQuestions41-45,choosethemostsuitableonefromthelist(A、B、C、
Inthefollowingtext,somesentenceshavebeenremoved.ForQuestions41-45,choosethemostsuitableonefromthelist(A、B、C、
StephenColbert’sperformanceattheWhiteHouseCorrespondentsDinnerninedaysagohasalreadycreatedadebateoverpolitics,
Everybodyloathesit,buteverybodydoesitArecentpollshowedthat20%ofAmericanshatethepractice.Itseemssoarbitrary,
GregFocker,playedbyBenStiller,representsagenerationofAmericankids(1)_____inthe1980sonthephilosophythatanyac
(46)Itmustbestressedthatacharacteristicaspectofthepresenttimeisthatscienceisexercisingadecisiveinfluenceont
Overthelast20years,energysystemsandserviceshaveexpanded.Californianowmeetsitsenergyneedsusingavarietyofsour
Accordingtothepassage,jobsontheproductionslineareusually______.RobertTheobaldbelievesthatpermanentunemployment
AllU.S.nuclearweaponsproductionfacilitiesarepresentlycloseddown,andifthevariousagreementsareadheredto,thosefa
SomeoftheconcernssurroundingTurkey’sapplicationtojointheEuropeanUnion,tobe(1)_____onbytheEU’sCouncilofMinis
随机试题
巨大胎儿经阴道分娩的常见并发症不包括()
下列保险费用项目中,属于规费中的社会保障费的有()。
报检单位在按有关规定办理报检,并提供抽样检验检疫的各种条件后,有权要求检验检疫机构在( )内完成检验检疫工作,并出具证明文件。[2006年第一次考试真题]
记名股票的特点包括()。Ⅰ.股东权利归属于记名股东Ⅱ.可以一次或分次缴纳出资Ⅲ.转让相对复杂或受限制Ⅳ.便于挂失,相对安全
为了避免审计报告被用于非预定目的,注册会计师可以在审计报告的审计意见段之后,增加说明段说明以下内容()。
商纣立为太子案“帝乙长子曰微子启,启母贱,不得嗣。少子辛,辛母正后,辛为嗣。帝乙崩,子辛立,是为帝辛,天下谓之纣。”——《史记.殷本纪》嫡长子继承制的含义及意义。
Astheunemploymentratesitsatjust3.7%,employersaregettingsodesperatefortalentthatthey’rethrowinghiringparties
某公司在项目执行过程中,对项目需求进行收集分析,并形成正式的项目文档,并由客户签字确认,但在交货时发现,实际产品与客户的要求大相径庭,客户拒绝付款。经调查研究发现,需求来源和低层需求实现不完全匹配,这最可能是在()方面出了问题。
下列关于光以太网在宽带城域网应用的描述中,错误的是()。
FiveCommonMistakesinConversationsandTheirSolutionsI.NotlisteningA.Problem:mostpeople【T1】______【T1】______—waite
最新回复
(
0
)