首页
登录
职称英语
An accidental discovery has brought seismologists(地震学家) one step closer to
An accidental discovery has brought seismologists(地震学家) one step closer to
游客
2023-09-08
18
管理
问题
An accidental discovery has brought seismologists(地震学家) one step closer to being able to predict earthquakes. As part of an unrelated effort to measure underground changes caused by shifts in barometric pressure (大气压力), a team of researchers found that increases in subterranean pressure(地下压力) preceded earthquakes along California’s San Andreas Fault(断层) by as much as 10 hours. If follow-up tests advance the findings, seismologists may eventually be able to provide a few hours’ notice for people to find safe places prior to quakes.
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 temblor (地震), 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 co-author 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 epicenter 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 detect only 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 of{. Researchers hope 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.
Barring a major effort to drill multiple, half-mile-deep holes along fault lines, researchers would also need to develop a surface-based detection system capable of filtering out temperature swings and other "noise" that could confuse their seismic readings. [br] The passage mainly tells us about ______.
选项
A、the importance of predicting earthquakes
B、a new method to predict earthquakes
C、the great damages caused by earthquakes
D、a traditional method to predict earthquakes
答案
B
解析
根据题干关键词passage.tell定位到整篇原文,文章首句即点明了中心:An accidental discovery has brought seismologists one step closer to being able to predict earthquakes.由此可知本文主要介绍了一种可能会有效预测地震的新方法,故选B项。
转载请注明原文地址:https://tihaiku.com/zcyy/2995962.html
相关试题推荐
[originaltext]JoeSmithhadbeenbroughtupinanorphanage.Heenviedpeop
[originaltext]JoeSmithhadbeenbroughtupinanorphanage.Heenviedpeop
Fromaworldofsilence,deafpercussionistEvelynGlenniebroughtsomeof
Fromaworldofsilence,deafpercussionistEvelynGlenniebroughtsomeof
Fromaworldofsilence,deafpercussionistEvelynGlenniebroughtsomeof
Thediscoverythatlanguagecanbeabarriertocommunicationisquicklymade
TheAfricanancestorsoftoday’sblackAmericanswerebroughttotheU.S.a
TheAfricanancestorsoftoday’sblackAmericanswerebroughttotheU.S.a
TheAfricanancestorsoftoday’sblackAmericanswerebroughttotheU.S.a
TheAfricanancestorsoftoday’sblackAmericanswerebroughttotheU.S.a
随机试题
Chimp(黑猩猩)ShowHallmarkofHumanCulture,StudyFindsResearcher
1958年,一位日本人发明了方便面(instantnoodle)。虽然它没什么营养(nutrition)却因为美味并能遏制饥饿,所以在诞生后迅猛发展。
以下哪项不宜作为建筑物中水系统的水源?()A.盥洗排水 B.室外雨水 C
X公司为增值税一般纳税人,适用的增值税税率为13%,所得税采用资产负债表债务法核
根据《防范和处置非法集资条例》(国务院令第737号)等规定,下列说法正确的有(
在国内生产总值的定义中区分国内生产和国外生产,一般以()为标准。A.市民
驱绦虫,宜冷开水调服的药是A.槟榔B.苦楝皮C.榧子D.南瓜子E.使君子
圆盘某瞬时以角速度ω,角加速度α绕O轴转动,其上A、B两点的加速度分别为aA和a
牙周炎伴糖尿病的特征如下,除外A:易发生牙周脓肿 B:牙周手术愈合较差 C:
污染源通常是指向环境排放有害物质或对环境产生有害影响的( )。A.人员 B.
最新回复
(
0
)