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
20
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 new way to predict earthquake might work by______.
选项
A、measuring barometric pressure
B、measuring underground pressure
C、studying pre-seismic signals
D、detecting seismic waves
答案
B
解析
根据题干关键词new way,predict earthquake,work定位到第一段第二句:As part of an unrelated 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
转载请注明原文地址:https://tihaiku.com/zcyy/2995963.html
相关试题推荐
Awayfromtheirprofession,_____________________(科学家并不天生就比其他人更讲道德).scientists
[originaltext]Goodmorningstudents.ThisclassIbroughttwobooksthatI
Ifsomeoneaccidentallystepsonyourtoe,ithurts.Butdoesithurtmore
Ifsomeoneaccidentallystepsonyourtoe,ithurts.Butdoesithurtmore
Ifsomeoneaccidentallystepsonyourtoe,ithurts.Butdoesithurtmore
Anaccidentaldiscoveryhasbroughtseismologists(地震学家)onestepcloserto
Anaccidentaldiscoveryhasbroughtseismologists(地震学家)onestepcloserto
Anaccidentaldiscoveryhasbroughtseismologists(地震学家)onestepcloserto
JustliketheworkofEinstein,thenewdiscovery_______________(对于人类必定大有用处).
Thisfestivalwassetup______(纪念那个伟大的哲学家和教育家).Inmemoryofthatgreatphilos
随机试题
Virtuallyeverythingastronomersknownaboutobjectsoutsidethesolarsyste
中国位于亚洲东部,它是世界上人口最多的国家。中国是四大文明古国之一,地大物博,拥有茂密的森林、雄伟壮丽的瀑布、秀丽的湖泊、如利剑(sword)般直插云霄的
2015年,我国规模以上电子信息产业企业个数6.08万家,其中电子信息制造企业1
当企业积累的实耗工时统计资料比较多时,可将工时资料先进行适当的分组,然后再采用(
王某认为其所在地市公安局8月15日对其作出行政拘留行为侵犯其合法权益,他必须在(
从所给的四个选项中,选择最合适的一个填入问号处,使之呈现一定的规律性:
下列属于行业生命周期中成熟期的特点的是()。A.竞争压力小,企业规模小 B.
男,50岁。胃大部切除术后3天出血,阵发性腹痛、腹胀,无肛门排气,生命体征平稳。
女,30岁,已婚。放置宫内节育器2年,停经48天,少量阴道出血3天,突然右下腹剧
根据施工成本的过程控制方法,其控制要点有()。A.材料费的控制实行量价分离的方法
最新回复
(
0
)