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
2024-05-30
9
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] It can be learnt from the passage that the current method of earthquake prediction______.
选项
A、provides more accurate data than the new one
B、costs less than the new one
C、costs more than the new one
D、warns people only a few seconds before the earthquake
答案
D
解析
根据题干关键词current method,earthquake prediction定位到第四段第二句:Current earthquake-warning systems give just a few seconds’ notice because they detect only P-waves,the fast-moving seismic waves that precede the more destructive waves released during a quake.可推知目前的预测
转载请注明原文地址:https://tihaiku.com/zcyy/3612231.html
相关试题推荐
Thediscoverythatlanguagecanbeabarriertocommunicationisquicklymade
Thediscoverythatlanguagecanbeabarriertocommunicationisquicklymade
Thediscoverythatlanguagecanbeabarriertocommunicationisquicklymade
TheAfricanancestorsoftoday’sblackAmericanswerebroughttotheU.S.a
TheAfricanancestorsoftoday’sblackAmericanswerebroughttotheU.S.a
TheAfricanancestorsoftoday’sblackAmericanswerebroughttotheU.S.a
TheAfricanancestorsoftoday’sblackAmericanswerebroughttotheU.S.a
Awayfromtheirprofession,_____________________(科学家并不天生就比其他人更讲道德).scientists
Shebroughtupthewater,____________(在每一个楼梯拐弯处停下来歇口气).stoppingateachlandin
[originaltext]Goodmorningstudents.ThisclassIbroughttwobooksthatI
随机试题
Ourape-menforefathershadnoobviousnaturalweaponsinthestruggle(1)___
SoapoperaisforTVwhatthepopularnovelisforbooks.It’seasytounder
WomenprisonersinBritain______[br][originaltext]InBritain,ffyouar
制剂的生物利用度应该用__________、__________、_______
1.题目:《电视机旁的一家子》 2.内容: 组织学生进行写作练习,命题作
属于固体废弃物减量化处理方法的是()。A、焚烧、热解、填埋 B、焚烧、填埋
属于苯二氮类镇静催眠药的是A.奥沙西泮 B.地西泮 C.替马西泮 D.艾司
某人工作辛劳而又喜欢业余上网,他个人用户中有396元,请问他最可能选择上述三
A.微囊 B.缓释膜剂 C.包合物 D.前体药物制剂 E.固体分散体利用
水的自净作用有多种形式,除了( )。A.稀释、扩散 B.吸附沉降 C.生物
最新回复
(
0
)