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
In 1971 researchers hoping to predict earthquakes in the short term by identifying precursory phenomena (those that occur a few
In 1971 researchers hoping to predict earthquakes in the short term by identifying precursory phenomena (those that occur a few
admin
2019-11-17
25
问题
In 1971 researchers hoping to predict earthquakes in the short term by identifying precursory phenomena (those that occur a few days before large quakes but not otherwise) turned their attention to changes in seismic waves that had been detected prior to earthquakes. An explanation for such changes was offered by "dilatancy theory," based on a well-known phenomenon observed in rocks in the laboratory: as stress builds, microfractures in rock close, decreasing the rock’s volume. But as stress continues to increase, the rock begins to crack and expand in volume, allowing groundwater to seep in, weakening the rock. According to this theory, such effects could lead to several precursory phenomena in the field, including a change in the velocity of seismic waves, and an increase in small, nearby tremors.
Researchers initially reported success in identifying these possible precursors, but subsequent analyses of their data proved disheartening. Seismic waves with unusual velocities were recorded before some earthquakes, but while the historical record confirms that most large earthquakes are preceded by minor tremors, these foreshocks indicate nothing about the magnitude of an impending quake and are indistinguishable from other minor tremors that occur without large earthquakes.
In the 1980s, some researchers turned their efforts from short-term to long-term prediction. Noting that earthquakes tend to occur repeatedly in certain regions, Lindh and Baker attempted to identify patterns of recurrence, or earthquake cycles, on which to base predictions. In a study of earthquake-prone sites along the San Andreas Fault, they determined that quakes occurred at intervals of approximately 22 years near one site and concluded that there was a 95 percent probability of an earthquake in that area by 1992. The earthquake did not occur within the time frame predicted, however.
Evidence against the kind of regular earthquake cycles that Lindh and Baker tried to establish has come from a relatively new field, paleoseismology. Paleoseismologists have unearthed and dated geological features such as fault scarps that were caused by earthquakes thousands of years ago. They have determined that the average interval between ten earthquakes that took place at one site along the San Andreas Fault in the past two millennia was 132 years, but individual intervals ranged greatly, from 44 to 332 years.
It can be inferred from the passage that one problem with using precursory phenomena to predict earthquakes is that minor tremors
选项
A、typically occur some distance from the sites of the large earthquakes that follow them
B、are directly linked to the mechanisms that cause earthquakes
C、are difficult to distinguish from major tremors
D、have proven difficult to measure accurately
E、are not always followed by large earthquakes
答案
E
解析
Inference
This question asks what can be inferred from certain information in the passage. The second paragraph explains two problems with using minor tremors to predict earthquakes. First, minor tremors provide no information about how large an impending earthquake will be. Second, the minor tremors that occur prior to a large earthquake are indistinguishable from other minor tremors. Thus, it can be inferred that minor tremors sometimes occur when no large earthquake follows.
A The passage does not mention the distance between minor tremors and ensuing earthquakes.
B The passage implies that minor tremors sometimes occur without an ensuing earthquake, so the phenomena are most likely not directly linked.
C The passage suggests no difficulty in distinguishing between minor tremors and major tremors.
D The passage does not mention any difficulties in the measurement of minor tremors.
E Correct. The passage indicates that minor tremors occurring prior to a large earthquake are indistinguishable from minor tremors that are not followed by large earthquakes. So the fact that minor tremors are not always followed by large earthquakes, together with the inability to distinguish between those that are and those that are not, poses a problem for a ny attempt to predict large earthquakes on the basis of this type of precursory phenomena.
The correct answer is E.
转载请注明原文地址:https://jikaoti.com/ti/s6dYFFFM
本试题收录于:
GMAT VERBAL题库GMAT分类
0
GMAT VERBAL
GMAT
相关试题推荐
Theopeningbetweentherockswasverynarrow,buttheboysmanagedto_________through.
HarrietBeecherStowehadpouredherheartintoheranti-slaverybook,"UncleTom’sCab-in".Butneithershenorherfirstpubl
TheUnitedStates【C1】______alargepartoftheNorthAmericancontinent.ItsneighborsareCanada【C2】______thenorth,andMexico
AstheNationalParkServicecelebratesits100thanniversary(周年纪念),PresidentBarackObamahasannouncedtheestablishmentof
Extensivenewstudiessuggestthatdieworldhasmadeextraordinaryprogressinreducingpovertyinrecentdecades.Theresearch
TheCalifornialawmakersvotedThursdaytoraisethelegalagetobuytobaccoproductsfrom18to21.Themeasureispartofal
Scientistssaidtheyhavefoundevidenceofagiantplanetfaroutinoursolarsystem.Inastatement,theCaliforniaInstitute
Imagineaschoolthatexpecteditsstudentstobecomeliteratewithoutanyformalinstruction.Mostparentswouldbealarmedby
Indianenergyofficialshavebeenseekingwaystouseless-importedoiltoprovideenergy.
Belowisapictureshowingayoungwomanwhoworksathome.Writeanessayofabout120wordsmakingreferencetothefollowing
随机试题
体积为8.20×10-3m3,压强为1.01325×105Pa的氮气,在压强不变的条件下,从温度为300K加热至温度为400K,则所需的热量为()。
某单位的财务人员买了甲、乙、丙三本工具书,这三本书的封面不一样,有红色、有黄色、有蓝色。其中,丙书的价格比黄色封面的书的价格要高,甲书和蓝色封面的书的价格不一样,蓝色封面的书的价格比丙书的价格要低。据此,可以推出甲、乙、丙三本书的封面颜色分别为(
决定个体的外显行为和内隐行为并使其与他人的行为有稳定区别的综合心理特征称之为自我。()
移动通信一般使用甚高频(VHF)传输。()
公安机关在紧急处置重大灾害事故或者平息叛乱时,在不得已的情况下所采取的非常措施是()。
根据所给文字资料回答以下问题。2008年1~5月份,我国规模以上工业企业(年主营业务收入500万以上的企业,下同)实现利润10944亿元,同比增长20.9%。在规模以上工业企业中,国有及国有控股企业实现利润424.6亿元,同比增长1.5%;集体企业实
根据下列材料回答问题。从2014年起,我省在粤东西北地区以县(市、区)为单位遴选首批14个省级新农村连片示范建设工程,三年将建成42个省级新农村示范片(不含珠三角地区)。根据工作进度安排,示范片建设一年初见成效,两年基本实现目标。与此同时,珠三角
某书店老板去图书批发市场购买某种图书,第一次进书用100元,按该书定价2.8元出售,很快售完。第二次进书时,每本的进价比第一次增加0.5元,用去150元,所购数量比第一次多10本。这批书按定价售出时出现滞销,便以定价的5折售完剩余图书。那么他第二次售书可能
下面心理学技术或原理是以强化理论为基础的是
Thestudentwrotea______report.
最新回复
(
0
)