首页
登录
职称英语
[originaltext]Moderator: Good morning, class. Today Professor Liu will give us
[originaltext]Moderator: Good morning, class. Today Professor Liu will give us
游客
2023-08-12
48
管理
问题
Moderator: Good morning, class. Today Professor Liu will give us a lecture about earthquakes. Welcome.
Professor Liu: Thank you. As you know, some earthquakes are not powerful enough to be felt on the earth’s surface while in others, people can, indeed, feel the earth shaking. And of course, there might be violent movement, often with catastrophic results. What we feel during an earthquake or huge explosion are a series of waves called seismic waves.
In an earthquake, you might initially feel some minor trembling, then perhaps violent shaking, and then some more tremors. [16] The reason why you feel these different types of movement is because there are different kinds of seismic waves. There are two major types of seismic waves: body waves and surface waves.
The waves that you feel first are body waves. These mainly travel deep through the earth’s interior rather than at the surface. Some of them travel very fast, and that’s why you feel them first. [17] But because they travel deep inside the earth, they’re felt only as tremors. There are two types of body waves. The first type of body wave is the P wave or primary wave. It’s the fastest kind of seismic wave. These waves can move through any type of material, including rock and fluids. Because of this and because of their speed, these waves are the first to reach the earth’s surface. You likely won’t even hear or feel these waves, but animals may hear them. They’re not strong enough to cause significant damage. The other type of body wave is the S wave or secondary wave. Because S waves travel at half the speed of P waves, you won’t feel them in the beginning.
[18-1] Unlike body waves, surface waves move at or near the earth’s surface. These waves are similar to ripples on water. [18-2] They are usually the most destructive type of seismic wave because of their lower frequency, larger amplitude, and longer duration. There are two types of surface waves. The first kind of surface wave is called a love wave. It’s the fastest surface wave. The other kind of surface wave is the Rayleigh wave. It rolls along the ground just like a wave rolls across a lake or an ocean. As a result, it moves the ground up and down and side to side in the same direction that the wave is moving. [19] Most of the shaking felt from an earthquake is due to the Rayleigh wave, which can be much larger than the other waves. They are slower than body waves, and sometimes cars might appear to be moving up and down with these waves.
Questions 16 to 19 are based on the recording you have just heard.
16.Why do we feel different types of movement in an earthquake?
17.Why do we feel body waves only as tremors?
18.What are the most destructive type of seismic wave?
19.Which seismic wave brings us shaking felt from an earthquake?
选项
A、The love wave.
B、The primary wave.
C、The surface wave.
D、The Rayleigh wave.
答案
D
解析
转载请注明原文地址:https://tihaiku.com/zcyy/2920239.html
相关试题推荐
[originaltext]Whyshouldyouconsidertakingacourseindemographyincoll
[originaltext]Whyshouldyouconsidertakingacourseindemographyincoll
[originaltext][19]SwedenwasthefirstEuropeancountrytoprintandusep
[originaltext][19]SwedenwasthefirstEuropeancountrytoprintandusep
[originaltext][19]SwedenwasthefirstEuropeancountrytoprintandusep
[originaltext][19]SwedenwasthefirstEuropeancountrytoprintandusep
[originaltext][16]Well,mycurrentresearchisreallyaboutconsumerbehav
[originaltext][13]MostAmericansdon’teatenoughfruits,vegetablesorwh
[originaltext][9]Whenfacinganewsituation,somepeopletendtorehearse
[originaltext]W:Mr.DeKeyzer,I’magreatloverofyourbookMomentsBeforet
随机试题
Designingalenscanbecomparedtoplayingchess.Inchessaplayertriest
Arelationshipwithyourcustomerislikeanyrelationship:It【C1】______time
However,theformerFedchairmanplayeddownthepracticalimplicationsoftheA
ExerciseIsGoodforYourBodyandYour
除哪一项外,是婴幼儿期便血的常见原因A.肠重复畸形 B.肠扭转 C.梅克尔憩
健康教育的核心问题是改变个体和群体的A.知识 B.态度 C.价值观 D.信
下列各项检查不能反映肾小球滤过功能的是A:内生肌酐清除率B:血肌酐测定C:血
根据收入形式分类,财政收入可以分为()。A.税收收入和非税收入 B.中央财政收
A.种植转移 B.淋巴转移 C.血行转移 D.直接浸润 E.跳跃转移给胃
第三方认证机构对施工企业质量管理体系实施的监督管理应每()进行一次。A.一年
最新回复
(
0
)