首页
登录
职称英语
The ocean bottom—a region nearly 2.5 times greater than the total land area
The ocean bottom—a region nearly 2.5 times greater than the total land area
游客
2023-12-27
18
管理
问题
The ocean bottom—a region nearly 2.5 times greater than the total land area of the Earth —is a vast frontier that even today is largely unexplored and uncharted. Until about a century ago, the deep-ocean floor was completely inaccessible, hidden beneath waters averaging over 3,600 meters deep. Totally without light and subjected to intense pressures hundreds of times greater than at the Earth’s surface, the deep-ocean bottom is a hostile environment to humans, in some ways as forbidding and remote as the void of outer space.
Although researchers have taken samples of deep-ocean rocks and sediments for over a century, the first detailed global investigation of the ocean bottom did not actually start until 1968, with the beginning of the National Science Foundation’s Deep Sea Drilling Project (DSDP). Using techniques first developed for the offshore oil and gas industry, the DSDP’s drill ship, the Glomar Challenger, was able to maintain a steady position on the ocean’s surface and drill in very deep waters, extracting samples of sediments and rock from the ocean floor.
The Glomar Challenger completed 96 voyages in a 15-year research program that ended in November 1983. During this time, the vessel logged 600,000 kilometers and took almost 20,000 core samples of seabed sediments and rocks at 624 drilling sites around the world. The Glomar Challenger’s core samples have allowed geologists to reconstruct what the planet looked like hundreds of millions of years ago and to calculate what it will probably look like millions of years in the future. Today, largely on the strength of evidence gathered during the Glomar Challenger’s voyages, nearly all earth scientists agree on the theories of plate tectonics and continental drift that explain many of the geological processes that shape the Earth.
The cores of sediment drilled by the Glomar Challenger have also yielded information critical to understanding the world’s past climates. Deep-ocean sediments provide a climatic record stretching back hundreds of millions of years, because they are largely isolated from the mechanical erosion and the intense chemical and biological activity that rapidly destroy much land-based evidence of past climates. This record has already provided insights into the patterns and causes of past climatic change—information that may be used to predict future climates. [br] Deep-ocean sediments provide better information about the world’s past climate because they______.
选项
A、are well protected
B、have land-based evidence
C、are in isolation
D、have a longer history
答案
A
解析
细节题型。 答案出自第四段第二句Deep-ocean sediments provide a climatic record stretching back hundreds of millions of years…
转载请注明原文地址:https://tihaiku.com/zcyy/3310745.html
相关试题推荐
Insuranceisthesharingof【C1】________Nearlyeveryoneisexposed【C2】_______
Insuranceisthesharingof【C1】________Nearlyeveryoneisexposed【C2】_______
Insuranceisthesharingof【C1】________Nearlyeveryoneisexposed【C2】_______
Insuranceisthesharingof【C1】________Nearlyeveryoneisexposed【C2】_______
Insuranceisthesharingof【C1】________Nearlyeveryoneisexposed【C2】_______
Insuranceisthesharingof【C1】________Nearlyeveryoneisexposed【C2】_______
Howmanyregionsareinvolvedintheinternationalstudy?[br][originaltext]
Howmanyregionsareinvolvedintheinternationalstudy?[br][originaltext]
Howmanyregionsareinvolvedintheinternationalstudy?[br][originaltext]
Whatkindofscenemightbeshowninatypicalregionalistpainting?A、Peoplewor
随机试题
Thethirdcategoryrelatestoprivate______,whereanequalityofbargainingpow
社会主义核心价值观中社会层面的价值取向是自由、平等、公正、法治。()
安全色是表达安全信息含义的颜色,能使人迅速发现或分辨安全标志和提醒注意,以防发生
阐述规则的时候,新教师往往是简单明了的。()
水准面有( )个。A、1 B、10 C、有限 D、无数
胰腺疾病和胆道疾病互相关联的解剖基础是由于A.胰管与胆总管两者解剖位置靠近 B
血小板增多,可见于A、再生障碍性贫血 B、急性白血病 C、脾功能亢进 D、
根据所提供的教材片段,设计l课时的教学简案。 要求: (1)写出一篇规范完整
下丘脑神经细胞产生的调节肽的作用是通过A.下丘脑-垂体束运送到腺垂体B.下丘脑-
关于幼儿园的班级规模,以下说法正确的是( )。A.小班(三至四周岁)二十五人
最新回复
(
0
)