首页
登录
职称英语
This view may be correct: it has the advantage that the currents are driven
This view may be correct: it has the advantage that the currents are driven
游客
2023-12-23
74
管理
问题
This view may be correct: it has the advantage that the currents are driven by temperature differences that themselves depend on the position of the continents. Such a back-coupling, in which the position of the moving plate has an impact on the forces that move it, could produce complicated and varying motions.
On the other hand, the theory is implausible because convection does not normally occur along lines, and it certainly does not occur along lines broken by frequent offsets or changes in direction, as the ridge is. Also it is difficult to see how the theory applies to the plate between the Mid-Atlantic Ridge and the ridge in the Indian Ocean. This plate is growing on both sides, and since there is no intermediate trench, the two ridges must be moving apart. It would be odd if the rising convection currents kept exact pace with them. An alternative theory is that the sinking part of the plate, which is denser than the hotter surrounding mantle, pulls the rest of the plate after it. Again it is difficult to see how this applies to the ridge in the South Atlantic, where neither the African nor the American plate has a sinking part.
Another possibility is that the sinking plate cools the neighboring mantle and produces convection currents that move the plates. This last theory is attractive because it gives some hope of explaining the enclosed seas, such as the Sea of Japan. These seas have a typical oceanic floor, except that the floor is overlaid by several kilometers of sediment. Their floors have probably been sinking for long periods.
It seems possible that a sinking current of cooled mantle material on the upper side of the plate might be the cause of such deep basins. The enclosed seas are an important feature of the earth’s surface and seriously require explanation because, in addition to the enclosed seas that are developing at present behind island arcs, there are a number of older ones of possibly similar origin, such as the Gulf of Mexico, the Black Sea, and perhaps the North Sea. [br] According to the traditional view of the origin of the ocean basins, which of the following is sufficient to move the continental plates? ______
选项
A、Increases in sedimentation on ocean floors.
B、Movement of mid-ocean ridges.
C、Sinking of ocean basins.
D、Differences in temperature under oceans and continents.
答案
D
解析
转载请注明原文地址:https://tihaiku.com/zcyy/3298213.html
相关试题推荐
Manyfarmershavetakenadvantageofrainwhenitisgoingtocome,bymakingha
Whichofthefollowingstatementsiscorrect?[br][originaltext]China’
Whichofthefollowingstatementsiscorrect?[originaltext]China’sfurt
WhichofthefollowingstatementsisNOTcorrect?[br][originaltext]As
WhichofthefollowingstatementsisNOTcorrect?[br][originaltext]As
WhichofthefollowingstatementsisNOTcorrect?[br][originaltext]As
WhichofthefollowingstatementsisNOTcorrect?[br][originaltext]As
WhichofthefollowingstatementsisNOTcorrect?[originaltext]AsAsia-P
WhichofthefollowingstatementsiscorrectabouttheBeltandRoad?[br][ori
WhichofthefollowingstatementsiscorrectabouttheBeltandRoad?[br][ori
随机试题
Whatisthepassagemainlyconcerned?[br]AccordingtothePassage,whatcontri
某新建汽车加油站竣工之后,申请相关部门进行消防设施竣工验收,施工单位需要提交的资
确定施工流向时,工程各部位的繁简程度,哪些部位应先施工()。A.技术简单 B
A.乌贼骨B.罂粟壳C.肉豆蔻D.赤石脂E.浮小麦虚寒气滞、久泻不止者,治疗宜选
安全工器具的保管及存放应满足()及产品说明书要求。企业标准$;$公司标准$;$公
旅游产业结构优化的标志包括( )。A.旅游资源配置的有效性 B.旅游区域分布
(此知识点已变动)下列薪酬形式中,属于间接薪酬的有()A.奖金 B.员
根据波特的五种竞争力分析理论,下列各项关于供应商讨价还价能力的说法中,错误的是(
某建筑工程公司与建设单位签订一份大型资产建造合同,合同规定,以双方约定的基本成本
肝硬化时,肝脏解毒功能下降表现为A.男性乳腺发育 B.食管静脉曲张 C.氨中
最新回复
(
0
)