Plate Tectonics托福听力红Delta原文翻译及问题答案
2023-05-21 12:27:09 来源:金宝搏188入口
Plate Tectonics托福听力红Delta原文翻译及问题答案, 今天金宝搏188入口 就来为大家分析这个问题。
一、Plate Tectonics 托福听力原文:
We currently believe that the earth’s crust—the rocky part of the earth—is composed of several large, rigid plates. These plates are being created at some edges and being destroyed at others. They’re also moving across the earth. This theory is called plate tectonics. It was first put forth in 1963 by a Canadian geophysicist by the name of Tuzo Wilson.
Tuzo Wilson was instrumental in advancing the theory of plate tectonics. He suggested that the Hawaiian and other volcanic island chains might have formed as a result of the movement of a plate over a motionless “hotspot” in the earth’s mantle. Hundreds of studies have proved that Wilson was right. However, in the early 1960s, his idea was considered so radical that his “hotspot” manuscript was initially rejected by all the major international scientific journals.
Basically, plates are areas of the earth’s crust that move as a unit. At the present time, there are eight large plates, as well as a similar number of smaller plates.
According to the theory of plate tectonics, a plate has three kinds of boundaries with other plates: oceanic ridges, oceanic trenches, and transform faults. Most of the world’s earthquakes and volcanoes occur at plate boundaries. This is what you’d expect because plate boundaries are where a great deal of friction and stress occur.
At plate boundaries, a couple of things can happen. One is that rock is forced up from the mantle in molten form as lava—at ridges. Another is that rock is melted and forced back into the mantle—at trenches. This process of rock being “swallowed” or forced back into the earth’s mantle is called subduction. During subduction, as a plate dives into the depths, we think part of it finds its way back to the surface in the form of volcanoes.
The theory of plate tectonics and the discovery of sea floor spreading have confirmed the theory of continental drift, the movement of continents. Sea floor spreading was discovered in the North Atlantic, and soon afterward in all other oceans.What we found is that—in the areas around oceanic ridges— the deep sea floor is formed by rising lava, which then spreads out sideways in both directions.
So, does the spreading of the ocean floor mean that the surface of the earth is increasing? No, not in the least. Sea floor spreading doesn’t cause an increase in the earth’s surface. And why not? Because the lava that rises and spreads from the oceanic ridges sinks again elsewhere in subduction zones, which are nearly identical with the ocean trenches.
Subduction zones are areas of frequent earthquakes and are usually associated with the rows of volcanic islands that accompany the oceanic trenches. Subduction is currently happening beneath island arcs, like Japan. Subduction is also taking place on the Pacific Northwest Coast of North America, beyond the end of the San Andreas Fault. This is where a subducted plate is thought to have disappeared beneath the North American plate in recent geological time, leaving the volcanoes of the Cascade Range as evidence of its past existence.
二、Plate Tectonics 托福听力中文翻译:
我们目前认为,地壳——地球的岩石部分——是由几个大而坚硬的板块组成的。这些板块在一些边缘形成,在其他边缘被破坏。它们也在地球上移动。这个理论被称为板块构造。1963年,一位名叫图佐·威尔逊的加拿大地球物理学家首次提出了这一观点。
图佐·威尔逊在推进板块构造理论方面发挥了重要作用。他认为夏威夷和其他火山岛链可能是板块在地幔中静止的“热点”上方运动的结果。数百项研究证明威尔逊是对的。然而,在20世纪60年代初,他的想法被认为是如此激进,以至于他的“热点”手稿最初被所有主要国际科学期刊拒绝。
基本上,板块是作为一个整体运动的地壳区域。目前,有八个大板块,以及同样数量的小板块。
根据板块构造理论,板块与其他板块有三种边界:洋脊、海沟和转换断层。世界上大多数地震和火山都发生在板块边界。这就是你所期望的,因为板块边界是产生大量摩擦和应力的地方。
在板块边界,可能会发生一些事情。一种是岩石以熔融的形式从地幔中被挤出,形成山脊处的熔岩。另一个原因是,岩石被融化,并被迫回到地沟处的地幔中。这种岩石被“吞没”或被迫返回地幔的过程称为俯冲。在俯冲过程中,当板块潜入深处时,我们认为它的一部分会以火山的形式返回地表。
板块构造理论和海底扩张的发现证实了大陆漂移理论,即大陆运动理论。在北大西洋发现了海底扩张,不久之后在所有其他海洋都发现了海底扩张。我们发现,在海脊周围的区域,深海海底是由上升的熔岩形成的,熔岩随后向两个方向横向扩散。
那么,海底的扩张是否意味着地球表面正在增加?不,一点也不。海底扩张不会导致地球表面的增加。为什么不呢?因为从洋脊上升和扩散的熔岩在俯冲带的其他地方再次下沉,这与海沟几乎相同。
俯冲带是地震频发的地区,通常与伴随海沟的一排排火山岛有关。俯冲目前正在岛弧下方发生,如日本。北美洲太平洋西北海岸的圣安德烈亚斯断层末端以外也发生了俯冲。这是一个俯冲板块被认为在最近的地质时期消失在北美板块之下的地方,留下喀斯喀特山脉的火山作为其过去存在的证据。
三、Plate Tectonics 托福听力问题:
Q1:
Why does the professor talk about Tuzo Wilson?
A.Wilson developed a warning system for earthquakes.
B.Wilson wrote an article that contradicted scientific law.
C.Wilson first proposed the theory of plate tectonics.
D.Wilson discovered sea floor spreading in the North Atlantic.
Q2:
Why do earthquakes and volcanoes occur at plate boundaries?
A.Plate boundaries undergo much tension and friction.
B.Temperatures fluctuate greatly at plate boundaries.
C.Earthquakes and volcanoes cause new plates to form.
D.The causes of earthquakes and volcanoes are unknown.
Q3:
What is subduction?
A.The eruption of rock from the earth in molten form
B.The formation of the deep sea floor by rising lava
C.The process of rock being forced into the earth’s mantle
D.The continuous drift of continents toward the northwest
Q4:
Identify the area in the diagram where subduction occurs.
A.A
B.B
C.C
D.D
Q5:
Why does the professor ask this:
A.To test the students’understanding of plate tectonics
B.To describe an event that confuses many scientists
C.To point out a theory that has never been confirmed
D.To introduce a phenomenon that he intends to explain
Q6:
Which of the following are associated with subduction zones?
Click on two answers.
A.The pollution of the sea floor
B.Chains of volcanic islands
C.The sliding of one plate under another
D.Frequent thunderstorms and tornadoes
四、Plate Tectonics 托福听力答案:
A1:正确答案:C
A2:正确答案:A
A3:正确答案:C
A4:正确答案:D
A5:正确答案:D
A6:正确答案BC
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