Plate Tectonics托福聽力紅Delta原文翻譯及問題答案

2023-05-21 12:27:09 來源：中國教育在線

Plate Tectonics托福聽力紅Delta原文翻譯及問題答案，今天中國教育在線就來為大家分析這個問題。

一、Plate Tectonics 托福聽力原文：

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 托福聽力中文翻譯：

我們目前認為，地殼——地球的巖石部分——是由幾個大而堅硬的板塊組成的。這些板塊在一些邊緣形成，在其他邊緣被破壞。它們也在地球上移動。這個理論被稱為板塊構造。1963年，一位名叫圖佐·威爾遜的加拿大地球物理學家首次提出了這一觀點。

圖佐·威爾遜在推進板塊構造理論方面發(fā)揮了重要作用。他認為夏威夷和其他火山島鏈可能是板塊在地幔中靜止的“熱點”上方運動的結果。數百項研究證明威爾遜是對的。然而，在20世紀60年代初，他的想法被認為是如此激進，以至于他的“熱點”手稿最初被所有主要國際科學期刊拒絕。

基本上，板塊是作為一個整體運動的地殼區(qū)域。目前，有八個大板塊，以及同樣數量的小板塊。

根據板塊構造理論，板塊與其他板塊有三種邊界：洋脊、海溝和轉換斷層。世界上大多數地震和火山都發(fā)生在板塊邊界。這就是你所期望的，因為板塊邊界是產生大量摩擦和應力的地方。

在板塊邊界，可能會發(fā)生一些事情。一種是巖石以熔融的形式從地幔中被擠出，形成山脊處的熔巖。另一個原因是，巖石被融化，并被迫回到地溝處的地幔中。這種巖石被“吞沒”或被迫返回地幔的過程稱為俯沖。在俯沖過程中，當板塊潛入深處時，我們認為它的一部分會以火山的形式返回地表。

板塊構造理論和海底擴張的發(fā)現(xiàn)證實了大陸漂移理論，即大陸運動理論。在北大西洋發(fā)現(xiàn)了海底擴張，不久之后在所有其他海洋都發(fā)現(xiàn)了海底擴張。我們發(fā)現(xiàn)，在海脊周圍的區(qū)域，深海海底是由上升的熔巖形成的，熔巖隨后向兩個方向橫向擴散。

那么，海底的擴張是否意味著地球表面正在增加？不，一點也不。海底擴張不會導致地球表面的增加。為什么不呢？因為從洋脊上升和擴散的熔巖在俯沖帶的其他地方再次下沉，這與海溝幾乎相同。

俯沖帶是地震頻發(fā)的地區(qū)，通常與伴隨海溝的一排排火山島有關。俯沖目前正在島弧下方發(fā)生，如日本。北美洲太平洋西北海岸的圣安德烈亞斯斷層末端以外也發(fā)生了俯沖。這是一個俯沖板塊被認為在最近的地質時期消失在北美板塊之下的地方，留下喀斯喀特山脈的火山作為其過去存在的證據。

三、Plate Tectonics 托福聽力問題：

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.