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Listen to part of a lecture in an Earth Science class. The class has been discussing volcanoes.
请听地球科学课上的部分内容。这节课讨论的是火山。
Okay. We know the Earth’s surface, the crust, is made up of tectonic plates,
我们知道地球的表面也就是地壳是由地壳板块构成的，
and that these huge slabs of rocky crust are slowly sliding over or under or past each other.
这些巨大的岩壳慢慢地滑到彼此上方或下方，或滑过对方。
And we said that most of the world’s volcanoes occur at the boundaries of these tectonic plates
我们说世界上大部分的火山都是在这些地壳板块的交界处喷发的，
where you have hot molten rocks squeezing up through gaps between the plates.
在这些地方熔化了的炙热岩石通过这些板块之间的裂缝不断挤压上涌。
But some volcanoes occur not at the edges, but in the middle of a continental or oceanic plate.
但是有一些火山不在边缘处喷发，而是在一个大洲或海洋板块的中央喷发。
The Hawaiian islands, for example, are thousands of kilometers away from any plate boundary, and yet
举个例子来说，夏威夷群岛距离任一板块界线都有数千公里远，但
you have vast amounts of magma, molten rock or lava, flowing up through the earth’s crust, which means, of course,
却有巨大数量的岩浆穿过地壳喷涌而出，这无疑意味着
that volcanic activity there can’t be explained simply by plate tectonics.
那里的火山活动不能简单地用板块构造论来解释。
So, how do we explain these volcanic anomalies, these exceptions to the general rule?
那么，我们该如何解释这些异常的火山，这些一般规则的例外呢？
Well, back in 1963, a geophysicist by the name of Wilson came up with a hot spot theory
在1963年，一位叫做Wilson的地球物理学家提出了一个热点理论
to explain how this particular type of volcanic activity can occur and can go on for maybe tens or even hundreds of millions of years.
来解释这种类型的火山活动是如何发生并持续数千万年甚至数亿年的。
