And that's because there's a difference between what's happening on the surface -- which is obvious total growth -- and the tectonic forces beneath.

是因为地表上发生的事，里指的是人口增长，和深层地壳构造的变化是不同的。

Tension builds up between the pieces of the Earth's crust until the energy is released in the form of an earthquake.

地壳构造板块之间的张不断增加，直到能量以地震的形式释放出来。

Remember tectonic plates underneath the earth's crust.

记住地壳下面的构造板块。

Earth's crust is made up of giant sections called tectonic plates that fit together like a jigsaw puzzle.

地壳由称为构造板块的巨大部分组成，些部分像拼图游戏一样拼在一起。