10 Earthquakes and Tsunamis

Earthquakes and Tsunamis

地震和海啸

Shaking earth. During an earthquake, the ground suddenly trembles. Earthquakes can happen on land or under the sea. Some earthquakes shake the ground violently. An earthquake has made the big cracks in these roads in Haiti.

地球抖动。地震时，地面突然震动。 地震可能发生在陆地上，也可能发生在海底。 有些地震使地面剧烈震动。 一场地震在海地的道路上造成了巨大的裂缝。

Moving rock. The Earth is made of rock. Inside the Earth, there is very hot rock that moves around very, very slowly. The Earth's surface is made up of big pieces of hard rock, called plates. The plates move around on top of the hot rock. As they move, some plates push against each other. Others pull apart.

岩石移动。地球由岩石构成。 在地球内部，有非常热的岩石，移动得非常非常慢。 地球表面是由大块坚硬的岩石组成的，这些岩石被称为板块。 板块在热岩石上移动。 当它们移动时，一些板块相互推动。 另一些则四分五裂。

When plates push against each other for millions of years, they form mountains. Here are the edges of two plates in Iceland. The plates are moving away from each other, in opposite directions. The gap made in the Earth's surface is called a rift.

当板块相互挤压数百万年，它们就形成了山脉。 这是冰岛两个板块的边缘。 两个板块正朝着相反的方向相互远离。 地球表面形成的裂缝被称为裂谷。

Faults. Most earthquakes happen where two plates scrape against each other. In some places there are cracks near the edges of the plates, called faults. This is the San Andreas fault in California, U.S.A. Over 10,000 earthquakes happen along its length, every year.

的缺点。大多数地震发生在两个板块相互摩擦的地方。 在一些地方，靠近板块边缘的地方有裂缝，称为断层。 这是美国加州的圣安德烈亚斯断层 每年沿着它的长度发生一万多次地震。

Sections of rock in a fault shift and push against each other. Sometimes, a big section of rock suddenly slips, making the surrounding rock shake. The shaking spreads up to the surface, causing an earthquake. As the rock in a fault settles after a big earthquake it can cause smaller quakes, called aftershocks.

断层中的岩石分段移动并相互挤压。 有时，一大块岩石突然滑动，使周围的岩石震动。 震动向上传播到地表，引起地震。 当断层中的岩石在大地震后沉降时，它可以引起较小的地震，称为余震。