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People in Mutsuhito, Japan, lived through one hundreds, and sometimes thousands, a day．But they couldn’t get used to it．
What was it? It was a string of earthquakes that made the small town shake all the time．This went on for more than a year．Sometimes the quakes were very small．Only certain instruments could pick them up．At other times, the quakes damaged houses and land．The people were always afraid．They wished they knew how to stop the ground from shaking．
People all over the world would like to know when an earthquake is coming．But an earthquake is almost always a surprise．Under the surface of the Earth, huge blocks of rock drift apart or slide against each other．The ground above splits apart or rumbles and shakes．
Some scientists hope to predict quakes by keeping a close watch on animals．It seems that some animals can sense an earthquake coming．In 1969, animals in a Chinese zoo began to act funny one day．Swans flew out of their pond．A panda sat down, covered its eyes with its paws, and groaned．The animals seemed to know that something was about to happen．And it did．An earthquake struck．What was it that the animals sensed? Scientists are trying to find out．
Keeping close track of the Earth’s magnetic force in earthquake areas may also help．A few years ago, in Hollister, CA, scientists kept a record of the area’s magnetic pull．For one week, the force grew stronger．Then it weakened suddenly．A day later, an earthquake struck．
It may become possible to know when and where an earthquake will happen．But it will be much harder to stop one from happening．
Many scientists think that the Earth’s covering is not smooth．They say the earth’s “skin” is made up of huge puzzle pieces called plates．Land and ocean floors make up these huge plates．Under the Earth’s crust(外壳), or plates, is hot rock．The plates float on top of this rock．Sometimes the rock forces its way through the crust．What happens then? A volcano is born! More often, the rock moves and forces the plates to pull away from each other, causing earthquakes to happen．(Volcanoes and earthquakes often go together．)
Sometimes, the plates end up on top of each other．When this happens, the land above may look strange．Seen from the air, there seems to be a long scar in the Earth．This is called a fault(断层)．The areas along faults have more earthquakes than other parts of the Earth．
For now, we’ll just have to shake along with the Earth．It goes through millions of small earthquakes every year．With luck, you won’t feel a thing!
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