At
5:13 on the morning of April 18th, 1906, the city of San
Francisco was shaken by a terrible earthquake. A great part of
the city was destroyed and a large number of buildings burnt
down. The number of people who lost their homes reached as many
as 250,000. About 700 people died in the earthquake and the
fires.
Another earthquake shook San Francisco on October 17th, 1989. as
America's second strongest earthquake and about 100 people were
killed. It happened in the evening as people were travelling
home. A wide and busy road which was built like a bridge over
another road fell onto the below. Many people were killed in
their cars, but a few lucky ones were not hurt.
Luckily the 1989 earthquake did not happen in the centre of town
but about 55 kilometres away. In one part of the town a great
many buildings were destroyed. These buildings were over 60
years old, so they were not strong enough. There were a lot of
fires all over the city. The electricity was cut off for several
days too.
Why do earthquakes happen? Scientists explain that the outside
of the earth is made of a number of different plates. At San
Francisco the Pacific plate, which is moving towards the
northwest, meets the North American plate. The Pacific plate is
moving very slowly – at 5.3 centimeters(厘米)a
year. Sometimes these two plates stop and do not move for years.
Then suddenly, they jump and an earthquake is felt. As a result
of the movement of these plates, west America, near the sea, has
always been a bad place four earthquakes. When the 1906
earthquake happened, the Pacific plate jumped 5-6 meters to the
north.
Scientists are afraid that one day an even bigger earthquake
will hit the area around San Francisco. They call it "The Big
One. However, people today are still building more houses.
The population in and around San Francisco is now ten times
larger than it was in 1906. This means that if there is another
big earthquake, a great many houses and buildings will be
destroyed.
(Senior English for China Student's Book
1A
Unit 4 Workbook Reading)
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