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(MA) Now, you've been reading articles about the tremendous damage done to life and property by earthquakes. That's why seismologists have been working so hard to develop methods of earthquake prediction. We can now predict earthquake [assertively] fairly well, but the predictions only locate potential areas of danger. They don't predict the specific time and location at which an earthquake is likely to occur. Today I want to introduce to you three prediction models that have been developed.
The first prediction model looks along earthquake fawlts, those cracks in the Earth's crust, to find what are known as seismic1 gaps. Seismic gaps are places where the fault has shown little or no seismic activity for a long time. This theory postulates2 that such places are due for a major shock.
The second model relies on phenomena3 --- like ground flit. Using long cylindrical4 tubes containing water, observers noted5 that ground tilt6 tended to occur before major earthquakes. That led them to correctly predict the big Haicheng [HI CHUNG] quake of 1975 --- the first successful earthquake prediction scientists have ever made. A million people were evacuated7 from that Chinese city before the earthquake struck. Unfortunately, this method hasn't worked consistently, so we can't say it's been perfected.
The third model is based on the theory that major earthquakes closely follow a series of minor8 ones. Starting with the measurements and timing9 of the smaller quakes, a complex formula calculates the "times of increased probability" of a much larger quake. Right now, this method, like the first method, cannot predict specific times and places, but that may change as it is further developed.
For the moment, none of these models can predict with reasonable levels of confidence.
The first prediction model looks along earthquake fawlts, those cracks in the Earth's crust, to find what are known as seismic1 gaps. Seismic gaps are places where the fault has shown little or no seismic activity for a long time. This theory postulates2 that such places are due for a major shock.
The second model relies on phenomena3 --- like ground flit. Using long cylindrical4 tubes containing water, observers noted5 that ground tilt6 tended to occur before major earthquakes. That led them to correctly predict the big Haicheng [HI CHUNG] quake of 1975 --- the first successful earthquake prediction scientists have ever made. A million people were evacuated7 from that Chinese city before the earthquake struck. Unfortunately, this method hasn't worked consistently, so we can't say it's been perfected.
The third model is based on the theory that major earthquakes closely follow a series of minor8 ones. Starting with the measurements and timing9 of the smaller quakes, a complex formula calculates the "times of increased probability" of a much larger quake. Right now, this method, like the first method, cannot predict specific times and places, but that may change as it is further developed.
For the moment, none of these models can predict with reasonable levels of confidence.
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1 seismic | |
a.地震的,地震强度的 | |
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2 postulates | |
v.假定,假设( postulate的第三人称单数 ) | |
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3 phenomena | |
n.现象 | |
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4 cylindrical | |
adj.圆筒形的 | |
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5 noted | |
adj.著名的,知名的 | |
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6 tilt | |
v.(使)倾侧;(使)倾斜;n.倾侧;倾斜 | |
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7 evacuated | |
撤退者的 | |
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8 minor | |
adj.较小(少)的,较次要的;n.辅修学科;vi.辅修 | |
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9 timing | |
n.时间安排,时间选择 | |
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