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Passage One
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. (9) We can now predict earthquake 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 you to three prediction models that have been developed.
(l0) The first prediction model looks along earthquake faults, those cracks in the Earth's crust, to find what are known as seismic gaps. Seismic gaps are places where the fault has shown little or no seismic activity for a long time. This theory postulates that such places are due for a major shock.
The second model relies on phenomena—like ground tilt. (11) Using long cylindrical tubes containing water, observers noted that ground tilt 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 evacuated 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 minor ones. Starting with the measurements and timing 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 time and places, but that may change as it is further developed.
(12) For the moment, none of these models can predict with reasonable levels of confidence.
9. What can we know about the earthquake prediction according to the speaker?
10. What is the earthquake fault?
11. Why could the scientists correctly predict Haicheng quake of 1975?
12. What is the speaker's attitude toward the three prediction models?
文章一
到目前為止，大家看到過很多介紹地震給人們的生命及財產帶來的慘重損失的文章。這也是地震學家一直致力于大力研發地震預報方法的原因。我們現在已經可以準確地預測到地震，但只能找到可能發生地震的危險區域，不可預測地震發生的具體時間和地點。今天我想向大家介紹三種地震預測方法。第一種方法是根據地震斷層——地殼裂縫——尋找所謂的“地震空區”。地震空區是通過地震斷層找到的長時間沒有發生地震活動的地區。這種預測方法認為地震空區將是大地震的主震區。第二種預測方法根據地表現象判斷，比如地表傾斜。研究人士通過使用裝有水的圓形試管觀測到，地表傾斜往往是大地震的前兆。這種方法成功預測了1975年的海城地震。這也是科學家第一次成功地預測到地震。地震發生前，一百萬人從這座中國城市中撤離。但不幸的是，這種方法的有效性并不具有一貫性，因此我們不能說這是一種完美的方法。第三種方法基于一個理論，這個理論就是大地震總是緊密跟隨在一些小震之后。這種方法用預測小地震的震級和發生時間確定的復雜公式來測算大地震發生的最可能的發生時間。現在這種方法和第一種方法一樣，無法預測地震的具體時間和地點。但是隨著進一步的研究情況可能會發生改變。就目前而言，沒有哪種模型可以很有信心地，合理地做出地震預測。
9.根據演講內容，關于地震預測我們可以了解到什么？
10.地震斷層是什么？
11.1975年科學家們為何準確地預測到了地震？
12.演講者對三種地震預測方法的態度是什么？
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