大学英语自学教程 下册 un06

[07:50.36]测为4.5级的地震能带来轻微破坏,
[07:53.39]and an earthquake that has a reading of over 7 can cause major damage
[07:56.32]读数超过7级的地震会带来较大破坏.
[07:59.24]It is important to note that a reading of 4
[08:01.27]一定要注意到读数为4级的地震
[08:03.29]indicates an earthquake ten times as strong as one with a reading of 3.
[08:06.41]表明其强度为读数3级的地震的10倍.
[08:09.53]Scientists want to be able to predict those earthquakes
[08:14.26]that have a reading of over 4 on the Richter Scale.
[08:16.69]科学家们想预报那些读数超过里氏4级的地震.
[08:19.12]How do earthquakes occur?
[08:20.75]  地震是如何发生的呢?
[08:22.39]Earthquakes are caused by the shifting of rocks
[08:24.61]地震是由沿着地壳中的裂缝,
[08:26.83]along cracks or faults,in the earth's crust.
[08:29.47]或称断层处的岩石发生位移而引起的.
[08:32.10]The fault is produced
[08:35.27]when rocks near each other are pulled in different directions.
[08:37.84]当邻近岩石受到不同方向的拉力时便产生了断层.
[08:40.41]The best-known fault in North America is the San Andreas fault
[08:43.39]北美洲最著名的断层是
[08:46.37]in the state of California in the United States.
[08:48.74]位于美国加利福尼来州的圣安德烈亚斯断层.
[08:51.12]The nations that are actively involved in earthquake prediction
[08:53.30]积极参与地震预报研究的国家
[08:55.48]program in clude Japan,China,Russia,and the United States.
[08:59.36]包括日本,中国,俄罗斯和美国.
[09:03.24]These countries have set up seismic networks in areas of their countries
[09:07.34]where earthquakes are known to occur.
[09:09.33]这些国家在本国发生地震地地区建立了地震网络.
[09:11.31]These networks are on the alert
[09:15.08]for warning signs that show the weakening of rock layers
[09:17.56]这些网络一直处于戒备状态,搜索告警的迹象,
[09:20.04]that can precede an earthquake.
[09:21.92]这些迹象显示出在地震前可能发生的岩层松动的状况.
[09:23.80]Many kinds of seismic instruments
[09:28.06]are used by the networks to monitor the movements of the earth's crust.
[09:30.58]这些网络运用多种地震仪器来监测地壳的运动.
[09:33.10]The scientists also check water in deep wells.
[09:35.43]科学家还检查深井里的水,
[09:37.75]They watch for changes in the water level
[09:41.83]and temperature that are associated with movement along faults.
[09:44.50]他们密切注意与断层运动有关的水位和水温的变化.
[09:47.18]Scientists in China,Russia,and the United States measure radon in ground water.
[09:50.90]中国,俄国和美国的科学家们测量地下水中的氡.
[09:54.63]Radon is a gas that comes from the radioactive decay of radium in rocks.
[09:57.75]氡是来自岩石中镭辐射衰变而产生的一种气体.
[10:00.87]The gas flows through the ground and dissolves in underground streams and wells.
[10:04.15]这种气体从地面溢出并溶解到地下水和井里.
[10:07.43]Scientists speculate that the amount of radon increases in the ground
[10:10.31]科学家们推测当岩层发生位移时,地层中氡的数量就会增加;
[10:13.20]when rocks layers shift,exposing new rock,and thus more radon.
[10:16.42]新岩石露出时,就会产生更多更好的氡.
[10:19.65]Chinese and Russian scientists
[10:21.43]中国和俄国科学家
[10:23.20]have reported that in places where stress is building up,
[10:25.54]已有记录,在应力增长的地方,
[10:27.88]the radon levels of the water build up too.
[10:30.01]水里氡的含量也就增长.
[10:32.14]When the radon levels of the water subside
[10:34.21]当水中氡的含量下降,
[10:36.29]and drop back to normal reading san earthquake may occur.
[10:38.86]回到正常读数时,地震就可能发生.
[10:41.44]United States scientists
[10:44.81]have also placed radon monitoring stations in earthquake zones,
[10:50.27]particularly California.
[10:52.04]美国科学家也在地震区,特别是加利福尼亚,设置了氡监测站.
[10:53.82]However,all the scientists agree that more data is necessary
[10:56.69]不过,所有科学家都一致认为,
[10:59.57]to prove that radon' levels in water
[11:03.41]are associated with the possible birth of an earthquake.
[11:05.89]需要有更多的资料才能证明水中氡的含量和可能发生的地震有关.
[11:08.37]Earthquake prediction is still a young science.
[11:10.43]地震预报还是一门年轻的科学.
[11:12.50]Everyone agrees that earthquakes Cannot be predicted with any reliability.