All nations agree that cooperative efforts are needed to share in research to study and predict earthquakes. In July 1956 the fi

admin2015-02-12  20

问题     All nations agree that cooperative efforts are needed to share in research to study and predict earthquakes. In July 1956 the first World Conference on Earthquake Engineering was held in Tokyo. Although we are a long way from consensus on how far we should go in terms of addressing scientific questions with potential application to earthquake prediction, many point out that low-probability short-term forecasts, while not justifying mass evacuation of cities, may help maintain a state of preparedness beneficial in earthquake-prone areas.
    Time-dependent hazard maps already in use in California have led to significant practical benefits in terms of increased investment in aseismatic building construction. However, there is also a potential downside to identifying some areas as being at high risk, in the sense that this may lead to unwarranted complacency in areas identified as being at low risk.
    We remain a long way from proving that any earthquake prediction scheme can succeed better than predictions based on the statistics of earthquakes, but this debate has highlighted in the clearest terms possible that when scientists speak of "earthquake prediction", they do not imply the type of accurate short-term prediction that might allow public evacuations before an individual event. Instead the predictions implied come under the general category of probabilistic forecasts for a population of earthquakes.
    At depths of several miles inside the earth, the weight of rocks causes great pressure which sometimes causes rocks to break and slip, forming faults(great cracks).When slippage occurs, shock waves are felt and can be detected with seismographs thousands of miles away, but it is important to note that in the end, it is the collapse of man-made structures that causes most of the death and damage. While we continue to explore the degree of predictability of earthquakes on rigorous observational, statistical and theoretical grounds, we should therefore not lose sight of the fact that the best way of preparing for the inevitable remains in the development of land use plans, and building and infrastructure design codes to mitigate their worst effects.
The seismograph is most useful in______.

选项 A、controlling faults
B、pinpointing the location of shock waves
C、preventing destruction
D、warning of forthcoming earth tremors

答案B

解析 属事实细节题。第四段直接提到:“用地震仪在几千米外就能感知和探测到冲击波”。
转载请注明原文地址:https://kaotiyun.com/show/vE74777K
0

最新回复(0)