China's Seismic Zones

中国的地震带

As early as 1970, the State Seismological Bureau in China had identified Liaoning Province as a high earthquake-prone area. A short term earthquake prediction was given to the population in the Haicheng area as early as mid-January 1975. This prediction was based on a number of geophysical observations of precursor events as well as abnormal animal behavior. When the earthquake struck, the people of Haicheng and neighboring towns had been warned, and the warning saved many lives and averted a disaster of major proportions. Four other disastrous earthquakes were predicted by Chinese scientists during the 1975/76 period, giving hope that earthquake prediction was finally possible.

早在上个世纪70年代，中国国家地震局就将辽宁省列入了地震危险区。1975年1月中旬，地震局监测到了地震并向海城人民发出了警告。除了对地震前兆的地 球物理现象观察，这次地震的准确预测还要多亏对动物异常活动的观察。地震来临之前，海城及周边地区的群众就已经得到地震警报，不仅拯救了无数多人的生命， 还避免了一场大灾难。1975至1976年之间，科学家们还成功预测了四场地震，这为地震预测的可能性增添了一丝希望。

When a great earthquake with magnitude of 7.8 struck the city of Tangshan on July 28, 1976, at least 655,000 people died and 780,000 more were injured. There was no prediction for this earthquake, and therefore no warning. Hope in the accurate predictability of earthquakes evaporated. Although precursor events had been observed and geophysical and geochemical anomalies had been detected, these precursor events occurred over a very widely-spread area making it extremely difficult for scientists to focus on any particular region and thus issue a short-term prediction, or a warning. There were remarkable differences between precursor events of this particular earthquake and those of other predicted earthquakes. Furthermore, no significant foreshocks were observed. The examples given illustrate the validity of earthquake prediction at the present time. However, progress is being made which may lead to better predictions.

1976年7月28日，唐山发生里氏7.8级大地震，造成至少65.5万死亡，78万人受伤。因为这场地震没有任何预报，因此也没有警告，想要准确预测地 震的希望成为泡影。尽管观察到了地震前兆现象，也监测到了物理和化学上的异常现象，但是由于这些前兆发生的地域过于广泛，使得科学家无法精确预测并发出警 告。这次大地震的前兆与以往地震的和被预测到地震的前兆有很大的不同。不仅如此，科学家们没有观测到任何前震。上述例子都说明了当前地震预测的有效性，然 而，科学家们仍在不断努力使预测工作更为准确。

Knowing that an earthquake will occur in any particular region is not sufficient. There is no doubt that earthquakes can occur anywhere along any of the numerous faults of China. To provide predictions too far into the future would be totally impractical. Thus, only the short-term predictions should be relied upon, since longer term predictions could have greater social and economic effects, particularly if they are false. For predictions to be of usefulness they would have to specify time, place, and magnitude of a forthcoming earthquake with sufficient precision and level of confidence to be practically useful. Studies of earthquake recurrence frequency. although useful from a statistical point of view, cannot be used with sufficient confidence for a prediction. For a prediction to be valid, it has to be sufficiently precise, and supported with a great deal of research and instrumentation. However, it is difficult, if not nearly impossible, to instrument all the faults and to monitor all the different parameters used for prediction.

仅仅知道地震会在什么地方发生是不够的。毫无疑问，中国领土上有太多断层，这些地方随时会发生地震，预测太过遥远的地震显得很不实际。所以，只有短期预测 可依靠，因为长期的预测会对社会和经济产生更大的影响，尤其当预测出现了错误时，这些影响将更大。要使地震预测真正发挥作用，预报必须有绝对的精确，而科 学家则必须有充分的自信指出地震的时间、地点及震级。但对于地震再次发生频率的研究，从统计学的角度看很有用，但这不能用于预测地震。为使预测有效，预测 必须足够精确，有很多研究和仪器数字的支持。然而，如果想要用仪器测出所有的问题，监测各种各样数据来预测地震，就算不是不可能，那也是极为困难的。

Therefore, until such time as earthquake prediction becomes a more exact science, it might be best not to issue any predictions. Hopefully, it is only a question of time before effective methods can and will be used for reliable predictions. Until then, and until the complex interactions of the behavior of earthquake faults is understood, it would be best not to utilize predictions for public evacuation. But this does not mean that preventive measures cannot be taken to ensure the safety of the public and the protection of property. With proper planning and public awareness, the effects of the earthquake hazard can be mitigated.

因此，在地震预测成为一门精确科学之前，不做任何预警是最好的办法。总有一天我们可以并将用有效的方法作出可靠的预测，这只不过是时间的问题罢了。到那个 时候，等我们对地震断层之间复杂的相互作用充分了解之后，最好就不要用预测来进行撤离了。但这并不意味着我们不能做防御措施来确保社会和财产的安全。只要 有适当的计划和公众意识，地震的危害就能得到降低。