地震是地壳在地应力的挤压、旋扭下,某些脆弱的部位发生破裂,把所积累的能量急剧释放出来,并以弹性波的形式向四周传播,引起地面产生震动的现象。地震具有突发性,又多数在夜间出现,7级以上的大地震,会给人类社会带来严重的灾难。 由于地震机制十分复杂,地震的发生规律尚未彼人类所掌握,所 Earthquake crust in the earth under the stress squeeze, twist twist, the fragile parts of the rupture, the rapid release of energy accumulated, and in the form of elastic waves spread around, causing the ground to produce vibration phenomenon. The earthquakes are sudden and mostly occur at night. The earthquakes above the magnitude of 7 have serious disastrous consequences for human society. Due to the complicated seismic mechanism, the occurrence of earthquakes has not yet been mastered by human beings