【摘要】 以1997年玛尼地震为例,利用三维非线性动态有限元方法,再现了玛尼地震的破裂过程.研究结果表明:(1)玛尼地震产生的动态应力波随时间变化呈明显波动性且随距离衰减,沿断裂带衰减相对慢一些.其波动性是震源区不同相位应力波及一些反射波相互叠加造成的.震源区动应力强烈的波动性使破裂表现"愈合脉冲"特征.(2)玛尼地震与其后几年发生的中强余震关系密切.2001年3月5日在大震西南方向发生Ms6.4级地震、阿尔金断裂西段1999年与2000年的两次中强地震可能均主要是玛尼地震的产物.(3)玛尼地震对昆仑大震孕震区的动应力影响,卸载前产生的动应力变化大约为0.05 MPa,其远大于静应力的地震触发阈值,卸载后动应力剧烈波动,上下波动达0.2 MPa左右,其大约相当于0.02 MPa的静应力,这是静应力触发地震阈值的2倍,揭示玛尼地震很大程度上触发了昆仑大震的提前发生.更多还原

【Abstract】 In this study,the rupture process of the Mani earthquake in 1997 was simulated using the three-dimensional nonlinear dynamic finite method.The result shows that(1) Dynamic stress wave produced by the Mani earthquake presented obvious fluctuation with time,and attenuated with distances.It attenuated slowly along fault zone.Its fluctuation feature was engendered by the superposition of differ-phase and reflected stress waves.The strong fluctuation of dynamic stress in the earthquake source made rupture to show the characteristic of concrescence and pulse.(2) The Mani earthquake and its moderate aftershocks had many affinities.For example,the strain energy of Ms6.4 earthquake in the northwest of Mani on March 5,2001 and two moderate earthquakes(1999 and 2000) in the west of Altyn fault may result from the Mani earthquake mostly.(3) The dynamic stress of the Mani earthquake for the potential earthquake source of the Kunlun earthquake was about 0.05 MPa before unloading,which was more bigger than the earthquake triggering value of static stress.After unloading,dynamic stress fluctuated acutely,and its fluctuation was about 0.2 MPa that corresponds to 0.02 MPa static stress,and it was two times the earthquake triggering value of static stress.So we think that the Mani earthquake triggered the Kunlun earthquake to cause to occur sooner.更多还原