摘要
对印尼地区3574次M≥5.0地震震源断层面上的海潮负荷应力进行计算,研究了地震断层上的负荷应力随深度变化以及随断层倾角和走向的变化特征.结果表明,地震断层上的负荷正应力大于负荷切应力.逆断层上的负荷应力最大,其它依次为斜滑断层、正断层和走滑断层.倾角范围在0°—50°的断层上的负荷正应力随倾角增大有减小趋势,负荷切应力在30°—50°倾角范围的断层上较大.负荷应力随断层走向的趋势性变化不明显.不同类型断层上的负荷正应力和切应力在震源深度15km处均达到最大,之后随深度增加而减小.当震源深度小于40km时,断层面上的海潮负荷应力的量级与固体潮应力相当.因此指出,在潮汐应力对地震影响的研究中,对震源深度小于40km的海洋和沿海地震,除固体潮汐应力外还需要考虑海潮负荷应力的影响.
Ocean loading tidal stresses on the fault of 3574 earthquakes with M≥5.0 in Indonesia region are calculated.The variation of ocean loading tidal stresses with depth,fault dip and fault strike are investigated.The result shows that the loading normal stresses are larger than loading shear stresses on earthquake faults.The ocean loading tidal stress on thrust fault is the largest,and the others are orderly on oblique,normal,and strike slip faults.Loading normal stresses on faults with dip of 0°—50° have decreasing tendency with increase of dip,while loading shear stresses on faults with dip of 30°—50° are relatively large.There is no obvious tendency of change of loading stresses with fault strike.Ocean loading tidal stresses,both normal and shear,on different seismic faults all reach the largest values at depth of 15 km,and then decrease with increasing depth.When focal depth is less than 40 km,the order of magnitude of ocean loading tidal stress on faults is equivalent to that of solid tidal stress.Therefore,in studying tidal effect on the earthquakes with depth≤40 km in ocean area,it is necessary to consider the influence of ocean loading tidal stresses,besides the solid tidal stresses.
出处
《地震学报》
CSCD
北大核心
2010年第4期412-422,共11页
Acta Seismologica Sinica
基金
国家自然科学基金(40764001)资助
关键词
海潮负荷应力
地震断层
印尼地区
ocean loading tidal stress
earthquake fault
Indonesia region
