由宽频带辐射能量目录和地震矩目录给出的视应力及其地震学意义

Apparent Stress Obtained from Broadband Radiated Energy Catalogue and Seismic Moment Catalogue and Its Seismological Significance

对NEIC宽频带地震辐射能量目录和哈佛矩心矩张量 (CMT)目录的比较 ,给出关于视应力的一些可能是有意义的结果。尽管目前的结果误差仍很大 ,可靠性也是有限的 ,但这种比较所提供的线索却颇值得注意。视应力的计算给出关于地震断层面上非线性动摩擦函数的线索 ,能量 地震矩之比随地震大小的变化表明 ,在BK模型框架下 ,对于走滑型地震 ,依赖于滑动速度的摩擦似乎占主要地位 ;而对于非走滑型地震 ,依赖于位移的摩擦似乎占主要地位。主震和余震的能量 地震矩之比的比较表明 ,对于走滑型地震 ,余震的视应力平均地说来低于主震的视应力 ;而对于非走滑型地震 ,余震的视应力既有高于主震的也有低于主震的 ,这对于障碍体和凹凸体模式的讨论及模型中地震破裂停止条件的设置可能具有一定的参考意义。

Comparison between the NEIC broadband radiated energy catalogue and the Harvard CMT catalogue provides information about apparent stress. In spite of its significant uncertainties and limited reliability, the clues obtained from this comparison seem interesting in the physics of earthquakes. Scaling of apparent stress provides information about the dynamic friction along an earthquake fault in a Burridge\|knopoff spring\|block model. Relation between the energy/moment ratio and seismic moment implies that for strike slip earthquakes, velocity dependent friction plays a predominant role, while for non strike slip earthquakes, slip dependent friction is predominant. Comparison of energy/moment ratio for main shocks and aftershocks implies that for strike slip events, apparent stress of an aftershock is lower than that of the main shock, while for non strike slip events, apparent stress of an aftershock is higher than that of the main shock, a heuristic clue to the discussion of the barrier model and the asperity model and the stopping condition for a model earthquake fault.