Multiasperity fault model and the nature of short-period subsources
Multiasperity fault model and the nature of short-period subsources
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多粗糙断层模型和短周期子源的性质
DOI：
10.1007/bf00881602
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发表时间：
1989
影响因子：
2
通讯作者：
A. Gusev
中科院分区：
文献类型：
--
作者：
A. Gusev
我们建议考虑打破一个严酷的，即。断层壁之间的小接触片，作为一个典型的子源，从一个大震源产生一个基本的短周期辐射脉冲。在das和kostrov的研究结果的基础上，我们提出了描述多陡断层/源模型加速度振幅和谱的公式。粗糙体上的应力降由几种方式决定；估计的平均值为几百巴。相似凸起情况下的理论加速度谱形状与观测值一致，它们再现了低频斜率、峰值和高频截止等特征。讨论了凸点总体上的统计应力降分布，以及相应的峰值加速度分布。这些分布是指数接近于2的幂律分布。这意味着加速度峰值通常是由单个凸起的断裂形成的。我们认为小地震是由单个岩石破碎产生的，这一思想解释了观测到的加速度谱上截止频率与小地震典型特征频率之间的相关性。
We suggest to consider the breaking of an asperity,i.e., a small contact patch between fault walls, as a typical subsource producing an elementary short-period radiation pulse from a source of a large earthquake. Based on the results ofDas andKostrov we propose formulas to describe amplitudes and spectra of acceleration for a multiasperity fault/source model. The stress drop over an asperity is determined in several ways; the estimates agree to give the average value of several hundred bar. Theoretical acceleration spectral shapes for the case of similar asperities agree with the observed ones, they reproduce such features as lower-frequencyf1 slope, peak, and high-frequency cutoff. The statistical stress-drop distribution over the population of asperities, and also the related distribution of peak accelerations are discussed. There distributions are found to be the power-law ones with exponent near to 2. This means that acceleration peaks are formed normally by breaking of individual asperities. We consider small earthquakes as produced by breaking of single asperities, this idea explains the observed correlation between the upper cutoff frequency of acceleration spectrum and the typical characteristic frequency of small earthquakes.