论文标题
脆性脱尿过渡区对余震和前壳发生的影响
The influence of the brittle-ductile transition zone on aftershock and foreshock occurrence
论文作者
论文摘要
余震发生的特征是具有相当通用的指数的缩放行为。同时，已经提出了与普遍性的偏差，以作为区分前换余震的工具。在这里，我们表明，从速度削弱到加强速度，地壳的流变行为的变化代表了一种可行的机制，可以解释余震和前锁的统计特征。更确切地说，我们提出了一个地震断层的模型，描述为速度削弱了弹性层，并耦合到增强粘弹性层的速度。我们表明，在定量级别恢复了仪器目录中余震的统计特性，这完全独立于模型参数的值。我们还发现，通常以前壳发生特征的预科阶段来期待大地震。它们的幅度分布明显比余震的分布明显，这与基于前锁的预测工具的最新结果一致。
Aftershock occurrence is characterized by scaling behaviors with quite universal exponents. At the same time, deviations from universality have been proposed as a tool to discriminate aftershocks from foreshocks. Here we show that the change in rheological behavior of the crust, from velocity weakening to velocity strengthening, represents a viable mechanism to explain statistical features of both aftershocks and foreshocks. More precisely, we present a model of the seismic fault described as a velocity weakening elastic layer coupled to a velocity strengthening visco-elastic layer. We show that the statistical properties of aftershocks in instrumental catalogs are recovered at a quantitative level, quite independently of the value of model parameters. We also find that large earthquakes are often anticipated by a preparatory phase characterized by the occurrence of foreshocks. Their magnitude distribution is significantly flatter than the aftershock one, in agreement with recent results for forecasting tools based on foreshocks.
