汶川8.0级地震最大余震的强度估计

Estimating Magnitude of Maximum Aftershock of the Wenchuan M_S8.0 Earthquake

基于对古登堡—里克特震级频度关系的理解,提出估计地震序列最大余震强度的思路:(1)根据主震发生后数天的地震序列目录,得到该序列的衰减系数P值和震级频度关系b值;(2)估计该序列结束时可能的余震总次数;(3)依据该序列的b值和估计的余震总次数,按古登堡—里克特震级频度关系估计最大余震的强度。将该思路应用于汶川8.0级地震最大余震的震级估计,结果显示:按该思路估计的最大强余震的震级可能比仅根据已发生地震得到的震级更接近实际情况。

We present a method to estimate the magnitude of the maximum aftershock through the Gutenberg-Richter relation.The b value and damping coefficient P value of aftershock sequence are calculated in terms of the aftershock sequence several days after mainshock.The magnitude of the maximum aftershock is given by the Gutenberg-Richter relation based on calculated b value and the estimated total number of aftershocks of whole sequence.We use the method to estimate the maximum aftershock of the Wenchuan MS8.0 earthquake.The estimated magnitude more agrees with the real one than the result only based on the occurred aftershocks.