龙门山中央断裂分段地震震级及强震复发周期的预测

摘要

After the Ms8.0 great earthquake occurred in the Longmen Mountains on May 12th, 2008, more and more geologists years focus attemtion on the seismic risk evaluation in the Longmen Mountains. In recent, to use quantitative and probability mathematical methods to assess the seismic risk in the active faults has been become a main research direction in the world. Based on studying the previous research achievements in active tectonic of the Yingxiu-Beichuan fault in the Longmen Mountains, measuring the offset dates of the surface ruptures of the Wenchuan earthquake, and making activity segmentations to the Yingxiu-Beichuan fault, this paper uses the calculation methods for earthquake magnitude to assess the magnitudes of the coming earthquakes in the Yingxiu-Beichuan fault and estimate the recurrence intervals of the strong earthquakes in Longmen Mountains. The results show that the estimations of the magnitudes are 7. 15±0. 35 in the Xuankou-Xiaoyudong segmentation, 7.36± 0. 33 in the Xiaoyudong-Leigu segmentation, 7.3±0.39 in the Leigu-Shikan segmentation, 7.62±0. 41 in the Yingxiu-Beichuan fault belt for the coming earthquakes, and the estimation of recurrence interval of the strong earthquakes is 1310~3932 a in Longmen Mountains.%汶川Ms8.0级地震发生后,对于龙门山发震构造带长期地震危险性评估的研究越来越受到了关注,以定量的、概率性的评估强活动断裂段的地震危险性也成为了近年来国际上研究长期地震预测的方向之一.作者以前人对龙门山中央断裂(映秀一北川断裂)活动构造的研究成果和汶川地震后地表特征的实测数据为依据,在对其进行活动分段的基础上,通过震级一标量参数经验关系武和强震重复间隔计算方法对中央断裂未来地震的可能震级及强震复发周期进行了定量计算,预估了中央断裂的分段地震震级、级联破裂地震震级以及龙门山构造带的强震复发周期.