2013年4月20日四川芦山地震震源破裂过程反演初步结果

使用远场体波资料和有限断层方法快速反演获得了2013年4月12日芦山地震的震源破裂过程模型,并计算了震中区理论烈度分布.结果显示这次地震是发生在龙门山断裂带南端的一次M_w6.7级的逆冲型地震,最大滑动量159 cm,震中区烈度达Ⅷ-IX度(中国地震烈度表).这次地震的震源性质与汶川地震同为逆冲型破裂,主要破裂滑动发生在汶川地震后的库伦应力增加区域,表明汶川地震对这次地震有触发效应,在宏观上可视为汶川地震一次"迟到"的强余震.

Preliminary result for rupture process of Apr.20, 2013, Lushan Earthquake, Sichuan, China

The rupture process of the 20, Apr. 2013, Lushan earthquake was fast estimated by finite fault model method using far field body waveform records. The predicted shakemap is subsequently calculated based on rupture fault model of this earthquake. Results show that the earthquake is an M_w6.7 thrusting event which occurred on the south part of Longmen Shan fault zone with 159 cm largest slip. By the predicted shakemap, the intensity of epicenter region should reached Ⅷ-IX on Chinese seismic intensity scale. The thrusting mechanism of Lushan earthquake is similar to that of Wenchuan earthquake. The earthquake rupture of this event occurred on the southern section of Longmen Shan fault where shows increase of Coulomb stress caused by the Wenchuan earthquake. This event may be triggered by the Wenchuan earthquake. On the view of macroscopic, this earthquake can be considered as an delayed strong aftershock of Wenchuan earthquake.