多台阵反投影方法研究2016年厄瓜多尔M_W 7.8地震子事件及破裂过程

Sub-events and rupture process of the 2016 M_W 7. 8 Ecuador earthquake investigated by the multi-array back projection method

2016年4月17日,厄瓜多尔地区发生MW7.8的破坏性地震,震中位于0.353°N,79.925°W.为了得到此次地震详细的震源破裂过程,利用多台阵反投影方法,使用欧洲、北美中西部、阿拉斯加和南美四个台阵的远场P波垂直分量数据分别进行反投影,并将各个台阵的结果进行加权叠加后获得了本次地震的破裂时空分布.成像结果表明,此次地震是一次以向西南单侧破裂为主的事件,破裂持续时间约为50 s,总体破裂大致为边长为83 km的正方形区域.整个破裂过程包含四个子事件,其中能量最大的子事件位置位于震中以南65 km处.

An M_W7. 8 destructive earthquake occurred in Ecuador on 17 April,2016. Its epicenter is located at 0. 353° N,79. 925° W.In order to investigate the rupture process of this earthquake in detail,the vertical component data of tele-seismic P waves recorded by South America,Europe,the west and central North America and Alask aarrays are used to resolve the rupture process using an robust multi-array back projection method. The result indicates that the earthquake has a unilateral rupture process with orientation of Southwest,the duration of the process is about 50 seconds and rupture area is about 83 km times 83 km. The rupture process can be divided into four stages,which respectively represent four subevents,among which the largest one is located about 65 km south of the epicenter.