2016年新西兰Kaikoura Mw7.8地震动参数分布特征研究  

Spatial distribution of ground motion parameters during the 2016 Mw7.8 Kaikoura earthquake

作　　者：刘盼[1] 孙吉泽[2] 陈冬柏[1] LIU Pan;SUN Jize;CHEN Dongbai(Shaanxi Earthquake Agency,Xi’an 710068,China;Institute of Geophysics,China Earthquake Administration,Beijing 100081,China)

机构地区：[1]陕西省地震局,陕西西安710068 [2]中国地震局地球物理研究所,北京100081

出　　处：《地震工程与工程振动》2020年第3期223-227,共5页Earthquake Engineering and Engineering Dynamics

基　　金：陕西省地震局启航与创新基金项目(QC201814,QC201917);中国地震局“监测、预报、科研三结合”项目(3JH-201901070)。

摘　　要：2016年11月13日发生在新西兰的M w7.8地震是一起由多个破裂组成的复杂地震事件,地震持续时间长,滑移速率慢,辐射能少,使得整体的加速度峰值偏小。结合断层的滑移分布,对记录到的强地面运动进行分析发现,地震的影响范围主要集中在南岛东北部,具有很明显的方向性效应,断层沿着震中向东北方向进行滑动,在东西两侧的影响较小,沿断层滑动方向上地震动峰值大,CAV和Arias烈度也主要分布在沿着断层破裂方向上,具有两个明显峰值区,这和断层滑移量分布相一致,在断层滑移量影响范围外,Arias烈度和CAV迅速衰减到零,最大值都集中在最大破裂所在的WDFS台站附近。结合地震动预测方程进行分析发现,在100 km以内,地震动预测方程与PGA有较好的对应关系,但随着断层距的增加,在100 km以上,观测值逐渐低于地震动预测方程。综合研究表明,地震动参数主要受到断层滑移量和断层距的影响,且滑移量的影响要大于断层距的影响。The Kaikoura M w7.8 earthquake occurred in Novermber 13,2016,which is one of the most complex event included several rupture fault.The Kaikoura earthquake has long duration and slow slip velocity,so the radiated energy and the whole PGA record are small.In this study,we analyzed the strong motion records with distribution of rupture slip.The results indicated the influence of earthquake grouped in the north-eastern region of south-island and have obvious forward directivity effect.The faults slip from epicenter along the north-eastern direction and have small influences in east and west sides.The PGA,CAV and Arias intensity distribute along the slip direction and have same distribution with rupture slip which have two peak value areas,and the maximum value lies in the WDFS station.Comparison with the GMPE indicated that the PGA has good correspondence within 100 km,and beyond 100 km the observed PGA small than the GMPE.The research indicated that the parameters influenced by surface slip than the fault distance.

关 键 词：CAV Arias烈度 PGA Kailkoura地震 地震动 

分 类 号：P315.9[天文地球—地震学]