川滇地区强震序列震级-破裂长度定标律特征研究  

Study on the Characteristics of Magnitude and Rupture-scale Calibration Law for Strong Earthquake Sequences in Sichuan-Yunnan Region

作　　者：王迪 冉喜阳 龙锋[1] 赵敏[1] 何畅[1] WANG Di;RAN Xiyang;LONG Feng;ZHAO Min;HE Chang(Sichuan Earthquake Agency,Chengdu 610041,Sichuan,China)

机构地区：[1]四川省地震局,四川成都610041

出　　处：《地震研究》2025年第3期370-381,共12页Journal of Seismological Research

基　　金：中国地震局监测预报司震情跟踪青年课题(2024010503);四川省地震局地震科技专项(LY2502,LY2201);地震科技星火计划攻关项目(XH23033A).

摘　　要：基于1970—2021年川滇地区M_(S)≥5.0地震序列数据,整理已发表的震源谱、地壳形变、余震分布等研究成果,获得125次地震的可靠破裂长度。采用最小二乘法,建立川滇地区震级-破裂长度的线性回归关系式。从震源机制解类型、不同区域构造环境、不同时间段3个方面分析了川滇地区强震序列定标律特征。研究发现,震级与破裂长度的对数之间存在线性关系,表现出错动类型以及时空差异性。结果表明:理论上在相同震级下,逆冲型地震的破裂长度小于走滑型地震的破裂长度;M_(S)≥6.5时,逆冲型地震的破裂长度大于正断型地震的破裂长度;M_(S)≥5.5时,走滑型地震的破裂长度大于正断型地震的破裂长度;孤立型地震序列的破裂长度低于同等级其他类型地震的破裂长度。地震监测台网高质量的观测对地震的破裂长度有着较好的约束。Based on the data of M_(S)≥5.0 earthquake sequences since 1970,and referring to the research results involving the source spectrum,the crustal deformation and the aftershock distribution in Sichuan-Yunnan region,we obtained the rupture-length of 125 earthquakes.Then we established the linear regression relation between the magnitude(M_(S))and the logarithm of the rupture-scale(lg L)in Sichuan-Yunnan region by using the least square method.Further,we analyzed the characteristics of this scaling law based on three aspects:the type of source mechanism solution,the regional structures and the different seismic periods.We found that this relation varies in the context of the type of seismic dislocation and the spatial and temporal difference of earthquakes.Theoretically,for the earthquakes with the same magnitude,the rupture length of the thrust earthquake should be shorter than that of the strike-slip earthquake.When M_(S)≥5.5,the rupture length of the strike-slip earthquake is longer than that of the positive fault earthquake.When M_(S)≥6.5,the rupture-length of thrust earthquake is longer than that of the normal fault earthquake.When their magnitudes are the same,the rupture length of the isolated-type earthquake is shorter than the ones of other types of earthquakes.In addition,the high-quality observational data of the seismic network play a decisive role in calculating the rupture-scale of the earthquakes.

关 键 词：川滇地区 定标律 破裂长度 地震序列 

分 类 号：P315.5[天文地球—地震学]