摘要
较大的余震可能造成额外损失并有二次触发建筑物受灾的风险。为研究余震序列衰减规律,文章尝试采用指数衰减模型拟合分析5个不同地区余震序列,并借助修正赤池信息准则、贝叶斯信息准则与调整后R^(2),分析其与传统余震衰减模型的性能。结果表明,指数模型描述余震序列衰减规律的能力与修正的大森余震模型、修正的拉伸指数模型接近。尤其对于四川长宁M_(S)6.0余震序列和云南彝良M_(S)5.7余震序列,指数模型表现优于其他两种模型。指数模型参数具有明确的物理意义:参数A与r之和能够准确代表强震后的实际初始余震数,5个余震序列初始余震数偏差均小于1.70%;参数k可作为反映余震序列衰减快慢的特征值,k值越大则余震序列衰减越慢,其值与主震震级呈反比例关系。
Large aftershocks can cause additional losses and trigger the risk of building damage.To study the decay law of aftershock sequences,this paper attempts to use the exponential decay model to fit and analyze five aftershock sequences in various regions.The performances of the exponential and traditional aftershock decay models were analyzed using the corrected Akaike information criterion,Bayesian information criterion,and adjusted R^(2).The results show that the ability of the exponential model to describe the decay law of aftershock sequences is close to that of the modified Omori aftershock model and the stretched exponential model,especially the M_(S)6.0 aftershock sequence in Changning,Sichuan Province,and the M_(S)5.7 aftershock sequence in the Yiliang county of the Yunnan Province.In these two sequences,the exponential model performed better than the other two models,and the exponential model parameters showed clear physical meanings.The sum of parameters A and r can accurately represent the number of initial aftershocks after a strong earthquake.The deviations in the initial aftershock number of the five aftershock sequences are all less than 1.70%.The parameter k can be used as a characteristic value that reflects the decay rates of the aftershock sequences.The larger the value of k,the slower the decay of the aftershock sequence;and its values are inversely proportional to the magnitude of the main shock.
作者
徐世达
段俊康
何本国
刘佳奇
鲍泽铭
陈天晓
XU Shida;DUAN Junkang;HE Benguo;LIU Jiaqi;BAO Zeming;CHEN Tianxiao(Key Laboratory of Ministry of Education on Safe Mining of Deep Metal Mines,Northeastern University,Shenyang 110819,Liaoning,China)
出处
《地震工程学报》
CSCD
北大核心
2024年第1期207-213,共7页
China Earthquake Engineering Journal
基金
国家自然科学基金项目(62276058,51974059)
大创项目(220044)
中央高校基本科研业务费专项基金项目(N2217003,N2001001)。
关键词
余震序列
指数函数
初始余震数
衰减
aftershock sequence
exponential function
number of initial aftershocks
decay
