非线性混合模型的优越性及其在中国典型地震强活动区的应用  

The advantage of the nonlinear mixed model and its application in typical seismically active areas in China

作　　者：周汉杨 杜建军[1,2,3] 张舒婷 ZHOU Hanyang;DU Jianjun;ZHANG Shuting(Institute of Geomechanics,Chinese Academy of Geological Sciences,Beijing 100081,China;Key Laboratory of Active Tectonics and Geological Safety of Natural Resources,Beijing 100081,China;Research Center of Neotectonism and Crustal Stability,China Geological Survey,Beijing 100081,China;Oil and Gas Resources Strategic Research Center of the Ministry of Natural Resources of the People’s Republic of China,Beijing 100037,China)

机构地区：[1]中国地质科学院地质力学研究所,北京100081 [2]自然资源部活动构造与地质安全重点实验室,北京100081 [3]中国地质调查局新构造与地壳稳定性研究中心,北京100081 [4]自然资源部油气资源战略研究中心,北京100037

出　　处：《地质力学学报》2023年第2期264-275,共12页Journal of Geomechanics

基　　金：中国地质调查局地质调查项目(DD20221644)。

摘　　要：b值作为地震预报与危险性评价研究中的重要参数,受到广泛关注与讨论。通过非线性混合模型对中国地震目录数据库开展地震震级-频数分布拟合,并利用该方法计算得到的b值对地震活动进行分析评价。文章首先以中国26个地震带为研究区,收集1920—2019年的4.7级以上地震数据为完整地震目录,分别通过非线性混合模型与传统G-R模型进行拟合,并对比其效果;进一步以西藏地区为具体试验区,选择1920—2019年的地震目录数据,以10年为间隔,将非线性混合模型应用于西藏地区地震震级-频数模型的拟合。其次,利用矩震级与地震矩转换公式计算出非线性混合模型中的相关变量。最后,利用非线性混合模型对地震数据进行非线性回归分析。结果显示:当b值出现低值时,对应时间段前后有地震发生,b值较低时,发生的地震震级大、频次底;b值相对较高时,地震震级小、频次高。将非线性混合模型应用到中国及邻区完整地震数据中,能够对数据进行更加全面的分析,克服了传统模型方法对高震级和地震数据分析中的局限性,合理分析计算b值,进而增强对地震目录数据的分析和评价。As an essential parameter in earthquake prediction and risk assessment research,the b-value has received extensive attention and discussion.In this study,we chose a nonlinear mixed model to fit the earthquake magnitude-frequency distribution to the China Earthquake Catalog database.The b-values calculated by this method were used to analyze and evaluate the seismic activity.This paper takes 27 seismic belts in China as the research area,collects earthquake data of magnitude 4.7 and above from 1920 to 2019 as a complete earthquake catalog,performs mixed model fitting and G-R model fitting for these 27 seismic belts,and compares the fitting effects.Taking Tibet as the test area,the earthquake catalog data from 1920 to 2019 were selected,and the nonlinear mixed model was applied to fitting the earthquake magnitude-frequency model in Tibet at 10-year intervals.Firstly,the earthquake data screened in the study area was classified and counted by magnitude and time;Secondly,the relevant variables in the nonlinear mixed model were calculated using the moment magnitude and seismic moment conversion formula.Finally,a nonlinear hybrid model was used to perform nonlinear regression analysis on the seismic data.The results show that:When low values of b occur,earthquakes occur around the corresponding periods.When b-values are low,earthquakes of large magnitude and low frequency occur.When bvalues are relatively high,earthquakes of small magnitude and high frequency occur.Applying the nonlinear mixed model to the complete seismic data in China and neighboring regions enables a more comprehensive analysis of the data and overcomes the limitations of the traditional modeling method in analyzing earthquakes of high magnitude.The b-value will be calculated by rational analysis,which enhances the analysis and evaluation of seismic catalog data.

关 键 词：非线性混合模型 B值 地震震级-频率分布 

分 类 号：P315[天文地球—地震学]