樊倬^1,,
唐启家^1,2,,,
徐锐³,
刘江平^1,2
1. 中国地质大学(武汉)地球物理与空间信息学院, 武汉 430074
2. 中国地质大学(武汉)地球内部多尺度成像湖北省重点实验室, 武汉 430074
3. 四川省地震局, 成都 610041

基金项目: 国家自然科学基金青年基金项目（41704014）和四川省地震局科技创新团队计划（201803）联合资助


详细信息

作者简介: 樊倬, 男, 1993年生, 博士研究生, 主要从事天然地震学方面的研究.E-mail:13871331372@163.com

通讯作者: 唐启家, 男, 1980年生, 副教授, 主要从事地震触发、地震序列分析等研究.E-mail:iori89724@hotmail.com

中图分类号: P315

收稿日期:2018-03-12
修回日期:2019-11-17
上线日期:2020-01-05

Attenuation of horizontal earthquake ground motion in the southern segment of the north-south seismic belt, China

FAN Zhuo^1,,
TANG QiJia^1,2,,,
XU Rui³,
LIU JiangPing^1,2
1. Institute of Geophysics and Geomatics, China University of Geosciences, Wuhan 430074, China
2. Hubei Subsurface Multi-scale Imaging Key Laboratory, China University of Geosciences, Wuhan 430074, China
3. Sichuan Earthquake Agency, Chengdu 610041, China


More Information

Corresponding author: TANG QiJia,E-mail:iori89724@hotmail.com

MSC: P315

--> Received Date: 12 March 2018
Revised Date: 17 November 2019
Available Online: 05 January 2020


摘要
摘要:地震动衰减关系作为抗震救灾的重要依据，一直都是现代地震学研究的重点之一.本研究使用南北地震带南段区域2009-2016年共217个地震事件获得随震中距变化的水平向地震动峰值速度（PGV）和地震动峰值加速度（PGA）经验衰减关系，并计算场地响应.研究结果显示PGV衰减关系的拟合效果较PGA更好，两者的距离衰减系数会随事件矩震级增大呈线性减小；相较于大矩震级事件，中矩震级事件在近场可能产生较衰减关系理论值更大的PGV和PGA，同时衰减关系的拟合标准差会随事件矩震级的增大而减小.进行场地响应校正后的PGV和PGA更加符合经验衰减关系，PGA的场地响应影响较PGV更强但两者的趋势一致，并与该区域前人计算得到的地壳Q_s值分布对应，表明地壳介质放大或压制地震波振幅和其传递地震波能量的能力是相关联的.本文结果一定程度上揭示了南北地震带南段的地震动强度衰减特征，为未来中国西南部的抗震减灾工作提供了重要的参考.
关键词: 南北地震带南段/
衰减关系/
峰值速度/
峰值加速度/
场地响应

Abstract:Earthquake ground-motion attenuation can aids assessment of seismic hazards and is a focused subject in modern seismology. We used data of horizontal Peak Ground Velocity (PGV) and horizontal Peak Ground Acceleration (PGA) of 217 earthquakes that occurred during 2009-2016 in the southern segment of the north-south seismic belt to obtain attenuation relationships and site factors. Our results show that the discrepancies between observed and empirical-estimated PGV values are smaller than those of the PGA. Both PGV and PGA attenuation parameters decrease linearly with moment magnitude. Comparing with large earthquakes, moderate earthquakes may cause over-estimated PGV or PGA values near epicenters. The standard deviation of the attenuation regression decreases with growing moment magnitudes of earthquakes. To better improve the attenuation estimations, we further applied the site effect correlation to the PGV and the PGA data. The results show that site effects of PGA are stronger than those of the PGV. The variations of the PGV and the PGA site factors are consistent with the local crustal Q_s, suggesting that the amplitude amplifying of seismic waves in crust might be associated with the attenuation of energy propagation. This study reveals features of earthquake ground motion attenuation in the southern section of the north-south seismic belt and provides useful information for seismic hazard assessment in southwestern China.
Key words:Southern segment of north-south seismic belt/
Attenuation relationships/
Peak ground velocity/
Peak ground acceleration/
Site factors



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