1995年河北沙城ML4.1地震发震断层参数测定

地震 ›› 2005, Vol. 25 ›› Issue (2): 69-74.

1995年河北沙城M_L4.1地震发震断层参数测定

陈学忠¹, 王琼², 刘冬英³

1.中国地震局地球物理研究所, 北京 100081;
2.新疆维吾尔自治区地震局, 新疆乌鲁木齐 830011;
3.中国地震局地壳应力研究所, 北京 100085

收稿日期:2004-08-10 修回日期:2004-10-15 出版日期:2005-04-30 发布日期:2021-11-10
作者简介:陈学忠(1963-), 男, 重庆永川人, 研究员, 1995年获博士学位, 主要从事数学地震学、地震预测及前兆机理等研究。
基金资助:
地震科学联合基金项目(105004)

Fault plane determination for the 1995 M_L4.1 Shacheng earthquake, Hebei Province

CHEN Xue-zhong¹, WANG Qiong², LIU Dong-ying³

1. Institute of Geophysics, CEA, Beijing 100081;
2. Earthquake Administration of Xinjiang Uygur Autonomous Region, Urumqi 830011;
3. Institute of Crustal Stress, CEA, Beijing 100085, China

Received:2004-08-10 Revised:2004-10-15 Online:2005-04-30 Published:2021-11-10

摘要/Abstract

摘要： 在一维单侧有限移动震源模式下, 根据拐角频率的方位变化, 利用最小二乘法研究了1995年7月20日河北沙城M_L4.1地震的发震断层面参数。结果表明, 这次地震的断层面破裂方向为224°, 与余震分布和震源机制的NE向节面一致。地震马赫数v/c约为1.85, 即平均破裂速度大于S波速度, 为一次超速破裂。若取横波速度为3.5 km/s, 则破裂长度约为1 km。因此, 这次地震破裂以超S波速的速度从北东向西南方向传播了约1 km。

关键词: 拐角频率, 最小二乘法, 断层面参数, 地震马赫数

Abstract: By considering 1D finite moving source model propagating unilaterally, the corner frequency is employed to determine the azimuth of rupture propagation direction and source parameters of the July 20, 1995 M_L4.1 Shacheng Earthquake, Hebei Province, such as rupture direction, rupture velocity and fault length, by means of a least-squares approach. The results show that the azimuth angle of the fault plane for this event is about 224°, consistent with aftershock distribution and the NE nodal plane of focal mechanism solution. The seismic Mach number v/c is about 1.85, which means that the average rupture velocity is greater than that of S-wave. Given the velocity of S wave 3.5 km/s, the fault length is about 1.0 km. So the rupture propagated about a length of 1.0 km along the direction from NE to SW at a super velocity of S wave.

Key words: Corner frequency, Least-squares approach, Parameters of fault plane, Seismic Mach number

中图分类号:

P315.3

陈学忠, 王琼, 刘冬英. 1995年河北沙城M_L4.1地震发震断层参数测定[J]. 地震, 2005, 25(2): 69-74.

CHEN Xue-zhong, WANG Qiong, LIU Dong-ying. Fault plane determination for the 1995 M_L4.1 Shacheng earthquake, Hebei Province[J]. EARTHQUAKE, 2005, 25(2): 69-74.

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