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

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1995年河北沙城ML4.1地震发震断层参数测定

陈学忠1, 王琼2, 刘冬英3   

  1. 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 ML4.1 Shacheng earthquake, Hebei Province

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

  1. 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: 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ML4.1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 ML4.1 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

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