安徽"霍山窗"中小地震的 地震波衰减特征研究

李发, 黄显良, 陈宇卫, 沈小七, 刘泽民

李发, 黄显良, 陈宇卫, 沈小七, 刘泽民. 2013: 安徽"霍山窗"中小地震的 地震波衰减特征研究. 地震学报, 35(2): 209-217. DOI: 10.3969/j.issn.0253-3782.2013.02.007
引用本文: 李发, 黄显良, 陈宇卫, 沈小七, 刘泽民. 2013: 安徽"霍山窗"中小地震的 地震波衰减特征研究. 地震学报, 35(2): 209-217. DOI: 10.3969/j.issn.0253-3782.2013.02.007
Li Fa, Huang Xianliang, Chen Yuwei, Shen Xiaoqi, Liu Zemin. 2013: Study on attenuation characteristics of seismic waves from small-moderate earthquakes in “Huoshan seismic window”, Anhui Province. Acta Seismologica Sinica, 35(2): 209-217. DOI: 10.3969/j.issn.0253-3782.2013.02.007
Citation: Li Fa, Huang Xianliang, Chen Yuwei, Shen Xiaoqi, Liu Zemin. 2013: Study on attenuation characteristics of seismic waves from small-moderate earthquakes in “Huoshan seismic window”, Anhui Province. Acta Seismologica Sinica, 35(2): 209-217. DOI: 10.3969/j.issn.0253-3782.2013.02.007

安徽"霍山窗"中小地震的 地震波衰减特征研究

基金项目: 安徽省地震局科研基金(201109)资助.
详细信息
    通讯作者:

    李发, E-mail:uuujerry@yahoo.com.cn

  • 中图分类号: P315.3+1

Study on attenuation characteristics of seismic waves from small-moderate earthquakes in “Huoshan seismic window”, Anhui Province

  • 摘要: 利用安徽合肥台、 六安台和豹子崖台记录到的2001—2010年安徽“霍山窗”发生的ML≥2.0地震的波形资料, 计算了其振幅衰减系数K值和卓越频率衰减系数a值, 分析研究了K值和a值的时空变化特征, 并讨论了其与华东地区中强地震的对应关系及与Qc值的相关性. 结果表明, 3个台站均记录到了明显的变化特征: ① “霍山窗”ML4.0地震、 江西九江MS5.7地震及河南太康ML5.0地震前6个月左右时间内, K值和a值均呈现持续下降的异常低值状态, 平均下降幅度K值为20%—35%, a值为45%—51%, 并于上升的过程中发震, 震后趋于正常; ② K值的平面分布特征显示, K值异常地震主要位于断裂带交汇区附近, 并沿断裂带方向分布; ③ K值、 a值与Qc值基本呈负相关. 上述特征为进一步了解该区域的地壳介质状态和研究中强震前后Qc的变化特征提供了一定的依据. 该研究结果可能对中长期地震预报和震后趋势判断有一定的指示意义.
    Abstract: Based on the waveform data from ML≥2.0 earthquakes during 2001—2010 in Anhui “Huoshan seismic window” recorded by Hefei, Lu’an and Baoziya stations of Anhui Digital Seismic Network, the amplitude attenuation coefficient K and the predominant frequency attenuation coefficient a were calculated, their temporal and spatial variations were analyzed, and the possible relationship of the variations with moderate-strong earthquake occurrence in eastern China and coda Qc were discussed. The results indicate the following variation characteristics: ① In about six months before the ML4.0 earthquake in “Huoshan seismic window”, the MS5.7 Jiangxi Jiujiang earthquake and the ML5.0 Henan Taikang earthquake, K value and a value decreased continuously to an abnormally low state; the average rates of decrease for K and a are 20%—35% and 45%—51%, respectively; the earthquakes occurred during the rising process of K and a values. ② By inspecting the plane view of K variation, we found that earthquakes with abnormal K value are mainly located at or near the fault intersections and distributed along fault zones. ③ K and a values basically showed negative correlation with coda Qc value, providing certain basis for further studying Qc variation before and after moderate-strong earthquakes.
  • 图  1   测量方法示意图. (a) 数据点选取实例; (b) 卓越频率量取实例

    Figure  1.   A sketch of measurement method (a) An example of data selection; (b) An example of predominant frequency measurement

    图  2   “霍山窗”内外中小地震、 记录台站和地质构造分布图

    Figure  2.   Small-moderate earthquakes,seismic stations and geological faults inside and outside “Huoshan seismic window”

    图  3   3个台站K值的时间变化曲线

    Figure  3.   Temporal variation of K value at the 3 stations

    图  4   3个台站a值的时间变化曲线

    Figure  4.   Temporal variation of a value at the 3 stations

    图  5   豹子崖台的K值平面分布

    Figure  5.   K-value distribution around Baoziya station

    图  6   “霍山窗”外围地震的K值平面分布

    Figure  6.   Distribution of K values of earthquakes outside “Huoshan seismic window”

    图  7   K值(a)、 a值(b)与Qc值的关系图

    Figure  7.   Variation of Qc with K value (a) and with a value (b)

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出版历程
  • 收稿日期:  2011-12-20
  • 修回日期:  2012-02-26
  • 发布日期:  2013-02-28

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