SEISMOLOGY AND GEOLOGY ›› 2014, Vol. 36 ›› Issue (4): 1244-1259.DOI: 10.3969/j.issn.0253-4967.2014.04.024

• CONTENTS • Previous Articles     Next Articles

CAN THE DD-RELOCATED EARTHQUAKE CATALOGUE BE USED FOR THE STATISTICAL PARAMETERS OF AN EARTHQUAKE SEQUENCE?—A CASE STUDY OF THE SPATIAL DISTRIBUTION OF B-VALUES FOR THE AFTERSHOCKS OF THE 2014 LUDIAN MS6.5 EARTHQUAKE

ZHANG Sheng-feng, WU Zhong-liang, FANG Li-hua   

  1. Institute of Geophysics, China Earthquake Administration, Beijing 100081, China
  • Received:2014-12-09 Online:2014-12-30 Published:2015-01-07

双差(DD)定位地震目录能用于地震序列的统计地震学参数计算吗?——云南鲁甸MS6.5地震序列b值的空间分布

张盛峰, 吴忠良, 房立华   

  1. 中国地震局地球物理研究所, 北京 100081
  • 通讯作者: 吴忠良,研究员,E-mail:wuzl@cea-igp.ac.cn
  • 作者简介:张盛峰,男,1988年生,中国地震局地球物理研究所固体地球物理专业在读硕士研究生,研究方向为统计地震学,电话:13161076792,E-mail:zhangsf@cea-igp.ac.cn,085012104@163.com.
  • 基金资助:

    中国地震局"云南鲁甸6.5级地震专题研究"项目资助.

Abstract:

Relocated earthquake catalogue by double difference(DD)algorithm, while significantly improving the location precision, suffers from the degeneration of catalogue completeness. One of the questions subject to discussion is whether such DD-relocated catalogue is really an improvement, or otherwise a drawback, when calculating the spatially dependent statistical parameters of seismicity. In such statistical calculation, catalogue completeness is one of the key issues determining the quality of the result. Investigating this problem, this paper carries out a case study on the August 3, 2014, Ludian, Yunnan, MS6.5 earthquake sequence. Aftershocks within 40 days since the mainshock are analyzed using the routine catalogue provided by the national seismic network and a DD-relocated catalogue. The Gutenberg-Richter b-value, as well as its spatial distribution, from both catalogues, are calculated and compared. Results show that the degeneration of catalogue completeness of the DD-relocated catalogue depends on the clustering property of the earthquakes to much extent. Degeneration of catalogue completeness occurs at the margin of an earthquake cluster. Distribution of b-values based on the DD-catalogue provides clues to the source properties of the Ludian earthquake.

Key words: Ludian MS6.5 earthquake, b-value, aftershock sequence, double difference relocation

摘要:

双差(DD)定位后的地震目录, 较之地震台网给出的常规目录在精准度上有了提高, 但同时完整性也有一定的下降.DD目录能否用于统计地震学参数的计算? 在统计地震学参数的计算中, 目录完整性是一个最基本的问题.文中针对2014年8月3日云南鲁甸MS6.5地震后40天的余震序列, 对比分析了台网常规定位目录和一个DD目录, 比较了分别用2个目录得到的余震序列的b值, 讨论了DD目录用于计算b值等统计地震学参数的可信程度.结果表明, 对于地震序列, DD目录完整性的下降与地震丛集性质相关, 在地震丛集的边缘完整性明显下降, 但在丛集的内部下降程度较低.用DD定位后的序列分布, 讨论了鲁甸地震震源性质的相关问题.

关键词: 鲁甸MS6.5地震, b值, 余震序列, 双差定位

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