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地震 ›› 2020, Vol. 40 ›› Issue (4): 23-32.doi: 10.12196/j.issn.1000-3274.2020.04.002

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青海及邻区地震目录最小完整性震级分析

余娜, 张晓清, 杨晓霞   

  1. 青海省地震局, 青海 西宁 810000
  • 收稿日期:2020-01-07 出版日期:2020-10-30 发布日期:2020-10-23
  • 作者简介:余娜(1984-), 女, 青海民和人, 工程师, 主要从事数字地震资料的应用研究。
  • 基金资助:
    中国地震科学实验场专项(2019CSES0108); 2020年度青海省地震科学基金(2020A04)

Analysis of Minimum Magnitude of Completeness for Earthquake Catalog in Qinghai Region

YU Na, ZHANG Xiao-qing, YANG Xiao-xia   

  1. Earthquake Administration of Qinghai province, Xining 810000, China
  • Received:2020-01-07 Online:2020-10-30 Published:2020-10-23

摘要: 在强震多发且台站分布极不均匀的青海地区开展最小完整性震级分析, 对该地区的地震危险性分析具有重要的现实意义。 基于青海区域地震台网定位的地震目录, 利用“震级-序号”法和多参数方法分析了Mc的时间演化特征; 采用“完整震级范围”方法研究了其空间分布特征。 研究表明, 不同时段青海及邻区Mc的空间分布存在非均匀性, 其与测震台站的空间分布特征和分布密度具有较好的一致性。 2015年6月后祁连、 柴达木、 巴彦喀拉区域的东部区域最小完整性震级Mc较小, ML1.4以上的地震目录基本完整, 羌塘区域的最小完整性震级最大, 为ML2.5左右; 研究区的Mc随着测震台站数的增加、 台网布局的优化而降低。

关键词: 最小完整性震级, 震级-频度分布, 区域地震目录

Abstract: we study the minimum magnitude of completeness, Mc, in Qinghai region where strong earthquakes occur frequently and the seismostations are sparse and uneven. This works has practical significance to analyze the seismic risk in this area. Using “magnitude-rank” method to investigate the temporal variation of minimum magnitude of completeness, and the spatial distribution characteristics of minimum magnitude of completeness are studied by using “complete magnitude range” method. It is observed that in different stage, Mc is distributed inhomogeneously, which is in good agreement with the spatial distribution and distribution density of seismic stations. Since June 2015, the minimum magnitude of completeness in the eastern region of Qilian, Qaidam and Bayan Kara regions are smaller, the earthquake catalogue above ML1.4 is basically complete. But the minimum magnitude of completeness of Qiangtang region is something large and reached ML2.5 or more. The temporal variation of Mc for Qinghai region shows that the Mc decreases gradually with the optimization of the network and increasing of seismostations.

Key words: Minimum magnitude of completeness, Magnitude-frequency distribution, Location earthquake catalogue

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