王亚文, 蒋长胜. 2017: 南北地震带地震台网监测能力评估的不同方法比较研究. 地震学报, 39(3): 315-329. DOI: 10.11939/jass.2017.03.002
引用本文: 王亚文, 蒋长胜. 2017: 南北地震带地震台网监测能力评估的不同方法比较研究. 地震学报, 39(3): 315-329. DOI: 10.11939/jass.2017.03.002
Wang Yawen, Jiang Changsheng. 2017: Comparision among different methods for assessing monitoring capability of seismic station in North-South Seismic Belt. Acta Seismologica Sinica, 39(3): 315-329. DOI: 10.11939/jass.2017.03.002
Citation: Wang Yawen, Jiang Changsheng. 2017: Comparision among different methods for assessing monitoring capability of seismic station in North-South Seismic Belt. Acta Seismologica Sinica, 39(3): 315-329. DOI: 10.11939/jass.2017.03.002

南北地震带地震台网监测能力评估的不同方法比较研究

Comparision among different methods for assessing monitoring capability of seismic station in North-South Seismic Belt

  • 摘要: 为探讨不同地震台网监测能力评估方法的结果差异性及其原因,本文选用目前国际上比较前沿的“基于概率的完整性震级”(PMC)方法和“完整性震级范围”(EMR)方法,以及中国地震台网常规采用的“震级-最大距离”方法,对2008年10月1日—2015年9月17日南北地震带地区表征地震监测能力的最小完整性震级进行了比较研究.研究中考虑了以往关注不够的地震观测质量一致性问题,统一采用至少3个台站记录的地震资料.结果显示,3种方法的结果差异显著,最小完整性震级的差值在南北地震带个别地区甚至可达ML2.0,其中,PMC方法获得的最小完整性震级Mp值在32°N以北地区显著低于其它两种方法,震级-最大距离方法获得的最小完整性震级Mr低值结果仅与高台站密度地区有关,与包括EMR方法获得的最小完整性震级McEMR相比较在统计均值上则呈McEMR < Mp < Mr.进一步对各地震台站的地震检测能力进行评分,结果显示,台站运维水平和对记录地震分析的完整程度,是造成Mp值显著不同于其它方法结果的主要原因,而是否选用相同的记录台站数量等数据质量约束标准,会造成EMR方法与其它方法结果的显著差异.因此,考虑到地震台网运行的实际情况和不同评估方法的计算原理,推荐PMC方法用于地震监测能力的评估.

     

    Abstract: In order to explore the differences and causes of the methods for assessing monitoring capability of different seismic networks, this paper chooses the "probability-based magnitude of completeness" (PMC) and "entire-magnitude-range"(EMR) methods which are the relatively frontier in the world, and the "magnitude-maximum distance" method applied routinely in China Seismic Networks to compare minimum magnitude of completeness (marked as Mp, McEMR and Mr, respectively, obtained by the above three methods) in the North-South Seismic Belt region during the time span from 1 October 2008 to 17 September 2015. The consistency of data observation quality is also considered, which is not paid enough attention in previous studies, and the selected seismic events are recorded by at least three stations. The results show that the assessing results of the three methods are significant different, and the difference between any two methods can reach to ML2.0 for some specific positions in the North-South Seismic Belt. The Mp result is significantly lower than the results by the other two methods in the region to the north of 32°N, low Mr value by the magnitude-maximum distance method is only related to the higher density seismic station region. In general the statistical relationship is McEMR < Mp < Mr. Furthermore, the detection capability score results reveal that the station operational level and the completeness in earthquake record analyses are the main reasons that the Mp significantly differs from the results calculated by other methods, and data quality constraint criteria such as the amount constraint of recorded stations whether used or not, will cause significantly different results of the EMR method from other methods. Considering practical situation of the seismic network in operation and calculation principles of the three assessment methods, the PMC method is more reasonable and recommended for earthquake monitoring ability assessment work.

     

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