利用濮阳小震集中区1970年1月-2019年12月地震目录，基于最邻近事件距离算法计算地震丛集率，分析该区地震丛集特征。结果发现：①在中强地震前，濮阳小震集中区地震丛集率存在高值现象，而后出现不同程度的低值，与强震前地震活动从增强到平静的过程相吻合，对地震危险区判定有一定指示意义；②1997年以来，4级以上地震主要分布在聊城-兰考断裂西侧，且小震出现相对"稀疏"异常，应给予关注。
Based on the earthquake catalogue from January 1970 to December 2019 in the small earthquake concentrated area of Puyang, the clustering rate of earthquakes is calculated based on the nearest event distance algorithm, and the clustering characteristics of earthquakes in the small earthquake concentrated area of Puyang are studied and analyzed. The results show that:① the clustering rate of small earthquakes in Puyang area is high before moderate earthquakes, which is often regarded as a signal of strong earthquakes or tectonic activities; and then there are low values in different degrees, which is consistent with the process of seismicity from enhancement to calm before strong earthquakes, and this feature has a certain indication significance for determining the seismic hazard area; ② Since 1997, earthquakes with M ≥ 4 are mainly distributed on the west side of Liaocheng-Lankao fault, and small earthquakes appear relatively "sparse" anomalies, which should be paid attention to.
2020,41(2): 51-56 收稿日期：2020-01-03
DOI：10.3969/j.issn.1003-3246.2020.02.007
基金项目：山东省地震局重点科研基金（项目编号：JJ1202Y）
作者简介：陈亚红(1975-),女,山东省菏泽市人,大学本科,高级工程师,主要从事地震活动性、预警研究工作。E-mail:lcyh_2008@163.com
参考文献：
陈亚红,郑建常,张军,申茂正,李铂,邵李娜. 濮阳小震集中区应力场跟踪分析[J]. 地震地磁观测与研究,2016,37(2):35-40.
林邦慧,胡小幸,王泽皋. 1966年邢台地区大震前小震的"密集-平静"特征及其初步解释[J]. 华北地震科学,2006,24(2):30-35.
梅世容. 地震前兆场物理模式与前兆时空分布机制研究(一)——坚固体孕震模式的由来与证据[J]. 地震学报,1995,17(3):273-282.
郑建常,吕子强,许萍,等. 濮阳小震集中区发震机理分析与讨论[J]. 中国地震,2013,29(1):11-25.
郑建常,李东梅,王鹏,等.基于最邻近事件距离算法的丛集地震识别方法及应用[J]. 地震,2014,34(4):100-109.
Zaliapin I, Gabrielov A, Keilis-Borok V, et al. Clustering analysis of seismicity and aftershock identification[J]. Physical Review Letters, 2008, 101(1):018501.
