摘要
由于青海地区中小地震活跃和区域地震监测能力明显提升,采用全国统一震群判别标准时,面临震群数量多、难以有效区分其预测意义和是否提取为异常等实际问题,急需建立适合青海震情特点的区域震群新标准。本文以1980年以来青海地区中小地震目录为研究对象,在全国测震学科组推荐的震群标准基础上,根据前人研究结果、区域震情特点、预报效能评价,经多次测试给出预测效能更好的区域震群新标准,即在青海地区仅挑选M_L≥3.0震群,将新的震群筛选方式纳入日常工作,为震情跟踪提供可靠的判定依据。此外,通过整理1980年以来青海及邻区M≥6.5地震发生前震群年频次,发现震前1—2年M_L≥2.0震群活动显著增强,表明该震群指标对该区M≥6.5地震有一定时间预测意义。
Due to the active occurrence of small and medium earthquakes and the significant enhancement of regional monitoring capabilities in Qinghai,using the national unified criteria for earthquake swarms has resulted in an excessive number of swarms.This makes it difficult to effectively distinguish their predictive significance and determine whether they should be extracted as anomalies.Therefore,it is urgent to establish a new regional earthquake swarms criteria suitable for the characteristics of Qinghai seismic activity.The paper aims to use the catalog of small and medium earthquakes in Qinghai since 1980 as the research object.Based on the earthquake swarm criteria recommended by the national seismology team,previous research results,regional seismic characteristics,forecast efficiency evaluation,and multiple tests,we propose new regional criteria for earthquake swarms with better predictive efficiency.According to the new criteria,only ML≥3.0 earthquake are selected in Qinghai,and we incorporate this new screening method into daily work to provide reliable judgment bases for earthquake tracking.In addition,by analyzing the annual frequency of earthquake swarms before M≥6.5 earthquakes in Qinghai and its adjacent areas since 1980,it was found that there is a significant increase in earthquake activity of ML≥2.0 one to two years before major earthquakes,indicating a certain temporal predictive significance for M≥6.5 earthquakes in the region.
作者
郭瑛霞
张丽峰
李启雷
胡维云
余娜
刘文邦
孙玺皓
GUO Yingxia;ZHANG Lifeng;LI Qilei;HU Weiyun;YU Na;LIU Wenbang;SUN Xihao(Qinghai Earthquake Agency,Xining 810001,China;Geodynamics Field Observation and Research Station of the Qinghai-Xizang Plateau,Xining 810001,China)
出处
《地震地磁观测与研究》
2024年第3期39-54,共16页
Seismological and Geomagnetic Observation and Research
基金
青海省地震科学基金项目(项目编号:2023A02)
2024年度震情跟踪定向工作任务(项目编号:2024010118)
2023年度震情跟踪定向工作任务(项目编号:2023010114)
青海省科技计划项目(应用基础研究计划)(项目编号:2023-ZJ-770)
青海格尔木青藏高原内部地球动力学野外科学观测研究站专项。
关键词
青海区域
震群活动
预测效能
预测指标
Qinghai region
earthquake swarm activities
prediction efficiency
predictive index
