安徽霍山地区小地震时空特征研究  

Temporal and spatial characteristics of small earthquakes in Huoshan area,Anhui Province

作　　者：王鹏[1,2] 毕波 孙冬军[1,2] 邵永谦 刘芳 Wang Peng;Bi Bo;Sun Dongjun;Shao Yongqian;Liu Fang(Shanghai Earthquake Agency,Shanghai 200062,China;Shanghai Sheshan National Geophysical Observatory,Shanghai 200062,China)

机构地区：[1]上海市地震局,上海200062 [2]上海佘山地球物理国家野外科学观测研究站,上海200062

出　　处：《地震学报》2025年第1期93-106,共14页Acta Seismologica Sinica

基　　金：上海市科委社会发展科技攻关项目(23DZ1200200);上海市财政资助项目(2020J0001);上海佘山地球物理国家野外科学观测研究站海洋地震观测研究室课题(2023SSY08)共同资助。

摘　　要：利用基于人工智能算法PhaseNet的地震处理系统RISP,对安徽省霍山地区2020年7月至2022年8月连续两年的地震波形资料进行了扫描,检测到3839个地震事件,这一数量是人工目录的3倍。地震识别匹配率达到了95%。该系统能产出各震级段的地震目录,特别是震级ML-1.1—0.0段的微小地震,提升了该地区地震监测能力ML0.5,解决了人工目录缺乏ML0以下微震的问题。结合当地的地震监测能力,使用人工和RISP自动目录组合的新目录,进行tomoDD重新定位。结果表明,在落儿岭—土地岭断裂与磨子潭—晓天断裂的交会部位出现两个呈分段式丛集分布的地震条带,它们的优势分布方向与断裂的走向一致。北东向的BB′条带规模更大,其倾角近垂直。北西向的DD′条带规模相对较小,其倾角为65°—78°。BB′条带分为西南和东北两个部分,西南侧地震较少且震源较浅。而东北侧地震较多且震源的深度变化区间更大,倾角更陡。在平静期内霍山地区的地震没有明显的规律,但在2021年2月1日至10日密集地发生了641次地震,时间特征明显:地震先从断层面中间开始,然后向东北侧转移,最后转移至西南侧,表现出显著的地震活动迁移特征,可能是受流体控制作用的结果。The Huoshan area is located in the eastern part of the Chinese mainland,at the intersection of the Qinling-Dabie orogenic belt and the Tanlu seismic belt.The faults in the area are strongly active and earthquakes occur frequently.The main faults developed are the NE-trending Late Pleistocene active fault Luo’erling-Tudiling fault,the nearly EW-trending Mozitan-Xiaotian fault and Meishan-Longhekou fault.The NE-trending Luo’erling-Tudiling fault is the main earthquake-controlling and seismogenic structure.It cuts across the above-mentioned nearly EW-trending faults and passes through the North Dabie block,the North Huaiyang block and the Hefei basin from south to north.This region has always been a key monitoring area for earthquake prediction in the eastern part of China,often referred to as a“window”for studying stress field variations and seismic activity in the East China region.Acquiring a high-precision micro-seismic catalog for the Huoshan region is of significant importance in delineating fault morphology and seismic prediction.In this study,the seismic processing system RISP(real-time intelligent seismic processing system)based on the artificial intelligence algorithm PhaseNet was used to scan the continuous waveform data of Huoshan area from 2020 to 2022,ranging from(30.2°N—32.4°N,115°E—117.6°E).There are 21 seismic stations within 120 km of the Huoshan earthquake swarm.The seismic catalog was screened by parameters such as signal-to-noise ratio and phase(accuracy)probability,and an automatic catalog containing 3839 earthquakes was obtained.The number is three times that of the manual catalog.The RISP uses deep learning method to detect earthquakes,which includes phase picking,association,location and magnitude measurement.The system currently lacks the capability to identify non-natural earthquakes and locate tele-seismic events,leading to cases of non-natural earthquakes and misidentification of distant earthquakes as local events in the earthquake catalog.In addition to screening the ca

关 键 词：霍山震群 微震重定位 地震活动性 断裂构造 地震数据实时处理系统 双差定位与成像 

分 类 号：P315.31[天文地球—地震学]