| 2017年漾濞MS4.8和MS5.1地震序列的微震检测及重定位 |
| |
| 引用本文： | 李姣,姜金钟,杨晶琼.2017年漾濞MS4.8和MS5.1地震序列的微震检测及重定位[J].地震学报,2020,42(5):527-542. |
| |
| 作者姓名： | 李姣 姜金钟 杨晶琼 |
| |
| 作者单位： | 中国昆明 650224 云南省地震局 |
| |
| 基金项目： | 云南省地震局科技专项基金（2018ZX01）和青年基金（2019K01）、云南省科技计划项目基础研究青年项目（2018FD158）及云南省地震局科技人员传帮带项目（C2-201703）共同资助 |
| |
| 摘 要： | 基于云南地震台网记录到的2017年漾濞MS4.8和MS5.1地震序列的地震目录和波形数据，采用结合波形互相关的双差定位方法得到了MS5.1主震前7天至主震后30天共258次地震事件更加准确的震源位置，然后利用匹配定位方法获得了更加丰富的地震目录，并对其余震活动的时空演化特征进行了初步分析。双差重定位获得了漾濞地震序列中193次地震的精确位置，水平方向和垂直方向的定位误差均值分别为1.3 km和1.9 km，重定位及震源机制解反演结果显示维西—乔后断裂中南段应为此次地震的发震断层。使用匹配定位方法检测得到了1 625次中小地震事件，事件数量是云南地震台网目录中的6倍，被检测事件主要为主震后早期余震及ML≤0微震事件。对比2016年云龙MS5.0地震序列的研究结果后初步分析认为，“震群（多震）型”和“主余型”地震序列的一个主要区别可能是“震群（多震）型”地震序列的余震数量相对更少、余震活动衰减得更快。
|
| 关 键 词： | 2017年漾濞MS4.8和MS5.1地震序列 双差定位 波形互相关 地震检测 匹配定位方法 |
| 收稿时间： | 2019-11-01 |
Microseismic detection and relocation of the 2017 MS4.8 and MS5.1 Yangbi earthquake sequence，Yunnan |
| |
| Affiliation: | Yunnan Earthquake Agency，Kunming 650224，China |
| |
| Abstract: | Based on the earthquake catalog and waveforms of 2017 MS4.8 and MS5.1 Yangbi earthquake sequence recorded by Yunnan Seismic Network, we relocate 258 earthquakes occurring one week before and one month after the Yangbi MS5.1 mainshock by simultaneously using P- and S-wave travel times and waveform cross-correlation data in the double-difference relocation. We then use the 258 earthquakes as template events and scan through the continuous waveforms to search for weak events by using the match and locate method. Using our new catalog, we preliminarily analyze the spatio-temporal evolution characteristics of Yangbi earthquake sequence. We obtain refined hypocenters of 193 earthquakes with location errors of about 1.3 km in the horizontal direction and 1.9 km in the depth, respectively. According to the double-difference relocation and focal mechanisms of the mainshock and early ML≥3.0 aftershocks, we preliminarily conclude that the middle-south segment of the Weixi-Qiaohou fault may account for the occurrence of the MS5.1 Yangbi earthquake. A total of 1 625 events are detected by 258 template events, which is about six times as many as the events of Yangbi earthquake sequence listed in the Yunnan Seismic Network catalog. And the detected events are mainly the early aftershocks and ML≤0 micro events. By comparison with the 2016 MS5.0 Yunlong earthquake, we conclude that less number and faster decay of aftershocks may be the main difference between the multiple mainshock type of sequence and the mainshock-aftershock type of sequence. |
| |
| Keywords: | |
|
| 点击此处可从《地震学报》浏览原始摘要信息 |
|
点击此处可从《地震学报》下载全文 |
