{"title":"使用匹配定位方法表征2019年7月加利福尼亚州里奇克莱斯特MW6.4地震的前震","authors":"Min Liu , Miao Zhang , Hongyi Li","doi":"10.1016/j.eqs.2022.08.005","DOIUrl":null,"url":null,"abstract":"<div><p>The July 2019 <em>M</em><sub>W</sub>6.4 Ridgecrest, California earthquake and its distinct foreshocks were well recorded by local and regional stations, providing a great opportunity to characterize its foreshocks and investigate the nucleation mechanisms of the mainshock. In this study, we utilized the match-and-locate (M&L) method to build a high-precision foreshock catalog for this <em>M</em><sub>W</sub>6.4 earthquake. Compared with the sequential location methods (matched-filter + cross-correlation-based hypoDD), our new catalog contains more events with higher location accuracy. The <em>M</em><sub>W</sub>6.4 mainshock was preceded by 40 foreshocks within ∼2 h (on July 4, 2019 from 15:35:29 to 17:32:52, UTC). Their spatiotemporal distribution revealed a complex seismogenic structure consisting of multiple fault strands, which were connected as a throughgoing fault by later foreshocks and eventually accommodated the 2019 <em>M</em><sub>W</sub>6.4 mainshock. To better understand the nucleation mechanism, we determined the rupture dimension of the largest <em>M</em><sub>L</sub>4.0 foreshock by calculating its initial rupture and centroid points using the M&L method. By estimating Coulomb stress change we suggested that the majority of foreshocks following the <em>M</em><sub>L</sub>4.0 event and <em>M</em><sub>W</sub>6.4 mainshock occurred within regions of increasing Coulomb stress, indicating that they were triggered by stress transfer. The nucleation process before the <em>M</em><sub>L</sub>4.0 event remains unclear due to the insufficient sampling rate of waveforms and small magnitude of events. Thus, our study demonstrates that the M&L method has superior detection and location ability, showing potential for studies that require high-precision location (e.g., earthquake nucleation).</p></div>","PeriodicalId":46333,"journal":{"name":"Earthquake Science","volume":"35 4","pages":"Pages 213-242"},"PeriodicalIF":1.2000,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1674451922003524/pdfft?md5=1558c74ac87e7de2c140e14d932d9b2b&pid=1-s2.0-S1674451922003524-main.pdf","citationCount":"0","resultStr":"{\"title\":\"Using the match-and-locate method to characterize foreshocks of the July 2019 MW6.4 Ridgecrest, California earthquake\",\"authors\":\"Min Liu , Miao Zhang , Hongyi Li\",\"doi\":\"10.1016/j.eqs.2022.08.005\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>The July 2019 <em>M</em><sub>W</sub>6.4 Ridgecrest, California earthquake and its distinct foreshocks were well recorded by local and regional stations, providing a great opportunity to characterize its foreshocks and investigate the nucleation mechanisms of the mainshock. In this study, we utilized the match-and-locate (M&L) method to build a high-precision foreshock catalog for this <em>M</em><sub>W</sub>6.4 earthquake. Compared with the sequential location methods (matched-filter + cross-correlation-based hypoDD), our new catalog contains more events with higher location accuracy. The <em>M</em><sub>W</sub>6.4 mainshock was preceded by 40 foreshocks within ∼2 h (on July 4, 2019 from 15:35:29 to 17:32:52, UTC). Their spatiotemporal distribution revealed a complex seismogenic structure consisting of multiple fault strands, which were connected as a throughgoing fault by later foreshocks and eventually accommodated the 2019 <em>M</em><sub>W</sub>6.4 mainshock. To better understand the nucleation mechanism, we determined the rupture dimension of the largest <em>M</em><sub>L</sub>4.0 foreshock by calculating its initial rupture and centroid points using the M&L method. By estimating Coulomb stress change we suggested that the majority of foreshocks following the <em>M</em><sub>L</sub>4.0 event and <em>M</em><sub>W</sub>6.4 mainshock occurred within regions of increasing Coulomb stress, indicating that they were triggered by stress transfer. The nucleation process before the <em>M</em><sub>L</sub>4.0 event remains unclear due to the insufficient sampling rate of waveforms and small magnitude of events. Thus, our study demonstrates that the M&L method has superior detection and location ability, showing potential for studies that require high-precision location (e.g., earthquake nucleation).</p></div>\",\"PeriodicalId\":46333,\"journal\":{\"name\":\"Earthquake Science\",\"volume\":\"35 4\",\"pages\":\"Pages 213-242\"},\"PeriodicalIF\":1.2000,\"publicationDate\":\"2022-08-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://www.sciencedirect.com/science/article/pii/S1674451922003524/pdfft?md5=1558c74ac87e7de2c140e14d932d9b2b&pid=1-s2.0-S1674451922003524-main.pdf\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Earthquake Science\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S1674451922003524\",\"RegionNum\":4,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"Earth and Planetary Sciences\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Earthquake Science","FirstCategoryId":"89","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1674451922003524","RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"Earth and Planetary Sciences","Score":null,"Total":0}
Using the match-and-locate method to characterize foreshocks of the July 2019 MW6.4 Ridgecrest, California earthquake
The July 2019 MW6.4 Ridgecrest, California earthquake and its distinct foreshocks were well recorded by local and regional stations, providing a great opportunity to characterize its foreshocks and investigate the nucleation mechanisms of the mainshock. In this study, we utilized the match-and-locate (M&L) method to build a high-precision foreshock catalog for this MW6.4 earthquake. Compared with the sequential location methods (matched-filter + cross-correlation-based hypoDD), our new catalog contains more events with higher location accuracy. The MW6.4 mainshock was preceded by 40 foreshocks within ∼2 h (on July 4, 2019 from 15:35:29 to 17:32:52, UTC). Their spatiotemporal distribution revealed a complex seismogenic structure consisting of multiple fault strands, which were connected as a throughgoing fault by later foreshocks and eventually accommodated the 2019 MW6.4 mainshock. To better understand the nucleation mechanism, we determined the rupture dimension of the largest ML4.0 foreshock by calculating its initial rupture and centroid points using the M&L method. By estimating Coulomb stress change we suggested that the majority of foreshocks following the ML4.0 event and MW6.4 mainshock occurred within regions of increasing Coulomb stress, indicating that they were triggered by stress transfer. The nucleation process before the ML4.0 event remains unclear due to the insufficient sampling rate of waveforms and small magnitude of events. Thus, our study demonstrates that the M&L method has superior detection and location ability, showing potential for studies that require high-precision location (e.g., earthquake nucleation).
期刊介绍:
Earthquake Science (EQS) aims to publish high-quality, original, peer-reviewed articles on earthquake-related research subjects. It is an English international journal sponsored by the Seismological Society of China and the Institute of Geophysics, China Earthquake Administration.
The topics include, but not limited to, the following
● Seismic sources of all kinds.
● Earth structure at all scales.
● Seismotectonics.
● New methods and theoretical seismology.
● Strong ground motion.
● Seismic phenomena of all kinds.
● Seismic hazards, earthquake forecasting and prediction.
● Seismic instrumentation.
● Significant recent or past seismic events.
● Documentation of recent seismic events or important observations.
● Descriptions of field deployments, new methods, and available software tools.
The types of manuscripts include the following. There is no length requirement, except for the Short Notes.
【Articles】 Original contributions that have not been published elsewhere.
【Short Notes】 Short papers of recent events or topics that warrant rapid peer reviews and publications. Limited to 4 publication pages.
【Rapid Communications】 Significant contributions that warrant rapid peer reviews and publications.
【Review Articles】Review articles are by invitation only. Please contact the editorial office and editors for possible proposals.
【Toolboxes】 Descriptions of novel numerical methods and associated computer codes.
【Data Products】 Documentation of datasets of various kinds that are interested to the community and available for open access (field data, processed data, synthetic data, or models).
【Opinions】Views on important topics and future directions in earthquake science.
【Comments and Replies】Commentaries on a recently published EQS paper is welcome. The authors of the paper commented will be invited to reply. Both the Comment and the Reply are subject to peer review.