{"title":"Vertical deformation before and after the 2022 Menyuan Ms6.9 earthquake and analysis of earthquake precursors","authors":"Sixin Zhang, Peng Jia, Bowen Hou, Ming Hao","doi":"10.1016/j.geog.2023.03.005","DOIUrl":null,"url":null,"abstract":"<div><p>This study analyzed the vertical deformation before and after the 2022 Menyuan <em>M</em>s6.9 earthquake in Qinghai Province, China, using leveling profiles across faults measured from Minle County in Gansu Province to Menyuan County in Qinghai Province. Our results suggest the following: (1) The amplitude of regional vertical differential motion near the Sunna-Qilian and Lenglongling faults within the Qilian Shan increased before the 2022 Menyuan earthquake. It was accompanied by the emergence of high gradient deformation zones. Deformation at the Tongziba cross-fault leveling site near the Sunan-Qilian fault was considerable. In contrast, deformation at the Daliang cross-fault leveling site near the stepover region (adjacent to the epicenter) between the Lenglongling and Tuolaishan faults was minor. After 2018, vertical deformation at the Tongziba site notably accelerated, while that at the Daliang site was insignificant. (2) After the 2022 Menyuan earthquake, 140–150 mm of subsidence deformation occurred near the Daliang site, while the Tongziba site did not experience significant deformation. (3) Vertical deformation before and after the 2022 Menyuan earthquake conforms with the elastic-rebound theory, and the evolution of pre-earthquake deformation was consistent with the strike-slip fault deformation pattern at different seismogenic stages, i.e., the relative motion near the locked fault in the late seismogenic stage gradually weakened. The characteristics of strain accumulation and release derived from the vertical deformation before and after the Menyuan <em>M</em><sub>S</sub>6.9 earthquake help understand the deformation process of earthquake preparation and earthquake precursors.</p></div>","PeriodicalId":46398,"journal":{"name":"Geodesy and Geodynamics","volume":"14 6","pages":"Pages 582-588"},"PeriodicalIF":2.8000,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S167498472300037X/pdfft?md5=d62523c1580499065e85dc7d30b5ca0c&pid=1-s2.0-S167498472300037X-main.pdf","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Geodesy and Geodynamics","FirstCategoryId":"1089","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S167498472300037X","RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"GEOCHEMISTRY & GEOPHYSICS","Score":null,"Total":0}
引用次数: 0
Abstract
This study analyzed the vertical deformation before and after the 2022 Menyuan Ms6.9 earthquake in Qinghai Province, China, using leveling profiles across faults measured from Minle County in Gansu Province to Menyuan County in Qinghai Province. Our results suggest the following: (1) The amplitude of regional vertical differential motion near the Sunna-Qilian and Lenglongling faults within the Qilian Shan increased before the 2022 Menyuan earthquake. It was accompanied by the emergence of high gradient deformation zones. Deformation at the Tongziba cross-fault leveling site near the Sunan-Qilian fault was considerable. In contrast, deformation at the Daliang cross-fault leveling site near the stepover region (adjacent to the epicenter) between the Lenglongling and Tuolaishan faults was minor. After 2018, vertical deformation at the Tongziba site notably accelerated, while that at the Daliang site was insignificant. (2) After the 2022 Menyuan earthquake, 140–150 mm of subsidence deformation occurred near the Daliang site, while the Tongziba site did not experience significant deformation. (3) Vertical deformation before and after the 2022 Menyuan earthquake conforms with the elastic-rebound theory, and the evolution of pre-earthquake deformation was consistent with the strike-slip fault deformation pattern at different seismogenic stages, i.e., the relative motion near the locked fault in the late seismogenic stage gradually weakened. The characteristics of strain accumulation and release derived from the vertical deformation before and after the Menyuan MS6.9 earthquake help understand the deformation process of earthquake preparation and earthquake precursors.
期刊介绍:
Geodesy and Geodynamics launched in October, 2010, and is a bimonthly publication. It is sponsored jointly by Institute of Seismology, China Earthquake Administration, Science Press, and another six agencies. It is an international journal with a Chinese heart. Geodesy and Geodynamics is committed to the publication of quality scientific papers in English in the fields of geodesy and geodynamics from authors around the world. Its aim is to promote a combination between Geodesy and Geodynamics, deepen the application of Geodesy in the field of Geoscience and quicken worldwide fellows'' understanding on scientific research activity in China. It mainly publishes newest research achievements in the field of Geodesy, Geodynamics, Science of Disaster and so on. Aims and Scope: new theories and methods of geodesy; new results of monitoring and studying crustal movement and deformation by using geodetic theories and methods; new ways and achievements in earthquake-prediction investigation by using geodetic theories and methods; new results of crustal movement and deformation studies by using other geologic, hydrological, and geophysical theories and methods; new results of satellite gravity measurements; new development and results of space-to-ground observation technology.