Coseismic deformation and slip model of the 2024 MW7.0 Wushi earthquake obtained from InSAR observation

On January 23, 2024, an MW7.0 earthquake occurred in Wushi County. This earthquake was the largest earthquake event in the south Tianshan Fault Zone in the past century. In order to determine the seismogenic structure of the Wushi earthquake and analyze the regional tectonic stress characteristics,...

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Main Authors: Lei Zhao, Zhidan Chen, Lei Xie, Zhihui Zhu, Wenbin Xu
Format: Article
Language:zho
Published: Editorial Office of Reviews of Geophysics and Planetary Physics 2024-07-01
Series:地球与行星物理论评
Subjects:
Online Access:https://www.sjdz.org.cn/en/article/doi/10.19975/j.dqyxx.2024-010
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author Lei Zhao
Zhidan Chen
Lei Xie
Zhihui Zhu
Wenbin Xu
author_facet Lei Zhao
Zhidan Chen
Lei Xie
Zhihui Zhu
Wenbin Xu
author_sort Lei Zhao
collection DOAJ
description On January 23, 2024, an MW7.0 earthquake occurred in Wushi County. This earthquake was the largest earthquake event in the south Tianshan Fault Zone in the past century. In order to determine the seismogenic structure of the Wushi earthquake and analyze the regional tectonic stress characteristics, we obtained the coseismic deformation field using radar interferometry and pixel offset based on Sentinel-1A data, and estimated the optimal fault geometric parameters applying the Bayesian nonlinear inversion. The results show that the maximum ascending line-of-sight uplift displacement is ~80 cm, and the maximum line-of-sight subsidence is ~16 cm. The line-of-sight coseismic deformation and pixel offsets indicate the significant vertical deformation characteristics of the Wushi earthquake, while the reverse pixel offset results in the azimuth direction of the ascending and descending orbit indicate obvious left-lateral strike-slip on the seismogenic fault. The inversion results show that the seismogenic fault of the Wushi earthquake is SW trending, NW dipping, with an optimal fault dip angle of ~67° and an average rake angle of ~60°, indicating that the coseismic slip is mainly driven by thrust-slip motion with a minor left-lateral strike-slip component. The deformation pattern and fault geometry parameters of the Wushi earthquake are consistent with the kinematics and geometry of the Maidan-Shayilamu fault at the basin-mountain boundary in the southern margin of the Tianshan Mountains. The high dip angle fault with strike- and thrust-slip activity of the Wushi earthquake indicates oblique convergence between the southern Tianshan Mountains and the Tarim Basin, and emphasizes that crustal shortening in the Tianshan region is absorbed by the nascent thrust nappe belts in the piedmont areas and the reverse faults with high dip angles in the orogenic regions.
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spelling doaj.art-c7e7ca563c0f40c39a5dce945d0a24c02024-04-10T09:03:04ZzhoEditorial Office of Reviews of Geophysics and Planetary Physics地球与行星物理论评2097-18932024-07-0155445346010.19975/j.dqyxx.2024-0102024-010Coseismic deformation and slip model of the 2024 MW7.0 Wushi earthquake obtained from InSAR observationLei Zhao0Zhidan Chen1Lei Xie2Zhihui Zhu3Wenbin Xu4School of Geoscience and Info-Physics, Central South University, Changsha 410083, ChinaSchool of Geoscience and Info-Physics, Central South University, Changsha 410083, ChinaSchool of Geoscience and Info-Physics, Central South University, Changsha 410083, ChinaSchool of Civil Engineering, Central South University, Changsha 410075, ChinaSchool of Geoscience and Info-Physics, Central South University, Changsha 410083, ChinaOn January 23, 2024, an MW7.0 earthquake occurred in Wushi County. This earthquake was the largest earthquake event in the south Tianshan Fault Zone in the past century. In order to determine the seismogenic structure of the Wushi earthquake and analyze the regional tectonic stress characteristics, we obtained the coseismic deformation field using radar interferometry and pixel offset based on Sentinel-1A data, and estimated the optimal fault geometric parameters applying the Bayesian nonlinear inversion. The results show that the maximum ascending line-of-sight uplift displacement is ~80 cm, and the maximum line-of-sight subsidence is ~16 cm. The line-of-sight coseismic deformation and pixel offsets indicate the significant vertical deformation characteristics of the Wushi earthquake, while the reverse pixel offset results in the azimuth direction of the ascending and descending orbit indicate obvious left-lateral strike-slip on the seismogenic fault. The inversion results show that the seismogenic fault of the Wushi earthquake is SW trending, NW dipping, with an optimal fault dip angle of ~67° and an average rake angle of ~60°, indicating that the coseismic slip is mainly driven by thrust-slip motion with a minor left-lateral strike-slip component. The deformation pattern and fault geometry parameters of the Wushi earthquake are consistent with the kinematics and geometry of the Maidan-Shayilamu fault at the basin-mountain boundary in the southern margin of the Tianshan Mountains. The high dip angle fault with strike- and thrust-slip activity of the Wushi earthquake indicates oblique convergence between the southern Tianshan Mountains and the Tarim Basin, and emphasizes that crustal shortening in the Tianshan region is absorbed by the nascent thrust nappe belts in the piedmont areas and the reverse faults with high dip angles in the orogenic regions.https://www.sjdz.org.cn/en/article/doi/10.19975/j.dqyxx.2024-010wushi earthquakecoseismic deformationcoseismic slip distributionthrust nappe
spellingShingle Lei Zhao
Zhidan Chen
Lei Xie
Zhihui Zhu
Wenbin Xu
Coseismic deformation and slip model of the 2024 MW7.0 Wushi earthquake obtained from InSAR observation
地球与行星物理论评
wushi earthquake
coseismic deformation
coseismic slip distribution
thrust nappe
title Coseismic deformation and slip model of the 2024 MW7.0 Wushi earthquake obtained from InSAR observation
title_full Coseismic deformation and slip model of the 2024 MW7.0 Wushi earthquake obtained from InSAR observation
title_fullStr Coseismic deformation and slip model of the 2024 MW7.0 Wushi earthquake obtained from InSAR observation
title_full_unstemmed Coseismic deformation and slip model of the 2024 MW7.0 Wushi earthquake obtained from InSAR observation
title_short Coseismic deformation and slip model of the 2024 MW7.0 Wushi earthquake obtained from InSAR observation
title_sort coseismic deformation and slip model of the 2024 mw7 0 wushi earthquake obtained from insar observation
topic wushi earthquake
coseismic deformation
coseismic slip distribution
thrust nappe
url https://www.sjdz.org.cn/en/article/doi/10.19975/j.dqyxx.2024-010
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AT leixie coseismicdeformationandslipmodelofthe2024mw70wushiearthquakeobtainedfrominsarobservation
AT zhihuizhu coseismicdeformationandslipmodelofthe2024mw70wushiearthquakeobtainedfrominsarobservation
AT wenbinxu coseismicdeformationandslipmodelofthe2024mw70wushiearthquakeobtainedfrominsarobservation