scholarly journals Source model for the Mw 6.0 earthquake in Jiashi, China on 19 January 2020 from Sentinel-1A InSAR data

2020 ◽  
Author(s):  
Pengfei Yu ◽  
Xuejun Qiao ◽  
Wei Xiong ◽  
Wei Chen ◽  
Zhaosheng Nie ◽  
...  
Keyword(s):  
Transition Zone ◽  
Strong Earthquake ◽  
Earthquake Swarm ◽  
European Space Agency ◽  
Descent Method ◽  
Steepest Descent Method ◽  
Western China ◽  
Coseismic Deformation ◽  
Coulomb Stress Changes ◽  
Stress Changes

Abstract On January 19, 2020, an Mw 6.0 earthquake occurred in Jiashi, Western China. The epicenter was located at the basin-mountain boundary between the southern Tian Shan and the Tarim Basin. Many strong earthquakes occurred in this region, such as the 1997 Jiashi strong earthquake swarm. In this study, Interferometric Synthetic Aperture Radar (InSAR) was used to obtain the coseismic deformation field from the ascending and descending Sentinel-1A satellite data of the European Space Agency. The results showed that the coseismic deformation was distributed along the Kalpingtag fault and the Ozgertaou fault. The earthquake produced significant deformation over an area of approximately 40 km by 30 km. The long axis of the deformation was near the east-west direction. The maximum and minimal displacements along the line of sight (LOS) were 5.3 cm, 7.2 cm and -4.2 cm, -3 cm for the ascending and descending interferograms, respectively. The slip model inverted by the steepest descent method demonstrated that the rupture process of this earthquake is dominated by a thrust fault. The slips were concentrated in a depth of 3.5 ~ 6.5 km. The maximum slip was 0.29 m. The estimated total seismic moment was 1.728×1018 Nm, corresponding to a magnitude of Mw 6.09. The inversion revealed that the coseismic rupture was located at the transition zone between the shallow high-dip fault and the deep detachment fault. The geometry of the coseismic rupture is direct evidence of the deep attitude of the Kalping fault, indicating the possibility of independent earthquakes at the shallow ramp-to-flat transition zone of an orogenic belt. The coseismic Coulomb stress changes have enhanced the stress on the deep margin of the Jiashi earthquake rupture area, indicating that there is still the possibility of another strong earthquake in this region in the future.

scholarly journals Source model for the Mw 6.0 earthquake in Jiashi, China on 19 January 2020 from Sentinel-1A InSAR data

2020 ◽  
Author(s):  
Pengfei Yu ◽  
Xuejun Qiao ◽  
Wei Xiong ◽  
Wei Chen ◽  
Zhaosheng Nie ◽  
...  
Keyword(s):  
European Space Agency ◽  
Source Model ◽  
Descent Method ◽  
Steepest Descent Method ◽  
Coseismic Deformation ◽  
Seismogenic Fault ◽  
Coulomb Stress Changes ◽  
Rupture Area ◽  
Space Agency ◽  
Stress Changes

Abstract On January 19, 2020, an Mw 6.0 earthquake occurred in Jiashi, Xinjiang Uygur Autonomous Region of China. The epicenter was located at the basin-mountain boundary between the southern Tian Shan and the Tarim Basin. Interferometric Synthetic Aperture Radar (InSAR) is used to obtain the coseismic deformation field from both ascending and descending Sentinel-1A satellite images of the European Space Agency. The results showed that the coseismic deformation is distributed between the Kalping fault and the Ozgertaou fault. The earthquake produced significant deformation over an area of approximately 40 km by 30 km. The maximum and minimal displacements along the line of sight (LOS) are 5.3 cm and -4.2 cm for the ascending interferogram and are 7.2 cm and -3.0 cm for the descending interferogram, respectively. The fault geometry from the Multi peak Particle Swarm Optimization computation indicates that the seismogenic fault is a shallow low-dipping planar fault that is 4.58 km depth underground. The finite slip model inverted by the Steepest Descent Method implies that the rupture is dominated by a thrust fault. The slips are concentrated in a depth of 5 ~ 7 km with a maximum slip of 0.29 m. The estimated total seismic moment is 1.688×1018 Nm, corresponding to a magnitude of Mw 6.1. The seismogenic fault is the Kalping fault which has a listric structure. The coseismic deformation only occurred on the décollement layer and did not involve the ramp segment. The coseismic Coulomb stress changes have enhanced the stress on the deep margin of the Jiashi earthquake rupture area, indicating that there is still the possibility of strong earthquakes in this region in the future.

scholarly journals Source model for the Mw 6.0 earthquake in Jiashi, China on 19 January 2020 from Sentinel-1A InSAR data

2020 ◽  
Author(s):  
Pengfei Yu ◽  
Xuejun Qiao ◽  
Wei Xiong ◽  
Wei Chen ◽  
Zhaosheng Nie ◽  
...  
Keyword(s):  
European Space Agency ◽  
Source Model ◽  
Descent Method ◽  
Steepest Descent Method ◽  
Coseismic Deformation ◽  
Seismogenic Fault ◽  
Coulomb Stress Changes ◽  
Rupture Area ◽  
Space Agency ◽  
Stress Changes

Abstract On January 19, 2020, an Mw 6.0 earthquake occurred in Jiashi, Xinjiang Uygur Autonomous Region of China. The epicenter was located at the basin-mountain boundary between the southern Tian Shan and the Tarim Basin. Interferometric Synthetic Aperture Radar (InSAR) is used to obtain the coseismic deformation field from both ascending and descending Sentinel-1A satellite images of the European Space Agency. The results showed that the coseismic deformation is distributed between the Kalping fault and the Ozgertaou fault. The earthquake produced significant deformation over an area of approximately 40 km by 30 km. The maximum and minimal displacements along the line of sight (LOS) are 5.3 cm and -4.2 cm for the ascending interferogram and are 7.2 cm and -3.0 cm for the descending interferogram, respectively. The fault geometry from the Multi peak Particle Swarm Optimization computation indicates that the seismogenic fault is a shallow low-dipping planar fault that is 4.58 km depth underground. The finite slip model inverted by the Steepest Descent Method implies that the rupture is dominated by a thrust fault. The slips are concentrated in a depth of 5 ~ 7 km with a maximum slip of 0.29 m. The estimated total seismic moment is 1.688×1018 Nm, corresponding to a magnitude of Mw 6.1. The seismogenic fault is the Kalping fault which has a listric structure. The coseismic deformation only occurred on the décollement layer and did not involve the ramp segment. The coseismic Coulomb stress changes have enhanced the stress on the deep margin of the Jiashi earthquake rupture area, indicating that there is still the possibility of strong earthquakes in this region in the future.

scholarly journals Source model for the Mw 6.0 earthquake in Jiashi, China on 19 January 2020 from Sentinel-1A InSAR data

2020 ◽  
Vol 72 (1) ◽  
Author(s):  
Pengfei Yu ◽  
Xuejun Qiao ◽  
Wei Xiong ◽  
Wei Chen ◽  
Zhaosheng Nie ◽  
...  
Keyword(s):  
European Space Agency ◽  
Source Model ◽  
Descent Method ◽  
Steepest Descent Method ◽  
Coseismic Deformation ◽  
Seismogenic Fault ◽  
Coulomb Stress Changes ◽  
Rupture Area ◽  
Space Agency ◽  
Stress Changes

Abstract On January 19, 2020, an Mw 6.0 earthquake occurred in Jiashi, Xinjiang Uygur Autonomous Region of China. The epicenter was located at the basin-mountain boundary between the southern Tian Shan and the Tarim Basin. Interferometric Synthetic Aperture Radar (InSAR) is used to obtain the coseismic deformation field from both ascending and descending Sentinel-1A satellite images of the European Space Agency. The results showed that the coseismic deformation is distributed between the Kalping fault and the Ozgertaou fault. The earthquake produced significant deformation over an area of approximately 40 km by 30 km. The maximum and minimal displacements along the line of sight (LOS) are 5.3 cm and − 4.2 cm for the ascending interferogram and are 7.2 cm and − 3.0 cm for the descending interferogram, respectively. The fault geometry from the Multi peak Particle Swarm Optimization computation indicates that the seismogenic fault is a shallow low-dipping planar fault that is 4.58 km depth underground. The finite slip model inverted by the Steepest Descent Method implies that the rupture is dominated by a thrust fault. The slips are concentrated in a depth of 5–7 km with a maximum slip of 0.29 m. The estimated total seismic moment is 1.688 × 1018 Nm, corresponding to a magnitude of Mw 6.1. The seismogenic fault is the Kalping fault which has a listric structure. The coseismic deformation only occurred on the décollement layer and did not involve the ramp segment. The coseismic Coulomb stress changes have enhanced the stress on the deep margin of the Jiashi earthquake rupture area, indicating that there is still the possibility of strong earthquakes in this region in the future.

Multifault complex rupture and afterslip associated with the 2018 Mw 6.4 Hualien earthquake in northeastern Taiwan

2020 ◽  
Vol 224 (1) ◽  
pp. 416-434
Author(s):  
Dezheng Zhao ◽  
Chunyan Qu ◽  
Xinjian Shan ◽  
Roland Bürgmann ◽  
Wenyu Gong ◽  
...  
Keyword(s):  
Main Shock ◽  
Near Field ◽  
Active Faults ◽  
Fault Model ◽  
Body Waves ◽  
Coseismic Deformation ◽  
Coseismic Slip ◽  
Coulomb Stress Changes ◽  
Seismic Displacement ◽  
Stress Changes

SUMMARY We investigate the coseismic and post-seismic deformation due to the 6 February 2018 Mw 6.4 Hualien earthquake to gain improved insights into the fault geometries and complex regional tectonics in this structural transition zone. We generate coseismic deformation fields using ascending and descending Sentinel-1A/B InSAR data and GPS data. Analysis of the aftershocks and InSAR measurements reveal complex multifault rupture during this event. We compare two fault model joint inversions of SAR, GPS and teleseismic body waves data to illuminate the involved seismogenic faults, coseismic slip distributions and rupture processes. Our preferred fault model suggests that both well-known active faults, the dominantly left-lateral Milun and Lingding faults, and previously unrecognized oblique-reverse west-dipping and north-dipping detachment faults, ruptured during this event. The maximum slip of ∼1.6 m occurred on the Milun fault at a depth of ∼2–5 km. We compute post-seismic displacement time series using the persistent scatterer method. The post-seismic range-change fields reveal large surface displacements mainly in the near-field of the Milun fault. Kinematic inversions constrained by cumulative InSAR displacements along two tracks indicate that the afterslip occurred on the Milun and Lingding faults and the west-dipping fault just to the east. The maximum cumulative afterslip of 0.4–0.6 m occurred along the Milun fault within ∼7 months of the main shock. The main shock-induced static Coulomb stress changes may have played an important role in driving the afterslip adjacent to coseismic high-slip zones on the Milun, Lingding and west-dipping faults.

Analysis on the master event method and precise location of 1997 Jiashi strong earthquake swarm in western China

1999 ◽  
Vol 12 (3) ◽  
pp. 285-291 ◽  
Author(s):  
Shi-Yong Zhou ◽  
Zhong-Huai Xu ◽  
Jing Han ◽  
Hong-Xin Xu ◽  
Nuernisha
Keyword(s):  
Strong Earthquake ◽  
Earthquake Swarm ◽  
Western China ◽  
Precise Location ◽  
Jiashi Strong Earthquake Swarm ◽  
Master Event

scholarly journals Rupture Kinematics and Coseismic Slip Model of the 2021 Mw 7.3 Maduo (China) Earthquake: Implications for the Seismic Hazard of the Kunlun Fault

2021 ◽  
Vol 13 (16) ◽  
pp. 3327
Author(s):  
Han Chen ◽  
Chunyan Qu ◽  
Dezheng Zhao ◽  
Chao Ma ◽  
Xinjian Shan
Keyword(s):  
Three Dimensional ◽  
Surface Displacement ◽  
Horizontal Displacement ◽  
Descent Method ◽  
Steepest Descent Method ◽  
Coseismic Deformation ◽  
Slip Model ◽  
Displacement Fields ◽  
Coseismic Slip ◽  
The North

The 21 May 2021 Maduo earthquake was the largest event to occur on a secondary fault in the interior of the active Bayanhar block on the north-central Tibetan plateau in the last twenty years. A detailed kinematic study of the Maduo earthquake helps us to better understand the seismogenic environments of the secondary faults within the block, and its relationship with the block-bounding faults. In this study, firstly, SAR images are used to obtain the coseismic deformation fields. Secondly, we use a strain model-based method and steepest descent method (SDM) to resolve the three-dimensional displacement components and to invert the coseismic slip distribution constrained by coseismic displacement fields, respectively. The three-dimensional displacement fields reveal a dominant left-lateral strike-slip motion, local horizontal displacement variations and widely distributed near-fault subsidence/uplift deformation. We prefer a five-segment fault slip model, with well constrained fault geometry featuring different dip angles and striking, constrained by InSAR observations. The peak coseismic slip is estimated to be ~5 m near longitude 98.9°E at a depth of ~4–7 km. Overall, the distribution of the coseismic slip on the fault is highly correlated to the measured surface displacement offsets along the entire rupture. We observe the moderate shallow slip deficit and limited afterslip deformation following the Maduo earthquake, it may indicate the effects of off-fault deformation during the earthquake and stable interseismic creep on the fault. The occurrence of the Maduo earthquake on a subsidiary fault updates the importance and the traditional estimate of the seismic hazards for the Kunlun fault.

Solution of inverse coefficient problem for fractional anomalous diffusion equation

2012 ◽  
Vol 9 (2) ◽  
pp. 65-70
Author(s):  
E.V. Karachurina ◽  
S.Yu. Lukashchuk
Keyword(s):  
Anomalous Diffusion ◽  
Fractional Derivatives ◽  
Descent Method ◽  
Extremum Problem ◽  
Steepest Descent Method ◽  
Coefficient Problem ◽  
Caputo Fractional Derivatives ◽  
Inverse Coefficient Problem ◽  
Residual Functional ◽  
Inverse Coefficient

An inverse coefficient problem is considered for time-fractional anomalous diffusion equations with the Riemann-Liouville and Caputo fractional derivatives. A numerical algorithm is proposed for identification of anomalous diffusivity which is considered as a function of concentration. The algorithm is based on transformation of inverse coefficient problem to extremum problem for the residual functional. The steepest descent method is used for numerical solving of this extremum problem. Necessary expressions for calculating gradient of residual functional are presented. The efficiency of the proposed algorithm is illustrated by several test examples.

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