Coulomb Stress Change and Evolution Induced by the 2008 Wenchuan Earthquake and its Delayed Triggering of the 2013 Mw 6.6 Lushan Earthquake

2014 ◽  
Vol 85 (1) ◽  
pp. 52-59 ◽  
Author(s):  
Y. Wang ◽  
F. Wang ◽  
M. Wang ◽  
Z.-K. Shen ◽  
Y. Wan
Keyword(s):  
Wenchuan Earthquake ◽  
Lushan Earthquake ◽  
Stress Change ◽  
Coulomb Stress ◽  
Coulomb Stress Change ◽  
2008 Wenchuan Earthquake ◽  
The 2008 Wenchuan Earthquake

scholarly journals A possible precursor prior to the Lushan earthquake from GPS observations in the southern Longmenshan

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Qixin Wang ◽  
Xiwei Xu ◽  
Zaisen Jiang ◽  
John Suppe
Keyword(s):  
Wenchuan Earthquake ◽  
Epicentral Distance ◽  
Elastic Strain Energy ◽  
Lushan Earthquake ◽  
Dislocation Model ◽  
Seismogenic Fault ◽  
2008 Wenchuan Earthquake ◽  
The 2008 Wenchuan Earthquake ◽  
Longmenshan Thrust Belt ◽  
Preseismic Deformation

AbstractGlobal Positioning System (GPS) stations installed in and around the epicenter of the Lushan earthquake (Mw 6.7), which occurred almost 5 years after the 2008 Wenchuan earthquake, recorded preseismic deformation corresponding to the Lushan earthquake within the southern Longmenshan thrust belt. A half-space dislocation model is used to simulate the theoretical values of the postseismic displacements caused by the 2008 Wenchuan earthquake, and after transforming the reference frame and filtering the GPS displacement time series, the theoretical and observed GPS values are compared to identify the geodetic anomaly preceding the Lushan earthquake. The abnormal extent of this geodetic anomaly decreases with increasing epicentral distance for each GPS site. This geodetic signal reflects preslip along a locked section of the 2013 seismogenic fault, which caused the accumulation of elastic strain energy until the faulting strength was overcome, thereby generating the Lushan earthquake. Hence, this anomaly might be used as an observable and identifiable precursor to forecast an impending earthquake within a period of less than two and half years before its occurrence.

Eikonal Equation-Based Seismic Tomography of the Source Areas of the 2008 Mw 7.9 Wenchuan Earthquake and the 2013 Mw 6.6 Lushan Earthquake

2020 ◽  
Vol 110 (2) ◽  
pp. 886-897
Author(s):  
Jun Li ◽  
Hui Li ◽  
Hui Chen ◽  
Jinrong Su ◽  
Yongsheng Liu ◽  
...  
Keyword(s):  
Wenchuan Earthquake ◽  
High Velocity ◽  
Lushan Earthquake ◽  
Low Velocity ◽  
Longmenshan Fault Zone ◽  
2008 Wenchuan Earthquake ◽  
Velocity Anomaly ◽  
The 2008 Wenchuan Earthquake ◽  
Longmenshan Fault ◽  
2013 Lushan Earthquake

ABSTRACT We use the eikonal equation-based seismic travel-time tomography method to image the source areas of the 2008 Wenchuan earthquake and the 2013 Lushan earthquake in the Longmenshan fault zone. High-resolution VP and VS models are obtained by inverting 75,686 P-wave and 74,552 S-wave travel times of local earthquakes during the period from 2009 to 2018. The tomographic models reveal strong crustal velocity heterogeneities in the study area. A significant velocity contrast exists across the Longmenshan fault zone: The western Songpan–Ganzi block is a high-velocity body, whereas the eastern Sichuan basin is a low-velocity anomaly. The hypocenter of the 2008 Wenchuan earthquake is between a high-velocity and a low-velocity anomaly. Beneath the Wenchuan mainshock, there is a significant low-velocity structure in the lower crust. The 2013 Lushan earthquake occurred in rocks associated with a high-velocity anomaly. A distinct low-velocity zone with low seismicity is imaged between the 2008 Wenchuan earthquake and the 2013 Lushan earthquake, where the crustal ductile deformation is likely to occur. The Baoxing complex to the northwest of the Lushan hypocenter exhibits as a high-velocity anomaly, which may be a carrier of stress accumulation and more prone to seismic activities in the future.

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