Viscoelastic behavior of the crust around the Longmenshan Thrust Belt inferred from post-seismic deformation of the 2013 Lushan earthquake, China. (15th April 2019)

• Record Type: Journal Article
• Authors: Wang, Qixin; Xu, Xiwei; Shyu, J. Bruce H.; Jiang, Zaisen; Liu, Shaozhuo; Wu, Yanqiang; Liu, Xiaoxia; Xiong, Xiaohui; Tan, Xibin; Lu, Renqi; Wei, Wenxin; Zou, Zhenyu
• Is Part Of: Journal of Asian earth sciences. Volume 173(2019)
• Page Start: 386
• Page End: 396
• Publication Date: 2019-04-15
• Subjects: Lushan earthquake -- Crustal viscosity -- continuous GPS measurements -- Longmenshan Thrust Belt -- Tibetan Plateau; Earth sciences -- Asia -- Periodicals; Sciences de la terre -- Asie -- Périodiques; Earth sciences; Asia; Periodicals; 555.05
• DOI: 10.1016/j.jseaes.2019.02.001
• Languages: English
• ISSNs: 1367-9120

Abstract

Graphical abstract: Highlights: The viscosities of the middle-lower crust of the Longmenshan Thrust Belt (LTB), China, are studied. Rheological properties are not the main controlling factor on fault activity of the LTB. The lower fault activity along the southern LTB may be due to a greater number of structures. Abstract: Seven continuous GPS stations are located on the hanging wall of the Longmenshan Thrust Belt, and post-seismic deformation data of the 2013 Lushan earthquake have been recorded for nearly four years following the earthquake. We transform the data from a global reference frame to the South China Block reference frame, and then, the secular motion and post-seismic deformation of the Wenchuan earthquake are excluded using an exponential fit model. Based on our results, the viscosities of the low velocity zone at a depth of ∼25 km and of the middle and lower crust around the Longmenshan Thrust Belt are obtained as 2.75 × 10 17 P a · s and 2.56 × 10 18 P a · s, respectively. The post-seismic rebound, which was observed near the Lushan epicenter, may represent the occurrence of overslip during the earthquake. The more complex structural style may have produced weaker fault activity along the southern segment of the Longmenshan Thrust Belt than along its middle and northern segments.