Present-Day Deformation of the Gyaring Co Fault Zone, Central Qinghai–Tibet Plateau, Determined Using Synthetic Aperture Radar Interferometry

• Main Authors: Yong Zhang, Chuanjin Liu, Wenting Zhang, Fengyun Jiang
• Format: Article
• Language: English
• Published: MDPI AG 2019-05-01
• Series: Remote Sensing
• Subjects: Central Qinghai–Tibet Plateau; Gyaring Co fault; InSAR; strain; slip rate; v-shaped conjugate strike-slip fault
• Online Access: https://www.mdpi.com/2072-4292/11/9/1118

Because of the constant northward movement of the Indian plate and blockage of the Eurasian continent, the Qinghai−Tibet Plateau has been extruded by north−south compressive stresses since its formation. This has caused the plateau to escape eastward to form a large-scale east−west strike-slip fault and a north−south extensional tectonic system. The Karakorum−Jiali fault, a boundary fault between the Qiangtang and Lhasa terranes, plays an important role in the regional tectonic evolution of the Qinghai−Tibet Plateau. The Gyaring Co fault, in the middle of the Karakoram−Jiali fault zone, is a prominent tectonic component. There have been cases of strong earthquakes of magnitude 7 or greater in this fault, providing a strong earthquake occurrence background. However, current seismic activity is weak. Regional geodetic observation stations are sparsely distributed; thus, the slip rate of the Gyaring Co fault remains unknown. Based on interferometric synthetic aperture radar (InSAR) technology, we acquired current high-spatial resolution crustal deformation characteristics of the Gyaring Co fault zone. The InSAR-derived deformation features were highly consistent with Global Positioning System observational results, and the accuracy of the InSAR deformation fields was within 2 mm/y. According to InSAR results, the Gyaring Co fault controlled the regional crustal deformation pattern, and the difference in far-field deformation on both sides of the fault was 3−5 mm/y (parallel to the fault). The inversion results of the back-slip dislocation model indicated that the slip rate of the Gyaring Co fault was 3−6 mm/y, and the locking depth was ~20 km. A number of v-shaped conjugate strike-slip faults, formed along the Bangong−Nujiang suture zone in the central and southern parts of the -Tibet Plateau, played an important role in regional tectonic evolution. V-shaped conjugate shear fault systems include the Gyaring Co and Doma−Nima faults, and the future seismic risk cannot be ignored.