Present-day kinematics and seismic potential of the Ganzi-Yushu fault, eastern Tibetan plateau, constrained from InSAR

Abstract

In recent years, earthquakes have occurred frequently on the southeastern edge of the Tibetan Plateau, and the seismic hazard is high. However, because of the remote location of the Ganzi-Yushu fault zone, no high-resolution geodetic measurements of this region have been made. The radar line-of-sight deformation field of the Ganzi-Yushu fault was obtained using seven-track ascending and descending Sentinel-A/B interferometric synthetic aperture radar (InSAR) data from 2014 to 2020. Using the InSAR and published Global Navigation Satellite System (GNSS) data, we calculated the 3D deformation field in the study area, investigated the segment-specific fault slip rate, and inverted the fault slip distribution pattern using the steepest descent method. We then evaluated the seismic hazard using the strain rate field and slip deficit rate. The main findings of this study include the following. 1) The slip rate of the Ganzi-Yushu fault gradually increases from 2.5 to 6.8 mm/yr from northwest to southeast. 2) A high-resolution strain rate map shows high-value anomalies in the Yushu and Dangjiang areas. 3) Our comprehensive analysis suggests that the seismic hazard of the Dangjiang and Dengke segments with high slip deficits cannot be ignored.

Study of the Interseismic Deformation and Locking Depth along the Xidatan–Dongdatan Segment of the East Kunlun Fault Zone, Northeast Qinghai–Tibet Plateau, Based on Sentinel-1 Interferometry

“…Since the launch of the satellite, Sentinel-1 data have been widely used in the study of coseismic deformation, such as the 2014 Napa California M W 6.1 earthquake [38,44,45], the 2015 Nepal M S 8.1 earthquake [39,46], and the 2017 Jiuzhaigou M S 7.0 earthquake [40,47]. With the accumulation of SAR satellite data over the years and the continuous improvement of InSAR data processing technology, InSAR technology should also obtain an extensive range and high-resolution fault tectonic deformation field (e.g., [19,25,[27][28][29][30]48,49]).…”

Reconstructing the Geometry of the Yushu Fault in the Tibetan Plateau Using TLS, GPR and Trenching

“…On 14 April 2010, a destructive Ms 7.1 earthquake happened on the Yushu fault, causing ~3000 casualties and serious economic losses [34][35][36]. Since this earthquake, many studies have been conducted on the rupture process [37][38][39][40][41], surface fractures [36,[42][43][44][45][46][47], paleoearthquake recurrence [45,48,49], and the slip rate of the Yushu fault [35,50,51], and so on. Although it is undisputed that the Yushu fault has been dominated by a sinistrallateral strike-slip movement since the Quaternary, there are many different views on the kinematics and characteristics in the literature, especially the slip rate.…”

“…Unfortunately, due to complex geological conditions and a severe natural environment with high altitudes and the risk of hypoxia, it was difficult to acquire high-resolution geomorphologic information and subsurface structures in the Yushu area. There had been little work on geomorphic features and shallow geometry of the Yushu fault using unmanned aerial vehicles (UAVs), LiDAR [52] or other geophysical methods [53][54][55]. Hence, high-resolution geomorphologic information and stratigraphic datasets are fundamental for active faults investigation in the Yushu area, as they have great significance for evaluating the probability of future destructive earthquakes and seismic hazards.…”