Active tectonic deformation around the Tarim Basin inferred from dense GPS measurements

Abstract

The surrounding area of the Tarim Basin is featured by active tectonic deformation and intense seismic activity. The study of the crustal deformation characteristics of this area will help revealing the role of the Tarim Basin in the crustal evolution. In order to accurately obtain the deformation characteristics of this area, we firstly obtained the highly detailed and accurate three-dimensional (3D) crustal deformation velocities of the Tarim Basin and its surrounding areas through high-precision processing of existing Global Positioning System (GPS) data. Thereafter, the slip rate and strain rate fields of the main faults in the region were calculated based on the updated velocity results. The strain rate of the Altyn Tagh fault is dominated by shear strain and the strike slip rate is 8–10 mm/yr. The strain rate between the Tien Shan and Tarim Basin is dominated by extrusion strain, and the extrusion rate is 4–6 mm/yr. In addition to the large shear strain, there is also a certain tensile strain in the Tibetan Plateau. Geodetic results show that the main driving force for the deformation of the Tien Shan is the northward thrust of the Tarim Basin. The relative movement mode between the Tarim Basin and Tibetan Plateau mainly comprises the strike slip movement along the strike direction of the Altyn Tagh fault, with a small extrusion deformation. Therefore, the Tarim Basin has little influence on the north–south shortening deformation of the Tibetan Plateau.