Distribution characteristic of strain rate field in Tianshan region by least squares collocation

This paper obtains the spatial distribution characteristics of strain rate field at the Tianshan region based on the available GPS velocity field by using the least squares collocations method in sphere surface. The maximum principal compressive strain result shows that strong earthquakes often occur at the zones where principal compressive strain always has been rapidly alternating from high value to low value. The maximum strain rate is located in the junction of southwestern Tianshan, Pamir arc and northwestern Tarim basin where several M7.0—8.0 earthquakes occurred in the past century. The surface dilation rate of the Tianshan region reveals that the Tianshan as a whole is uplifting due to compressive deformation.