Estimation of near-fault strong ground motion and intensity distribution of the 2014 Yutian, Xinjiang, M_S7.3 earthquake

The February 12, 2014, M_S 7.3, Yutian earthquake of Xinjing Uygur Autonomous Region, China, occurred as a result of shallow strike-slip faulting in the tectonically complex region of the northern Tibetan Plateau, with focal depth of 17 km. This earthquake occurred several hundred kilometers north of the convergent India-Eurasia Plate boundary. The location of Yutian earthquake is 110 km north of Yutian County, Hetian region. The maximum intensity is up to Ⅸ in the near-fault field shown in the ShakeMap from the China Earthquake Administration (CEA), which is different from the result from USGS. In this study, we analyzed the source parameters and studied the effect of slip distribution on the fault plane. One finite fault source model was constructed and the strong ground motions, including acceleration and velocity, were calculated. Based on the simulation of the near-fault strong ground motion, we described the intensity distribution of the Yutian earthquake. The maximum simulated intensity, Ⅸ, is consistent with the results from the CEA, but higher than that from USGS (Ⅶ—Ⅷ). In fact, the numerical modeling developed in this study has great application in the strong ground motion prediction and intensity estimation for the earthquake rescue.