Using geodetic data to calculate stress changes on faults in the Tibetan Plateau caused by the 2015 M(w)7.8 Nepal earthquake

摘要

The 2015 M(w)7.8 Nepal earthquake occurred on the segment of the main Himalayan thrust fault between the Indian and Eurasian plates, and caused serious casualties. This earthquake may produce a profound impact on the evolution of the Tibetan "Plateau and have brought a stress loading to faults within the plateau. In this paper, a high-resolution slip distribution of the 2015 Nepal earthquake is inverted from the InSAR and GPS data in the near field, and is used to compute the evolution of the cumulative Coulomb stress changes on faults in the earthquake-prone zone in the Tibetan Plateau. In the given reasonable parameters, the calculated co- and post-seismic stress changes on faults do not exceed 1.0 kPa at the north of latitude 32 degrees in the Tibetan Plateau. The largest positive stress changes occur on the South Tibet Detachment fault, and the magnitudes are much less than 100 kPa. The estimated seismicity rate change on the segment of the South Tibet Detachment fault can be up to a level of two hundred thousandths. This indicates that there is a high hazard of earthquake triggering in the South Tibet Detachment fault and its adjacent regions. In the northern and eastern Tibetan Plateau, the estimated seismicity rate changes are lower than a level of one thousandth. However, some faults with a relative high background seismicity rate, such as the Xianshuihe and Longmenshan faults, may have a high hazard of earthquake triggering in the future. (C) 2016 The Author(s). Published by Elsevier Ltd.