THE DISTRIBUTION CHARACTERISTICS OF DEFORMATION FIELD CAUSED BY THREE GREAT EARTHQUAKES IN THE QINGHAI-TIBET PLATEAU AND ITS VICINITY SINCE 2001

Based on a viscous-elastic crustal model with constraint conditions from GPS and seismic dislocation data and adopting the finite element method, we analyzed the crustal deformation characteristics caused by 2001 Kunlun Mountain M S 8.1, 2008 Wenchuan M S 8.0 and 2015 Nepal M S 8.1 earthquakes, obtained the displacement and deformation field. These earthquakes have occurred in the north, east, and south margins of the Tibetan Plateau respectively. Our primary results suggest obvious differences in deformation regimes, seismogenic fault geometry and source parameters, as well as crustal deformation patters despite the substantially similar magnitudes. These differences caused by seismogenic fault nature and subsurface structures are mainly manifested by different scopes of deformed regions and different strain amplitudes. Through these simulation results, we can detect more about the distribution characteristics of stress loading and unloading area caused by large earthquakes. Moreover, it plays an important role in forecasting the earthquake possibility of seismogenic region.