Project plan and research progress on geodynamic models of earthquakes and strong seismic hazards in boundary zone of the Ordos active block

The Ordos active block and its surrounding areas are ideal to examine and develop the active block theory on geodynamics and seismic hazards. In recent years, research on geodynamics of the Tibetan Plateau has become a new hotspot in geoscience both at home and abroad. This project will target on the Ordos active block and its boundary belts （a key seismic hazard area in continental China）, which located on the east end of the Silk Road economic belt, establish the three-dimensional structural models of deep and shallow structures, build the regional geodynamic models of strong earthquake preparation processes inside the plate, improve the active block theory of strong continental earthquake preparation and occurrence, to develop a time-dependent strong earthquake prediction model with physical significance, and propose a technical regulation of earthquake prediction. The active block theory, which has been proposed by Chinese scientists at the end of 20th century, has suggested that the continental strong earthquakes mainly occurred on the active block. The theory provides important guidance for predicting the strong-earthquake-occurring locations in China. However, further work is necessary to apply it into practice, including research on how the block movement and structural deformation of active blocks control the preparation and occurrence of strong earthquakes on the boundary zones. Therefore, we focus on the Ordos active block to carry out the following research contents, including the behaviors of fault activity and strong earthquake recurrence of the block boundary zones, the 3D crustal movement and strain partitioning of the Ordos block and its surrounding areas, the structural coupling between deep and shallow structures of the Ordos block and its boundary zone, and the perfection of active block theory and research on the strong earthquake hazard on the boundary zones. In the last two years after starting the project, some preliminary results have been achieved. We have built a model to study the strong earthquake recurrence behaviors, obtained different patterns of 3D crustal movements in the Ordos block and its surrounding areas, built a coupling model between deep and shallows structure in the key regions, and conducted research on strong earthquakes hazard.