Some statistic characteristics of “Underground Hot vortex” in China during 1980–1993 (I)

Using ground temperature data from meteorological stations as well as earthquake, ground tilt and precipitation data, the spatial-temporal distribution of “Underground Hot Vortex” (UHV) in China was analyzed in detail. The results show that concerning an “Underground Hot Vortex” cell, its life-span is 3–8 seasons, 1.5 years on average; the mean horizontal scale is 600 km and its characteristic velocity is about 400 km/a; UHV is likely to appear in some areas where the crustal movement is intense and the absolute value of vertical deformation rate is relatively high; its activity could hardly be detected in the area where the crust is stable and the vertical deformation is weak; most of “Underground Hot Vortex Groups” originate from the edge of Indian Plate, then migrate eastwards with a leaping-frog style. 5–10 years are needed for their arrival in the eastern border of China. Their horizontal migrating velocity is 200–500 km/a which is nearly equal to the characteristic velocity of a single UHV.