STUDY ON THE REGIONAL DEFORMATION FIELD AND STRONG EARTHQUAKE RISK OF BEIJING AREA IN THE NEAR FUTURE

the background value of regional deformation field observed with leveling and GPS as well as its relationship with the faults deformation value given by fixed observation stations from 1998 to 2000 in Beijing area are analyzed.The study indicates;(1)The vertical deformation rates and its gradient in this area are lower than the normal value of North China area and the corresponding value before some strong earthquakes;(2)The horizontal deformation rates given by GPS measurements are also at a lower level in this area;(3)The fault deformation rates (vertical and horizontal)at fixed observation sites are equal to the regional background value;(4)Based on the state of large-scale deformation field and the level of fault deformation anomalies mentioned above, there will be no stronger earthquake in the area in future 1-3 years.