辽宁地区地壳垂直形变演化特征

EVOLUTIONAL CHARACTERISTICS OF VERTICAL CRUSTAL DEFORMATION IN LIAONING AREA

利用辽宁地区多期复测的水准资料,得到1959—1979年、1979—1997年、1997—2010年和1959—2010年多个时间段的垂直形变速率。在此基础上研究了辽宁地区50年的地壳垂直形变演化和构造活动性,以及垂直形变场与地震活动的相关性。结果表明:1959—1979年的垂直形变速率差异变化量最大,地壳活动性较强烈,该时间段内发生了海城7.3级地震。1979—1997年和1997—2010年两个时间段垂直形变速率差异变化量减小,地壳活动性减弱,同时期本区无大震发生。垂直形变速率变化显示出,辽宁地区地壳活动以北北东向和北西-北西西向构造为主,不同时期的垂直形变分别受它们控制。

The repetitive leveling data in Liaoning area was sorted out to obtain the vertical deformation rate during 1959-1979, 1979-1997 and 1997-2010. On the basis of the results,the author studied the evolution of vertical crustal deformation, tectonic activity of Liaoning area in 50 years, and the correlation of vertical deforma- tion field with seismic activities. The results show that during 1959 to 1979, the differential change of the vertical deformation rate is the biggest, that reflects the crustal activity is intense, and a Ms7.3 earthquake occurred in Haicheng in this period. During 1979 to 1997 and 1997 to 2010, the differential change of the vertical deformation rate decreased, the crustal activity weakened, and there was no big earthquake occurred in this period. In the peri- od, the differential change of the vertical deformation rate shows that the predominant direction of crust activity of Liaoning area was NNE and NW-NWW, and the vertical deformation in different periods was respectively under the control along these directions.