利用小波分析研究河西地区地壳垂直形变特征

THE VERTICAL CRUST DEFORMATION CHARACTERISTICS IN HEXI AREA BY WAVELET ANALYSIS

利用小波分析对河西地区1971—1979、1979—1983年的地壳垂直形变场进行计算,结果表明:三阶以内的小波分解结果与地质构造走向基本一致,说明河西地区地壳垂直运动的短波主要反应的是断层活动;四阶小波变换结果为地壳垂直形变的低频部分,反映的是大区域地质构造运动所引起的地壳垂直形变。1971—1979年,门源南部的地壳垂直运动相对剧烈,而到了1979—1983年,门源地区地壳垂直运动主要活动区域由门源南部地区转移到门源附近区域,这可能与门源6.4级地震孕育的区域构造活动有关。

we calculated the vertical crust deformation field of Hexi area in 1971 - 1979 and 1979 - 1983 by wavelet analysis, it shows that the wavelet decomposition result within the third order are consistent with the ge- ological structure, which indicates that the shortwave of the vertical crust deformation in Hexi area is mainly the reaction of the faults activity ; the fourth order wavelet decomposition is the low frequency part of the vertical crust deformation, which is the reaction of vertical crust deformation of the large regional tectonic activity. The vertical crust deformation in the south of Menyuan area was relatively intense in 1971 -1979 ,while in 1979 - 1983, the mainly active area of the vertical crust deformation in Menyuan area was transferred from the south to the area near Menyuan, this may be related with the regional tectonic activity of the Menyuan M6.4 earthquake preparation.