2006年乌苏MS5.1地震前后北天山地倾斜资料异常分析

Analysis on Anomalies of Ground Tilts Data in Northern Tianshan Area before and after Wusu Ms5.1 Earthquake in 2006

摘要:

分析了2006年11月23日新疆乌苏MS5.1地震前后距震中250 km范围内的北天山地倾斜观测资料。认为2005年初以来绝大多数测项存在明显的准同步性趋势异常,以趋势性加速E倾、N倾为主,地震发生在大多数异常结束并出现返向加速变化之后,少数在趋势性E倾、N倾过程中;空间上愈接近震中,异常开始时间愈早,异常测项也较为集中。与以往震例比较该次地震前中短期和短临异常不明显,震后绝大多数趋势异常仍在持续,可能表明北天山地区依然存在发生中强地震的背景。

Abstract:

The observational data of ground tilts in the range of 250 km around the epicenter, before and after Wusu Ms5. 1 Earthquake on November 23,2006 are analyzed. The result shows, since the beginning of 2005, there were evident quasi-synchronous trend anomalies in most ground tilts observational data. The main abnormal characteristics were trend E and N directions inclination quickly, and most earthquakes occurred after the anomalies ending and speeding up in the opposition, only minority of them did in the process of anomalies. Analyzing spatio-temporal distribution of the anomalies, the nearer to the epicenter, the earlier the anomalies began, and the more the number of abnormal items were, too. Comparing with previous earthquake cases, the mid-short and impeding anomalies are not obvious and most trend anomalies are still standing after the earthquake, which indicates occurring of Wusu Ms5. 1 earthquake doesn＇t relieve the earthquake risk in northern Tianshan Mountain area.