苍梧M_S5.4地震和呼图壁M_S6.2地震震前重力非潮汐变化特征

分别对苍梧M_S5.4地震震前的梧州台和呼图壁M_S6.2地震震前的库尔勒台连续重力观测数据进行分析研究。结果表明,2次地震前梧州台和库尔勒台分别观测到10个月和7个月左右的重力非潮汐持续性上升变化,月均变化速度分别为5.0μGal/月和5.1μGal/月,累计变化分别约为50μGal和35μGal。经现场核实和理论计算排除环境干扰影响,认为2次地震震前数月的重力非潮汐持续上升变化与孕震过程有关,可为构建连续重力观测地震预测指标体系提供重要参考。

Gravity Non-Tidal Variation Characters before the Cangwu MS5.4 and Hutubi MS6.2 Earthquakes

Continuous gravitational observation data before the Cangwu MS5.4 earthquake of Wuzhou station are analyzed and studied, as well as data before the Hutubi MS6.2 earthquake of Korla station. Ten months’ non-tidal persistent gravity increases at about 5.0 μGal per month are observed at Wuzhou station before Cangwu earthquake and 7 months non-tidal persistent gravity increases at about 5.1 μGal per month are observed at Korla station before the Hububi earthquake. The cumulative variation amplitudes are about 50 μGal and 35 μGal respectively. Environmental interference is eliminated through site verification and theoretical analysis. It is believed that the increase in gravitational non-tidal persistence over several months before the two earthquakes may be related to the seismogenic process. The results of this study can provide an important reference for the construction of continuous gravitational observation earthquake prediction index system.