川滇地区2010～2013年重力变化及重力网的地震监测能力

研究了当前川滇地区重力网的分形特征,发现其分形维数为1.43~1.62,对应格网距为30~60km,具备了监测Ms5.0级以上地震的能力。选择20′(约37km)的格网间距,对研究区域内2010~2013年的重力变化数据进行格网化,并分析重力变化与地震的关系。虽然经历了芦山Ms7.0级地震的能量释放,但是龙门山断裂带西南段与鲜水河断裂带东南段交叉地带仍然存在较强重力变化,对该区域的震情需继续加强监测。

The Gravity Change over Sichuan-Yunnan Region in 2010-2013 and the Earthquake Monitoring Ability of the Gravimetric Network

In this paper, the fractal characteristics of the gravity network in the Sichuan-Yunnan region are studied. The results show that the fractal dimension is 1.43-1.62, which means that the grid spacing of the gravity network is 30-60 km. The network has the capacity to monitor earthquakes of magnitudes larger than Ms5.0. According to the fractal characteristics of the gravity network, and combined with a calculation test, we selected 20’ (about 37 km) grid spacing to grid the gravity change data from 2010 to 2013 in the studied area. The relationship between gravity change and earthquakes is analyzed in detail. The interannual and cumulative gravity changes show that, even after the energy release of the Lushan Ms7.0 earthquake, the gravity is changing dramatically in the southwest of the Longmenshan fault zone and southeast of the Xianshuihe fault zone. The earthquake situation needs to be monitored continually.