【摘要】 高精度GPS测量是研究现今地壳运动和地壳形变的重要手段之一。2013年4月20日,龙门山断裂带南段芦山地区(30.3°N,103.0°E)发生了MS7.0级地震。震后的野外考察表明,芦山地震在震中区没有形成具有构造地质意义的地震地表破裂带。文中根据震中附近监测站(BXB:30.48°N,102.71°E和BXN:30.26°N,102.84°E)资料,通过对震前、震后的GPS监测数据反演、分析,推断芦山4·20地震发生机理为逆冲-错动型地震。GPS监测结果显示,震区的同震位移量为:断裂北侧测站BXB即断层西北盘(上盘)东向同震位移量为34.0mm,北向同震位移量为-28.2mm,垂向抬升10.3mm;断裂南侧测站BXN即断层东南盘(下盘)东向同震位移量为-45.5mm,北向同震位移量为-25.9mm,垂向同震位移下沉为67.8mm。芦山4·20地震使得断层南北向缩短3~6mm,水平错动位移78~82mm,断裂垂向错动75~80mm。更多还原

【Abstract】 The high precision GPS measurement is an important method for studying the crustal movement and crustal deformation.On April 20,2013,an earthquake of MS7.0occurred in Lushan(30.3°N,103°E),south of Longmenshan faults.According to the monitoring station(BXB:30.48°N,102.71°E and BXN:30.26°N,102.84°E)data and based on GPS monitoring data inversion and analysis,it is inferred that the 4.20Lushan focal mechanism is a thrust-diastrophism type of earthquake.GPS monitoring results showed the co-seismic displacement as the follows:on the north side of the fault station BXB,the east component of the co-seismic displacement is 34.0mm,the north component of co-seismic displacement is-28.2 mm,and the vertical component of co-seismic displacement is +10.3 mm;on the south side of the fault station BXN,the east component of co-seismic displacement is-45.5 mm,the north component of co-seismic displacement is-25.9mm,and the vertical component of co-seismic displacement is-67.8mm.In the earthquake zone,the length from north to south was shortened by 3-6mm,the horizontal dislocation displacement is 78-82mm,and the vertical dislocation displacement is 75-80mm.更多还原