四川龙门山断层带的GPS测量与2008年汶川地震

GPS MEASUREMENTS AT SICHUAN LONGMENSHAN FAULT AND 2008 WENCHUAN EARTHQUAKE

根据中国大陆地壳运动GPS的观测结果,初步估计了沿四川龙门山断层带西北-东南两侧断层间东南向的聚敛率,并与2008年5月12日发生在四川汶川县的Ms8.0级特大地震触发产生的沿龙门山断层带的水平向破裂位移的相应分布进行了比较,结果证实,如同2004年苏门答腊-安达曼岛地震引起的地壳破裂滑行位移与板块间的聚敛率的关系一样,汶川Ms8.0级地震引起的近300km长的龙门山断层破裂位移分布与断层间的聚敛率大小密切相关。根据在龙门山断裂带沿带区域断层间每年几毫米量级的聚敛率结果和汶川Ms8.0级地震引起的逆冲位移观测结果,可估计得到龙门山断层带断层间聚敛应力的累积时间约为数百年至近千年,这个时间尺度与区域性特大地震发生的时间分布基本吻合。

Based on the GPS measurements of station velocity vector along the Longmenshan fault zone of Sichuan province,China,the convergence rates between both sides of the fault zone with about 300 km long are estimated,and the comparison between the rates mentioned above and the corresponding slip displacements along the fault caused by 2008 Wenchuan earthquake is made. Results indicate that the displacements mentioned above and aftershock distributions along the fault after the main earthquake are closely related...