汶川地震地形形变监测与分析

地形形变监测与分析对于研究汶川地震对震区及青藏板块地形变化的影响有重要意义。通过收集相关监测点的汶川地震前后地形形变数据,采用统一模式进行数据处理,将震前与震后的形变监测成果归算到ITRF2005参考框架和2008.363（2008年5月12日）历元,计算得到震中区域的大地基准造成严重破坏,监测点形变位错,水平位移量达243 cm,沉降量达68 cm,隆起量达36 cm。并对汶川地震地形形变监测进行分析,认为位于“映秀镇—北川—青川”断裂带西侧块体呈现向东南方向移动并呈现隆起趋势;东侧块体向西北方向移动并呈现下沉趋势;北侧块体向东北方向移动,南侧块体向西南北方向移动,块体两侧形成了明显挤压形态。上述研究为进一步揭示汶川地震产生的机理和龙门山断裂带的活动提供了良好基础。

Analysis and Monitoring of Crustal Deformation in Wenchuan Earthquake

Analysis and monitoring of crustal deformation are of significance to study the influence of Wenchuan Earthquake to the topographical change of seismical region and Qinghai-Tibet Plate.Observation data of crustal deformation before and after Wenchuan Earthquake in related monitoring stations were collected.Based on uniform model,the data of monitoring of crustal deformation before and after Wenchuan Earthquake were calculated to ITRF2005 reference frame and 2008.363 epochs（May 12,2008）.The result showed that the geodetic datum of epicenter area was damaged seriously;the deformation of monitoring stations had been deformed and dislocated with horizontal displacement of 243 cm,settlement of 68 cm and uplift amount of 36 cm.In addition,deformation monitoring of Wenchuan Earthquake was discussed.The result showed that the west block of ＂Yingxiuzhen-Beichuan-Qingchuan＂ fault zone had moved to the southeast and had taken on an uplift trend;the east block had moved to the northwest and had taken on a downward trend;the north block had moved to the northeast,the south block had moved to the southwest,both sides of blocks formed a clear extruded shape.The results laid a solid foundation for revealing the mechanism of Wenchuan Earthquake and the movement of Longmen Mountain fault zone.