【摘要】 在经典的非震形变位错模型中,地壳形变被认为是活动块体刚性运动和上部断层锁定影响的叠加,本文对此模型进行了改进:（1）用活动块体整体运动和内部线性应变、旋转的贡献代替活动块体刚性运动的贡献;（2）用分层介质地壳模型代替半无限介质模型计算断层锁定的影响.利用改进后的非震形变位错模型,拟合了台湾地区1990～1995年间GPS观测资料.结果显示,在东部海岸山脉区,约有30 mm·a^-1的汇聚率被奇美断层消耗掉,运动速度从奇美断层向北迅速衰减.在西部平原地区,南部断层是岛内锁定最为强烈的断层,该地区相应的也是史上灾害性地震多发的地区.根据反演结果计算出的应变率与旋转率分布与前人结果在大部分地区一致,主应变率场显示台湾大部分地区存在近NW-SE方向的主压应变,主压应变方向呈扇形分布.旋转率场显示台湾东部和南部地区存在着逆时针旋转率,而西部和北部地区则为顺时针旋转率.更多还原

【Abstract】 In previous dislocation model,the aseismic crustal deformation is regarded as the sum of the rigid block motion and the effect of the locked fault.We modify the dislocation model in two aspects.Firstly,the block motion is assumed to be the sum of rotation and linear strain rather than the rigid motion.Secondly,the elastic layered-earth model rather than the homogenous half-space model is applied to calculate the effect of the locked part.The 1990～1995 Global Position System （GPS） velocity data of the Taiwan area are used in our dislocation model. Our simulation shows that in eastern Coastal Range,the velocity decreases northward rapidly from Chimei Fault,which may result from the high crustal compressive rate of about 30 mm·a^-1 at Chimei Fault.In western Taiwan,the most strongly locked faults appear in the southern Coastal Plain where many disaster earthquakes occur frequently.The calculated strain and rotation rates consist with previous results in most areas.The strain rate field reveals the nearly NW SE compression in most parts of Taiwan with a fan-shaped distribution.The rotation rate field reveals anticlockwise rotation in eastern and southern Taiwan while clockwise rotation in western and northern Taiwan,generally.更多还原