用离散点观测资料解算走滑断层应变积累时的失真现象及其原因

摘要

利用GPS等离散点观测资料解算因走滑断层闭锁所产生的应变积累时,在断层附近会产生不可忽略的应变失真现象.失真应变的空间分布特征不会随着测站间距的变化而变化,但其量值随测站间距缩小而减小,因此减小测站间距(即加密观测)一定程度上能够削弱失真应变现象.解算应变场时隐含着地壳介质连续均匀性的弹性假设,但实际的地表形变场并不符合这一假设条件,这是产生应变失真现象的主要原因.%Using GPS or other discrete measurements to calculate strain accumulation caused by fault coupling on strike slip fault,artificial strain cannot be ignored in the vicinity of the fault.The distribution pattern of artificial strain will not change with the change of station spacing.The size of atificial strain will decreases with the decrease of distance between the stations.To a certain extent,reducing station spacing will weaken artificial strain.The assumption of the crustal deformation field continuity is implied in strain calculation,whereas the actual strain field is not consistent with the assumption of the homogeneity of the crustal medium,which results in artificial strain.