断裂区带变形分析方法及应用

Analysis Method of the Crustal Deformation on Fault Zone and Its Application

摘要:

应用GPS观测技术专门研究活动断裂区带的地壳形变及其服务于地震预测的数据处理方法目前还不够完善与充分。本文针对这一问题并结合实际的需求，从场的角度提出了适合于断裂区带活动特征分析的数据处理方法，并以川滇菱形块体东边界带为例，依据1999—2004年的GPS资料对其进行了简要分析。结果表明：①经过这种处理与描述可使人们从多角度更清楚全面地了解断裂及两侧的相对活动，及在空间上的演化特征；②走滑运动等值线显示川滇菱形块体东边界两侧相对活动量最大达15mm／a，分布宽度约400km，然而活动量的2／3只分布在断层两侧近100km的范围内，清晰而定量地显现了高剪切应变的积累与存在的空间；③走滑运动梯度显示川滇形块体东边界带南段变形大于北段；④张压性运动结果显示断裂两侧没有明显的差异变化。

Abstract:

The research on crustal deformation especially in active fault zone using GPS technique and the related data processing method for earthquake prediction are now not perfect and enough. Aimed at this problem and for actual work requirement, the data processing method for the chara-cteristic analysis of crustal deformation in fault zone is suggested from field view in the paper. Based on the GPS data from Sichuan - Yunnan region in 1999 - 2004, the crustal movement characters in eastern boundary fault zone of Sichuan - Yunnan block are analyzed by using this method. The results show as follows ： （ 1 ） The rela- tive movement and spatial variation in both sides of the fault zone can be shown clearly in different view angles by this data processing method. （ 2 ） The deformation width on both sides of the fault zone is about 400 km with the maximum movement value of 15 mm/a. However, 2/3 of the movement distribute in a belt area about 100 km width along the faults. This clearly shows the distribution of slip movement and shearing strain accumulation from the motion isogram. （3） The deformation on southern part is more than that on northern part of Eastern boundary zone of Sichuan - Yunnan Block showed by the gradient varia- tion map of slip movement. （4 ） In perpendicular direction to the fault there is not clearly different de- formation between two sides of the zone.