用全球卫星定位系统资探讨地壳变形与地震活动的相关性(III).pdfVIP

利 料 III 劉 利 年利 省 料 量 料 來累 度連 GPS 年來 921 精 GPS 度利度來不 年 度利 年量 料 了理 都 來 類 During the period of 3 years study in this research project, we analyzed the spatial and temporal variations of the crustal deformations before and after major earthquake s using the GPS data from the Permanent Global Positioning System Network set up by the Central Weather Bureau, and some of the related geodetic observations in the last few years. We tried to investigate the relationship between the stress / strain rate with the seismicities. For the 3 year of studies, we process the daily solutions for the TAINET network, then using Kalman filter to combine the daily solutions into the 259 yearly velocity and precise coordinate for each site. One can identifies a site as in the normal situation if the components of its velocity are steady for a period of time, say at least 3 or 4 years. If any site show velocity deviated from the velocity at the normal time this site should be, then we can regard it as abnormal. Unfortunately, the big 921 earthquake came at 1999 before the time we can setup the normal velocity for each site. Most of the efforts must be rebuild up so that we can get the normal velocity for each site. Nevertheless, we can still find many significant crustal deformation patterns which may be related to the possible pre-seismic features, and some unusual co-seismic deformation behavior of the crustal movement.