SURFACE DEFORMATIONS IN SAKHALIN FROM GPS DATA

• Main Authors: M. Kasahara, H. Takahashi
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Sakhalin
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.559.1120; http://kiska.giseis.alaska.edu/kasp/kasp04/abstracts/vasilenko.pdf

In the framework of global plate tectonics, a system of major north-south trending faults in Sakhalin is regarded as the Eurasia- North America tectonic plate boundary [1]. According to continuous GPS measurements performed since 1995 at reference stations in the north, middle, and south of the island, Sakhalin moves at a speed of 3 – 4 mm/yr to the west relative to Eurasia and at a speed of 3 – 5 mm/yr to the east relative to North America [2]. The sense of motion agrees with convergence of these plates at Sakhalin and the velocity is about 50 –100 % of the velocity of convergence [3]. Survey-mode GPS observations carried out in 2000 and 2002 at six stations along a profile traversing the island at 50ºN showed that current horizontal deformation in middle Sakhalin combines compression and right-lateral strike slip. The rate of total deformation is 3 – 4 mm/yr, or about half of the convergence rate of the Eurasian and the North American plates in this region [2]. Horizontal GPS velocities at all survey-mode stations in south Sakhalin reoccupied in 1999, 2002, and 2003 are shown in Figure 1. A predominant mode of deformation in this part of the island is the east-west compression at ~ 7 mm/yr (velocities of stations not observed in 1999