Tectonic activities and deformation in South Korea constrained by GPS observations

摘要

High precision GPS observations provide crucial insights into understanding the pattern and physical process of tectonic activities. In this paper, GPS data for the period from March 2000 to February 2004 were analyzed to quantitatively investigate the crustal deformation patterns and distributions in the southern Korean Peninsula. The high maximum shear strain rates are concentrated in the middle part of South Korea, which remarkably agrees with the shear trends in the Okcheon Belt and the Honam Shear Zone (HSZ) with a direction NE-SW. In addition, South Korea is dominated by both ENE-WSW compression and NNW-SSE extension, which is nearly consistent t with earthquake focal mechanism solution (M_w ≥ 4.0, 1936-2004), indicating that the seismicity can be used to improve GPS-derived deformation style and orientation. Furthermore, it reflects that the occurrence of shallow earthquakes in South Korea is closely related with the horizontal strain.