Horizontal deformation in South Korea from permanent GPS network data, 2000–2003

Abstract

Analysis of continuous GPS data [2000][2001][2002][2003] at 50 stations of the Korean GPS Network (KGN) suggests that the southern part of the Korean peninsula is tectonically more stable than other regions in the Eastern Asia. The average velocity was ∼1.5 mm/yr and the average overall strain rate was around −0.3 × 10 −9 str/yr. The obtained velocity field indicates the presence of anticlockwise rotation of the whole region with respect to Daejeon station (DAEJ), in the central part of South Korea. It also showed that KM-OB (Kyonggi Massif and the Okchon Basin) and YM-TB (Yeongnam Massif and Taebaeksan Basin) have left-lateral shearing movements. Both movements were confirmed by the deformation analysis of the KGN horizontal velocity field using the infinitesimal plate theory. The results show that South Korea moves toward the WNW direction with a velocity of 0.9 mm/yr with a slow anticlockwise rotation. The strain field in South Korea indicates the existence of both compression and tension. The compression and extension axes have WSW-EWE and NNW-SSE directions, respectively.

Present-day crustal motion in northeast China determined from GPS measurements

“…For most sites, the velocities are relatively small, ranging from 0.1 to 3.5 mm/yr for both the NS and EW components, respectively, thereby reflecting the relatively high stability of northeast China relative to other Chinese regions, such as Tibet, and other countries in East Asia, such as Japan (Kato et al, 1998;Shen et al, 2000;England and Molnar, 2005;Shen et al, 2005). The stability of northeast China is comparable with that South Korea (Hamdy et al, 2005). With the exception of five stations (JB11, E003, E040, JB17, SUIY), all stations show insignificant motion at the 95% confidence level, precluding a clear association of their velocities with the rotation of a separate rigid plate (AMU plate).…”

Vertical velocity from the Korean GPS Network (2000–2003) and its role in the South Korean neo-tectonics

“…4) is perpendicular to the Bongwhajae fault line and shows that the TB stations were uplifted while those of OB subsided. This deformation pattern can be explained by considering the horizontal strain tensor observed during the same period 2000-2003, in OB where the predominant strain was compression and the basin translates toward SW (Hamdy et al, 2005). The second cross section along the northern part of OB (section B-B in Fig.…”

“…On the other hand, the Korean GPS Network (KGN), which consists of 50 permanent GPS stations constructed on geologically stable marks (pillars), only became fully operational in 2000. However, since this time, our knowledge on the crustal deformation in the Korean peninsula and its adjacent areas has been improved (Park et al, 2001;Hamdy et al, 2004a, b;2005). Mäkinen et al (2003) claimed that two leveling surveys taken at a 40-year interval would provide accurate vertical velocities of 0.3 mm/year (by assuming white noise, a precision≥0.8 mm/ √ km, and a distance of 100 km).…”

The foliage effect on the height time series from permanent GPS stations

“…These sites are used for various GPS applications, such as real-time navigation, precise surveying, geodesy, and Earth science studies. Since the average operation period of those stations is about 8 years, the site velocities derived from the continuous GPS measurements are an indispensible geodetic tool for crustal deformation studies of the Korean peninsula and the surrounding area (Hamdy et al, 2005;Jin and Park, 2006). For example, Jin and Park (2006) processed 4 years of data and computed the horizontal velocities of 45 GPS sites in South Korea and found that the GPS-derived seismic moment accumulation rate is significant and consistent with recent historic earthquakes and fault zones in South Korea.…”