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

Abstract

GPS measurements carried out between 1997 and 2005 at 37 stations distributed throughout northeast China place indicate the presence of constraints on the present-day crustal motion in this region. Velocity vectors relative to Eurasia are very small, only 1.58 mm/yr on average, indicating that the region is generally stable. With the exception of five stations that show significant motion at the 95% confidence level, the insignificant motion of most stations precludes a clear association of their velocities with the rotation of a separate rigid microplate, suggesting that northeast China belongs to Eurasia plate. The velocities of several stations in the southwestern corner of the studied region consistently point to the southeast. This is most probably a distant effect of the eastward motion of northern Tibet. Small velocities of the stations of around the time of the 1999 M W = 7.1 and 2002 M W = 7.3 deep-focus earthquakes, which occurred in Wangqing county, suggest that these earthquakes did not cause wide-spread deformations to the shallow crust.

Present tectonics of the southeast of Russia as seen from GPS observations

“… Horizontal velocities of the southeast of Russia estimated from GPS observations and calculated by using different AMU/EUR rigid rotation models characterizing the appropriate model groups: (a) Heki et al . 1999 (first group), Prawirodirdjo & Bock 2004 (second group); (b) England & Molnar 2005 and Meng et al . 2006 (third group); (c) Wei & Seno 1998 (fourth group).…”

“…This conclusion is in a quite good agreement with the recent estimates of modern tectonics of Northeast Asia and North China, which are also characterized by small northeast and southeast velocities (England & Molnar 2005; Calais et al . 2006; Meng et al . 2006; Jin et al .…”

“…Nonetheless, we verified how well the obtained velocity field corresponds to the conception of a separate rigid rotation of the AMU microplate with respect to EUR. The velocities of three Chinese GPS sites located near the investigated region were taken from Meng et al . (2006) and transformed into ITRF2008, referred to EUR as described in chapter 2, and were also combined with our GPS velocity field.…”

“…(2006), Calais et al . (2006), Meng et al . (2006) and is characterized by the misfit values ranging from 16 to 36.…”

“…2001; Altamimi et al . 2002; Prawirodirdjo & Bock 2004; Meng et al . 2006) but are considerably different from NUVEL‐1A estimate (DeMets et al .…”