Very long baseline interferometric (VLBI) measurements using the antenna near Shanghai, China, between 1987 and 1994 show that this site moves at 8¿0.5 mm/yr (1&sgr;) in the direction N116.5 ¿E (¿4.1¿) with respect to VLBI sites in Europe on the Eurasia plate. Independent measurements of the site at Shanghai with respect to sites on nearly all major plates (Eurasia, North America, Pacific, Australia, and Africa) determine this velocity. South China translates east-southeast relative to Eurasia more slowly than 20% of India's roughly 50 mm/yr convergence rate with Eurasia and hence accommodates only a small fraction of India's penetration into Eurasia. Apparently, crustal thickening absorbs most of India's convergence. The relatively low speed of south China supports treatments of continental lithosphere as a thin viscous sheet whose strength is governed primarily by power law creep in the upper mantle, and not by friction in the crust. ¿ American Geophysical Union 1996 |