Crustal deformation characteristics of Sichuan-Yunnan region in China on the constraint of multi-periods of GPS velocity fields

摘要: Abstract In order to obtain deformation parameters in each block of Sichuan-Yunnan Region (SYG) China by stages and establish a dynamic model about the variation strain rate fields surface expansion this area, we taken Global Positioning System (GPS) sites velocity region as constrained condition advantage calculation based on spherical surface. We also analyzed active blocks whole SYG before after Wenchuan earthquake, near epicenter earthquake detail. The results show that, (1) Under effects carving from India plate crimping potential energy Tibetan Plateau for long time, there is certain periodicity crustal SYG. And period change occurrence have good agreement. (2) differences GPS relative Eurasian reference frame shows that Ya'an mainly affect movement central southern part SYG, average difference 4–8 mm/a 2–4 mm/a earthquake. (3) For changed 10 20 nanostrian/a 40–50 but Ya’an value increased 15 30 nanostrian/a. (4) has parameter more or less. Especially, Longmen Chengdu epicenter. research provides fundamental material study mechanism push extrusion north-east crimp Qinghai Tibet Plateau, it support stress prediction Sichuan Yunnan region.