大规模GPS揭示中国现今地壳构造形变特征

利用全国260多个陆态网络连续站以及2 000多个陆态网络区域站2011—2015年观测数据,计算分析中国大陆现今整体地壳构造形变特征以及板内应变场空间分布特征。根据密集、大范围的GPS速度场可知中国大陆现今整体速度场依然呈现西强东弱的态势,其中最大值出现在喜马拉雅地区,一般速率在35~42mm/a之间,而川滇地区形成的右旋剪切带的形变特征最为醒目,其西南部最小速率在3~9mm/a之间,北部最大速率在17~23mm/a;由应变场的空间分布可以看出应力最大的地区主要是喜马拉雅、昆仑山中部、川滇地区的鲜水河断裂带、天山地区以及京津唐地区;东部沿海地区应变速率表现为东西拉张型,主要是由于2011年日本大地震对该地区的影响还未完全消退造成的。

Present-day Crustal Tectonic Deformation Characteristics of China Inferred from Large-scale GPS

This paper calculated the tectonic deformation characteristics of mainland China and the characteristics of the strain field in the plate space distribution, using more than 260 continuous CMONOC sites and more than 2,000 area stations, that are the latest observation data. According to the intensive, wide range of GPS velocity field shows strong east and west weak trends from the entire velocity field in mainland China. The maximum velocity appeared in the Himalayan region, with a general rate between 35 and 42 mm/a. The Sichuan-Yunnan region dextral shear zone formed by the deformation characteristics of the most striking that the southwest of the minimum rate is between 3 to 9 mm/a, north of maximum rate in 17~23 mm/a. It can be seen from the spatial distribution that the largest strain-stress are mainly from the following regions: Himalayan, Kunlun Mountains, Sichuan and the Yunnan areas of fresh water river fault zone, Tianshan region, and Beijing-Tianjin area. The strain rate of the east coast shows tension that is mainly due to the earthquake in Japan in 2011, although the influence of the region has not completely subsided.