Jade Sridevi, Shrungeshwara T S, Kumar Kireet, Choudhury Pallabee, Dumka Rakesh K, Bhu Harsh
CSIR-4PI, CSIR Fourth Paradigm Institute (Formerly CSIR-CMMACS), Wind Tunnel Road, Bangalore, 560 037, India.
GBPNIHESD, GB Pant National Institute of Himalayan Environment and Sustainable Development (Formerly GBPIHED), Almora, India.
Sci Rep. 2017 Sep 12;7(1):11439. doi: 10.1038/s41598-017-11697-w.
We estimate a new angular velocity for the India plate and contemporary deformation rates in the plate interior and along its seismically active margins from Global Positioning System (GPS) measurements from 1996 to 2015 at 70 continuous and 3 episodic stations. A new India-ITRF2008 angular velocity is estimated from 30 GPS sites, which include stations from western and eastern regions of the plate interior that were unrepresented or only sparsely sampled in previous studies. Our newly estimated India-ITRF2008 Euler pole is located significantly closer to the plate with ~3% higher angular velocity than all previous estimates and thus predicts more rapid variations in rates and directions along the plate boundaries. The 30 India plate GPS site velocities are well fit by the new angular velocity, with north and east RMS misfits of only 0.8 and 0.9 mm/yr, respectively. India fixed velocities suggest an approximate of 1-2 mm/yr intra-plate deformation that might be concentrated along regional dislocations, faults in Peninsular India, Kachchh and Indo-Gangetic plain. Relative to our newly-defined India plate frame of reference, the newly estimated velocities for 43 other GPS sites along the plate margins give insights into active deformation along India's seismically active northern and eastern boundaries.
我们根据1996年至2015年期间在70个连续站点和3个非连续站点进行的全球定位系统（GPS）测量，估算了印度板块的新角速度以及该板块内部及其地震活跃边缘的当代变形速率。从30个GPS站点估算出一个新的印度-国际地球参考框架2008（India-ITRF2008）角速度，这些站点包括板块内部西部和东部区域的站点，而这些区域在以往研究中没有代表性或仅有稀疏采样。我们新估算的印度-ITRF2008欧拉极显著更靠近板块，角速度比之前所有估算值高约3%，因此预测沿着板块边界的速率和方向变化更快。30个印度板块GPS站点的速度与新角速度拟合良好，北向和东向均方根偏差分别仅为0.8和0.9毫米/年。印度固定速度表明板块内部存在约1-2毫米/年的变形，可能集中在半岛印度、卡奇和印度河-恒河平原的区域位错、断层沿线。相对于我们新定义的印度板块参考框架，新估算的沿板块边缘的其他43个GPS站点的速度，为印度地震活跃的北部和东部边界的活动变形提供了见解。
