Seismic assessment of a temporary deployment in the Kingdom of Bhutan using double-­difference tomography 

Tuesday, 16 December 2014
Chanel A Perez1, Aaron A Velasco1, Ellen M Syracuse2, Monica Maceira2 and Haijiang Zhang3, (1)University of Texas at El Paso, Geological Sciences, El Paso, TX, United States, (2)Los Alamos National Laboratory, Los Alamos, NM, United States, (3)University of Science and Technology of China, Hefei, China
The Kingdom of Bhutan is located on the eastern edge of the Himalaya range. As an area of a major continental-continental collision, Bhutan Himalaya has been subject to a considerable amount of deformation and transpression, and it contains features of the five major shear zones of the Himalayas. Extensive seismic analysis of the region, however, is lacking due to sparse coverage and complexity of its crustal structure. We examine seismic event data from a temporary seismic network deployed in the Kingdom of Bhutan (2002-2003) using the double difference tomographic inversion technique TomoFDD, which allows for the joint inversion of event relocations and seismic velocity structure. Our primary focus is on ~200 regional events surrounding the five-station network. The events are located between 86° and 100°E longitude, and 18° and 31°N latitude, and with depths between 10 and 400 km. To extend our model area, we also incorporate GSN stations LSA, KMI, and CHTO. Prior analysis of this dataset consisted of event location, relocation, and 1D velocity modeling. We leverage on previous studies and build a new 3D seismic velocity model of the crust and upper mantle underneath the Bhutan region to gain further insight on the seismicity and crustal assessment.