The migration of the crustal deformation peak area in the eastern Himalayan Syntaxis inferred from present-day crustal deformation and morpho-tectonic markers

The present-day Global Positioning System (GPS) velocity field shows that the Indian Plate is not a complete rigid block, as its northeastern corner has been torn off and clockwise rotating relative to the main part. With the updated GPS velocity data, the Euler vector of the northeastern corner of the Indian Plate relative to the stable main plate is deduced as (89.566 +/- 0.06 degrees E, 26.131 +/- 0.05 degrees N, 1.34 +/- 0.11 degrees/Myr). The peak area of the present-day crustal deformation is located in the Chayu deformation belt with the compressional dilation strain rate over 160 nanostrain/yr. However, the Namche-Barwa Syntaxis with the massive crustal thickening and intense surface erosion is generally considered to be the previous locus of the strongest compressional stress in the Eastern Himalayan Syntaxis over long geological timescales. Thus, there is a discrepancy between the previous and present-day crustal deformation peak areas. We argue the migration of the crustal deformation peak area with a total distance of about 120 km and ascribe it to the variation of stress conditions caused by northeast India's clockwise rotation. (C) 2021 Editorial office of Geodesy and Geodynamics. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co. Ltd.