Tectonic & Non-Tectonic Deformation as revealed by GNSS Studies in the Himachal region of NW Himalaya: Towards Assessment of Seismic Hazard Potential

Owing to the varying oblique nature of tectonic convergence along Himalayan arc, NW Himalaya undergoes significant dextral arc-parallel deformation in addition to arc-normal shortening. We shall present our findings from 10 newly established Permanent GNSS Stations across the Punjab and Himachal Himalaya with data span up to 4 years. In addition to the long-term tectonic signal giving estimates of the ongoing inter-seismic strain accumulation, the annual and semi-annual transients allowed for the characterization of the deformation in Himachal Himalaya. The hydrological loading, non-tidal atmospheric loading and non-tidal oceanic loading models were utilized to analyse the observed transient behaviour at GPS stations and increase the accuracy of the velocities. The Groundwater Storage and Total Precipitation Rate dataset from the Global Land Data Assimilation System (GLDAS 2.2 CLS Model and GLDAS 2.1 NOAH Model) were used to decipher certain trends observed in the GPS time-series. Our GPS Velocity estimates along with a few constraints from published literature were used to estimate the slip rate, the locking width and depth along Main Himalayan Thrust across Himachal Himalaya. We attempt to estimate elastic strain partitioning amongst various geological features using constraints from our results and compare them with the published slip rates along individual active faults Main Frontal Thrust, Kangra Valley Fault (KVF, a dextral strike-slip fault) and Jwalamukhi Thrust (JMT, a reactivated out-of-sequence Thrust Fault) calculated using Paleoseismological studies, River-terrace studies, Be-10 surface exposure dating techniques, to understand the regional strain release behaviour through seismic and aseismic activity as the study region lies west of the Delhi-Haridwar Ridge being underthrusted beneath the Himalaya, a major Fault Segmentation Boundary proposed by several researchers. We assess the earthquake potential of KVF and JMT. The region hasn't experienced an earthquake since the highly devastating 1905 Kangra earthquake (Mw ~ 7.8), hence posing significant future risk to the millions of inhabitants. The important findings shall be presented in the local to regional context with focus on their seismic hazard potential and furthering the understanding of Himalayan tectonics.