Abstract:
The India-Eurasia collision has created high mountains in the Himalayan plate boundary system, which has led
to numerous earthquakes in this region and released part of the elastic strain accumulated over years. In this
study, the present-day deformation pattern is derived from geodetic mode Global Positioning System (GPS)
measurements obtained during 2005–2016 from 16 campaign sites in the Kumaun province of the central
Himalaya. GPS derived horizontal velocity vectors are in the range of 1–9 mm/yr and 27–38 mm/yr with respect
to stable India and Eurasia reference frames respectively. To understand the interseismic strain partitioning in
the study region, we consider the uniform slip dislocation model over the fault in an elastic, isotropic and
homogeneous half-space medium. The model indicates the Main Himalayan Thrust (MHT) fault is locked to a
depth of ∼20 km and slips at a rate of 17.2 ± 1 mm/yr with a dip angle of ∼7°. This MHT slip rate build-up
corresponds to a moment deficit of 8.4 ± 1 × 1018 Nm/yr due to locking of the fault beneath the Kumaun
Himalaya. The total seismic strain accumulation of 61 × 10−6 estimated from the geodetic data suggests the
possibility of large earthquakes (typically magnitude 8 and above) with the recurrence interval of around
600 years in the Kumaun Himalayan region.
