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Utilizing an updated dataset of 145 GNSS surface velocities, this study examines the fault slip rate and fault geometry along the Main Himalayan Thrust (MHT) in the central Himalaya. Employing a Bayesian inversion model, the present analysis reveals that the upper portion of the MHT ramp exhibits full locking, while the lower flat displays creeping motion. The estimated locking depth and fault depth of MFT range from 4.3 ± 2.6 km to 9.7 ± 2.2 km and 13.5 ± 3.1 km to 15.8 ± 1.9 km, respectively, along the central Himalaya. Further, the slip rate along the transition zone lies in the range of 1.4 ± 0.8 mm/yr to 2.7 ± 0.5 mm/yr. Considering the amount of uncertainties as ~1–2 mm/yr in GNSS velocities, the study suggests that the transition zone along the middle flat of the MHT also exhibits locking behavior. Thus, the estimated locking depth extends to ~15.0 km down-dip and covers a horizontal distance of ~90 km (locking line) on the surface, reaching the foothills of the Higher Himalaya. Furthermore, along the deeper flat of the MHT, the slip rate ranges from 19.4 ± 2.5 mm/yr in the west to 12.8 ± 1.6 mm/yr in the east along Nepal Himalaya. The analysis also calculates the slip deficit rate along the MHT fault plane, revealing values of ~15.1 mm/yr in western Nepal, ~12.7 mm/yr in central Nepal, and ~10.6 mm/yr in eastern Nepal. These slip deficit rates across different segments of central Nepal indicate the potential for large earthquakes in the region. The results are further supported by a resolution test using a checkerboard synthetic model, demonstrating the capability of the GNSS network to capture the slip rate along the MHT. These findings inevitably contribute to a comprehensive assessment of the seismic hazard potential in the central Himalayan region. [ABSTRACT FROM AUTHOR]

The ability to determine the current state of seismic cycle of large sized earthquakes is of profound importance in societal policymaking and disaster preparation. In this article, we present a probabilistic formulation of event-based natural time counts to develop earthquake potential score (EPS) at 36 cities from northeast India, Bangladesh, and adjoining areas. The time-dependent natural time analysis provides an attractive regional seismic hazard evaluation method, because it (1) exhibits spatiotemporal and clustering invariability, ensuring model consistency, (2) considers "seismic cycles" for a network of faults in a defined area, and (3) enables some physical interpretations aligned with earthquake generation process characterized by stress accumulation and moment release. The modeling results for M ≥ 6 events reveal that EPS values lie between 41 and 94%, with the scores of Agartala (91%), Aizawl (84%), Dimapur (80%), Guwahati (41%), Imphal (90%), Malda (70%), Shillong (52%), Siliguri (73%), Barisal (59%), Chittagong (94%), Comilla (88%), Dhaka (78%), Mymensingh (81%), Narayanganj (77%), Rangpur (55%), and Sylhet (60%). These values essentially serve as a yardstick to statistically assess the current state of regional seismic cycle progression in the study region, bringing out some key information to the decision-makers, engineers, scientists, and citizens to improve earthquake preparedness and mitigation strategies. [ABSTRACT FROM AUTHOR]