Earthquake Hazard Assessment for Dehradun, Uttarakhand, India, Including a Characteristic Earthquake Recurrence Model for the Himalaya Frontal Fault (HFF)

The seismic hazard has been computed for the city of Dehradun, Uttarakhand, India. The city lies in the Himalayan foothills between two faults: the Main Boundary Thrust (MBT) and the Himalayan Frontal Fault (HFF). The contributions from these two faults have been modelled differently in a probabilistic model. While the MBT has been modelled with a Poissonian earthquake distribution, the HFF has been modelled both with a characteristic earthquake recurrence model and a Poissonian model. The hazard scenarios reveal different patterns depending on the classical approaches and the characteristic models applied, and the obtained results indicate that Dehradun may experience PGA shaking around 2.2 m/s2 for 225 years return period and around 4.6 m/s2 for a 2,500 years return period.