The book is aimed to present the seismic hazard estimation in two seismic gap regions of Himalaya. The Deterministic Seismic Hazard Assessment (DSHA) of a region using strong motion simulation of earthquake sources is nowadays very popular. In the present book, the seismic hazard maps of NE Himalaya and Uttarakhand Himalaya based on peak ground acceleration are presented. The semi empirical strong motion simulation technique is used to calculate PGA values in a grid pattern. The semi empirical technique is further modified to estimate component wise strong ground motion. The modified technique is tested with 2004, Niigata-ken Chuetsu, Japan earthquake. To check its efficacy, the simulated longitudinal, transverse and vertical components of strong ground motion are compared with the observed strong motion data of this earthquake recorded by KiK-net strong motion network. Finally a great (scenario) earthquake of M=8 in the central seismic gap region of Himalaya is simulated with the new technique. The strong motion parameters like peak ground acceleration, peak ground velocity, peak displacement and response spectra at 5% damping are computed and presented in the book.