The Himalaya Range has been undergoing crustal shortening along the 2,400 km long northern edge of the Indian Plate which resulted in the formation of several thrust faults including the Main Central Thrust (MCT), the Main Boundary Thrust (MBT) and the Main Frontal Thrust (MFT). The MCT consists of three sub-thrusts: MCT I, MCT II and MCT III. Many earthquakes have occurred along these thrust faults. It is thought that the Chamoli earthquake in 1999 was associated with these fault systems.