The Main Frontal Thrust is the youngest and southernmost of the great thrust faults that build the Himalaya, running for more than 2,000 kilometres along the mountain front from Pakistan through India and Nepal to the eastern ranges. It marks the boundary where the Himalayan foothills override the flat Indo-Gangetic plains.
As the surface expression of the Main Himalayan Thrust ramp at depth, this fault carries the entire mountain belt southward over the Indian Plate. Convergence across the front absorbs roughly two centimetres per year, and the fault ruptures in great earthquakes as the accumulated strain is suddenly released along the buried decollement.
The Main Frontal Thrust is capable of generating some of the largest continental earthquakes on Earth, with surface ruptures inferred from great medieval events and the potential for future magnitude 8 or larger quakes. Its proximity to hundreds of millions of people across northern India and Nepal makes it one of the most dangerous fault systems in the world.