An area of around 1000 to 2000 square miles slid over a zone with the cities of Kathmandu and Pokhara on one direction and the entire Himalayan range in the other. The shift could be from one to 10 feet. The earth’s crust or lithosphere below Bihar slid below Nepal along a zone from Bharatpur, through Hetauda, to Janakpur.
The fact is that the whole of North India is sliding north-northeast beneath Nepal constantly. This process began millions of years ago and this is what created the Himalayas. The sliding is abrupt in nature and takes place at different patches at different times.
In the last 81 years since the 1934 Bihar earthquake which led to around 10,000 deaths, the Indian land mass has slid about 12 feet under Nepal. According to Geophysicists the entire Indian Subcontinent is slowly and surely sliding under Nepal and Tibet at a rate of around 1.8 inches per year. The entire region from Pakistan to Myanmar is very vulnerable to earthquakes due to this movement. The Nepal earthquake was neither unusual nor unexpected. This is because the Saturday earthquake comes under the category of great earthquake and these quakes have a cycle of approximately 50 years or more. Therefore this earthquake was expected.
image credit: img-hd.com