The Nepal earthquake, which has killed at least 3200 people, was particularly destructive because it occurred at only 10km depth, AIR Worldwide says.

The catastrophe modeller says the event was estimated at magnitude 7.5 when it struck on Saturday, but this has since been revised to 7.8.

AIR Worldwide says at least four earthquakes larger than 7.5 have occurred along the main Himalaya fault since 1900.

The 7.6 Kashmir earthquake in 2005 killed more than 46,000 people.

Many deaths in Nepal have occurred from the collapse of unreinforced masonry buildings.