Great earthquakes are a permanent, if intermittent fixture of the Himalaya. A major earthquake is due to occur in the "seismic gap" which exists between Kathmandu and Dehradun. The most disastarous event in history will be pale shadow of the next great earthquake.
Five minutes is not a long time unless something really unpleasant is happening. Two million square miles of northern India and western Nepal shook violently for 5 minutes starting at 2:13 in the afternoon of 15 January 1934. The occasion was the Great Bihar Earthquake. It took a further 15 minutes for hanging lamps to stop swinging in Calcutta. It took many days for the dust to settle from landslides in the mountains of Nepal. It took many weeks for sand ejected from the ground to be removed from fields and villages in Bihar, and the roads and railways of Bihar to be brought into service. It took many years to reconstruct the tens of thousands of damaged buildings in hundreds of villages and cities. In the sixty years since this event, we have learned that such great earthquakes are necessary events in the building of the Himalaya. Some seismologists believe that the next great earthquake may be long overdue.
Great Earthquakes Are Inevitable
The processes responsible for the collision between the Indian and Asian tectonic plates are found deep below the Earth´s surface and because of this we know of them only indirectly. A gravitational depression of the Earth´s shape near Tibet suggests that an almost vertical current of viscous rocks plunges deep into the Earth´s mantle, dragging India and southern Tibet towards each other and both of them northward. The result is that each year India approaches Tibet by 2cm, causing the intervening rocks to be squeezed horizontally and upward. The Himalaya is the result of this collision.
The Great Bihar Earthquake was the most recent of three great earthquakes that have occurred in the Himalaya in the past 100 years. The other two involved similar intensities and durati on of shaking:The 4 April 1905 Kangra earthquake to the East and the 10 June 1897 Assam earth¬quake to the west. The 1934 earthquake destroyed buildings in hundreds of vill¬ages and dozens of cities, many of them in northern India, and hence became known as the "Bihar earthquake". But it equally well could have been called the Kath-mandu Earthquake, or the Patna Earth¬quake, or named after any one of the many damaged cities. In fact, for several days after the Bihar earthquake it was thought that the epicentre was at Darjeeling.