The Bureau of Indian Standards (BIS) of the Government of India has updated the National Seismic Hazard Map. The old Seismic Hazard Map divided the country into four zones (II, III, IV, and V), but the new map adds a new Zone VI.

The entire Himalayan belt, from Arunachal Pradesh to Jammu and Kashmir, has been designated Zone VI. This means that the Himalayan belt remains vulnerable to large or destructive earthquakes. The old Seismic Hazard Map had only five zones, but the new one has expanded to six.

The Himalayas were divided into two zones in the old map

The old Seismic Hazard Map divided India’s Himalayan region into two zones: Zones IV and V. The division of the region into seismic zones means that any construction work, or infrastructure development, in these areas should be carried out based on the earthquake intensity.

Reasons for Putting These Areas in Zone 6

The report released by the BIS recommends paying special attention to the region between Dehradun and Mohand in Uttarakhand, the Terai belt, and cities along the Ganga-Yamuna River. This is primarily because the Himalayan Frontal Thrust and its associated sub-fault lines have not experienced any major earthquakes in the past 500 years. Consequently, scientists estimate that significant energy has accumulated underground.