Uttarakhand is now included in Zone Six, a highly earthquake-prone zone; the number of sensors and sirens will be increased
Uttarakhand has been included in the highly seismic Zone Six. Previously, the state’s districts were divided into Zones Four and Five. Now, the Bureau of Indian Standards (BIS) has released a new seismic zonation map in its code of practice for earthquake-resistant design of structures (IS 2025). This map places Uttarakhand, along with other Himalayan states, in the extremely vulnerable Zone Six. According to scientists, this means people will have to be more vigilant about construction activities throughout the state.
According to Vineet Gahlot, Director of the Wadia Institute of Himalayan Geology, the Bureau of Indian Standards releases seismic zoning maps. The previous map was released in 2016. Now, in the new map released after about nine years, all the hilly states have been uniformly included in Zone Six. This means that the seismic risk in Uttarakhand is the same as in Jammu and Kashmir. Director Gahlot says that this plays a crucial role in the construction of large dams, roads, buildings, etc. Now, there will be uniformity in construction work within the hilly states. Earlier, Rudraprayag, Chamoli, Bageshwar, and Pithoragarh, which were in Zone Five, were considered the most seismically sensitive districts.
There is not much difference in the Himalayas from a geological perspective: Bisht
MPS Bisht, Head of the Department of Geology at Srinagar Garhwal Central University, says that there is not much difference in the Himalayas from a geological perspective. Their rocks, boundaries, plates, etc., are similar. In the previous zoning, the state was placed in two zones. Now it has been placed in a single zone (Six). Its sensitivity has been increased. In such a situation, we will have to be more vigilant. He explained that seismic zoning is done by including past earthquake events, intensity, and other aspects.
The number of sensors and sirens will be increased in the state.
There is a continuous collision between the Indian and Eurasian tectonic plates. Due to this, the region remains susceptible to earthquakes. Since 1911, the state has experienced 11 major earthquakes with a magnitude of more than six on the Richter scale. Now, in view of the earthquake risk, other steps will be taken in the state, including increasing the number of sensors and sirens.
The biggest earthquake in the state occurred on August 28, 1916. A 6.96 magnitude earthquake was recorded on that day. However, if we consider the 49 years between 1975 and 2024, no earthquake with a magnitude of seven or more on the Richter scale has occurred. Most earthquakes have been of magnitude three to four on the Richter scale. There have been 320 earthquakes of magnitude three to four, 90 of magnitude four to five, 34 of magnitude five to six, and three of magnitude six to seven.
Number of sensors to be increased
Vinod Kumar Suman, Secretary of Disaster Management and Rehabilitation, says that all necessary steps are being taken in view of the possibility of earthquakes. A mock drill regarding earthquakes was recently conducted. In addition, the number of sirens and sensors will be increased. Steps will also be taken to raise public awareness.
The state was previously divided into two zones
Previously, the state was divided into two zones in terms of earthquake vulnerability. The most sensitive Zone 5 included Rudraprayag, Chamoli, Bageshwar, and Pithoragarh. Zone 4 included Uttarkashi, Tehri Garhwal, Dehradun, Haridwar, and Pauri Garhwal.
In 2021, four districts were included in the most vulnerable districts
In a reply given in the Lok Sabha in 2021, the Minister of State for Science and Technology and Earth Sciences provided information on 38 cities and towns that are highly vulnerable to earthquakes. These include Almora, Nainital, Dehradun, and Roorkee.
