India-based Neutrino Observatory (INO) is a particle physics research project under construction to study atmospheric neutrinos in a 1,300 meters deep cave near Theni, in Tamil Nadu. This project is anticipated to provide a precise measurement of neutrino mixing parameters. A neutrino is an elementary particle that interacts only via the weak subatomic force and gravity.

Current Status

Environmental clearance for the project has been obtained. Application for Wildlife Clearance and Tamil Nadu Pollution Control Board (TNPCB) has been submitted. An 85 ton prototype mini-ICAL detector has been built and is working at IICHEP premises in Madurai.


Approximately 2 km long tunnel and the laboratory caverns is required to be made using controlled blasting and take about 3 years to complete. The vibrations will not be above the acceptable limits of less than 1 mm/sec beyond about 200 m distance from the blast zone.

The total amount of excavated rock is about 230,000 cubic metres. This is comparable to that removed from railway or road tunnels of similar length.

Impact of INO Construction

The vibrations reduce to negligible levels beyond a few hundred metres. Dams such as Vaigai and Mullaiperiyar which are about 30 km away will not be affected. In fact, these vibrations will not even be felt in the nearby villages which are a few kms. away.

There is no possibility of seismic events triggered by work at the INO site. However, seismic monitoring has to be carried out during construction as an abundant measure of caution.