Next Teesta Tunnel Disaster: Methane Risks and Himalayan Infrastructure Vulnerability:
A sudden explosive release of suspected methane and other toxic gases inside the under-construction Head Race Tunnel of the Teesta Stage VI Hydropower Project at Samardung in Sikkim’s Namchi district killed several workers and left others trapped.The incident highlights the serious safety and geological risks associated with large infrastructure projects in the fragile Himalayan region.Methane is a colourless, odourless and highly flammable gas that may accumulate naturally in underground rock formations and confined spaces such as tunnels.When methane mixes with air in a particular concentration, sparks generated by drilling or other construction equipment can ignite it and cause an explosion.Drilling during the construction of the Head Race Tunnel may have disturbed methane-bearing rocks, causing the gas to escape suddenly into the tunnel.Methane may occur as natural gas trapped within porous rocks or as isolated gas pockets in young and fragile geological formations.In mountainous regions with coal-bearing or carbon-rich strata, methane can form through the decomposition of ancient organic matter over millions of years.Waterlogged valleys and hilly depressions may create oxygen-deficient conditions in which microorganisms decompose organic material and release methane.
