How Japan's Seikan Tunnel Survives 20 Tons of Seawater Every Minute

240 m below sea level, Japan's Seikan Tunnel still leaks 20 tons of seawater a minute. Japan dug this undersea tunnel to Hokkaido after a 1954 typhoon killed 1,430 people. Volcanic rock let the sea in four times. Engineers learned to seal the rock first. Now 1.6 million people a year ride under it. #SeikanTunnel #Japan #Megaprojects #Engineering #Tunnel #Hokkaido #Documentary DISCLAIMER ____________________________________ This is not engineering advice. Everything here is for informational and entertainment purposes only. Contact an engineer licensed to practice in your area if you need professional advice or services. All non-licensed clips used for fair use commentary, criticism, and educational purposes.