He is the co-creator of the Volcanic explosivity index and specializes in volcanic prediction .
Christopher G. Newhall is a volcanologist , formerly with the U.S. Geological Survey and since 2008 at the Earth Observatory of Singapore .
Christopher G. Newhall is the volcanologist of the Volcanic explosivity index and specializes in volcanic prediction .
Christopher G. Newhall is a volcanologist , formerly with the U.S. Geological Survey and since 2008 at the Earth Observatory of Singapore .