Weather has always been one of the most dynamic and complex forces shaping our planet, but now it's intensifying in varied and complex ways. Extreme Weather takes us to the frontlines where few have gone.

Among the melting tidewater glaciers of Alaska, National Geographic Emerging Explorer Dr. Erin Pettit leads a young team of researchers into the splash zone at the face of Dawes Glacier aboard a boat custom-designed to get as close as possible to the calving ice. Using a variety of instruments, her team works to measure the rate of melting to help build a more accurate model of global ocean level rise.

Photo credit: National Geographic