What you can’t see may astound you. The largest unexplored region of Earth is the ocean. Beneath its churning surface, oceanographers have recently discovered the largest volcano in the world – perhaps in the solar system. Find out what is known – and yet to be discovered – about the marine life of the abyss, and how a fish called the bristlemouth has grabbed the crown for “most numerous vertebrate on Earth” from the chicken. Plus, the menace of America’s Cascadia fault, which has the potential to unleash a devastating magnitude 9 earthquake.  Follow Dr. Sager’s voyage back to Tamu Massif in Fall 2015. Guests  • Bruce Robison – Deep sea biologist, Monterey Bay Aquarium Research Institute • William Sager – Marine geophysicist, Earth and Atmospheric Sciences, University of Houston • Chris Goldfinger  - Marine geologist, geophysicist, paleo-seismologist, Oregon State University  Learn more about your ad choices. Visit megaphone.fm/adchoices