The Underworld, Journeys to the Depths of the Ocean

John Wells speaks with New York Times best-selling author Susan Casey who has just written "The Underworld, Journeys to the Depths of the Ocean." Casey writes “Eighty percent of the seafloor has never been charted in any kind of sharp detail. Yet the deep ocean — defined as the waters below six hundred feet — covers sixty-five percent of the earth’s surface and occupies ninety-three percent of its living space. The deep isn’t merely a part of our planet — it is our planet.”