An alien approaching Earth for the first time would observe a watery planet but would have no clue as to what lies beneath the blue-gray liquid surface. This book unveils and illuminates, in ways never before possible, that hidden world and the astounding processes that occur at the seafloor and within the oceanic crust. Drawing from unparalleled imagery and data from twenty-first century technology, which includes human-occupied and robotic vehicles, sophisticated sensors and analytical techniques, the authors have succeeded in “pulling the plug” on the global ocean so that the awe-inspiring terrane of the ocean floor and processes that form it are revealed.

It was 44 years ago that Bruce Heezen and Charles Hollister published their seminal book, The Face of The Deep, an engaging and informative text that used analog seafloor photographs to highlight and interpret the myriad processes operating in the global abyss. Discovering the Deep sets a new benchmark for a comprehensive treatise about visualizing the seafloor, how ocean crust forms, and the amazing life forms that thrive in one of the most extreme environments on Earth – submarine hot springs. It presents up to date, integrated multidisciplinary concepts about the mid-ocean ridge and its role in plate tectonics and developing the architecture of the oceanic crust. The authors also synthesize published data from mid-ocean ridge analogs on land – ophiolites – to better understand how oceanic crust is generated and the far-reaching implications of these processes for interpreting Earth and ocean history.

As a student of Heezen, a contemporary of Hollister, and someone who has spent most of his career studying the mid-ocean ridge using ships and the submersible Alvin, I was drawn into all aspects of this compelling and masterful synthesis, especially the high-resolution images of mid-ocean ridge volcanic and hydrothermal terranes and biota. The more than 500 stunning images of the seafloor, many never before published, were taken using the latest in deep-sea digital camera and lighting technology.