Deep ocean basins cover almost 70% of Earth's surface, and they contain 96% of the planet's life-sustaining water. The oceans support the biosphere by modulating global climate and hydrology, and are home to the marine organisms that form the diverse base of the global ecosystem. Geology's unifying paradigm, the theory of plate tectonics, arose from deep-sea discoveries of the 1950s and 1960s. The title of marine geologist Philip Kuenen's 1958 paper, "No Geology without Marine Geology," rings especially true with hindsight of late twentieth century advancements in the field of marine geology.

The nature of the seafloor was an unrevealed mystery until the mid-nineteenth century; scientists and artists alike envisioned the deep sea as a lifeless soup of placid water, contained in a bowl of static rock. By the late 1860s, however, controversial theories of the origin of life by evolution and the vastness of geologic time...