This is a comprehensive treatment of the remarkable discoveries made during the last twenty-five years concerning relief and structures under the world ocean. The author deals with a host of isolated, deep-sea volcanoes; with gigantic submarine chains of mountains; and with thousands of submarine valleys, deeply cut in the submerged flanks of continents and large islands. Originally published in 1942. A UNC Press Enduring Edition - UNC Press Enduring Editions use the latest in digital technology to make available again books from our distinguished backlist that were previously out of print. These editions are published unaltered from the original, and are presented in affordable paperback formats, bringing readers both historical and cultural value.