Milwaukee Deep Milwaukee Deep Milwaukee Deep, also known as The Milwaukee Depth, () is the deepest part of the Atlantic Ocean and is part of the Puerto Rico Trench. It has a maximum depth of at least . It is just north of the coast of Puerto Rico at "Punto Palmas Altas" in Manatí. This ocean floor feature is named for the USS "Milwaukee" (CL-5), a U.S. Navy Omaha class cruiser, which discovered the Milwaukee Deep on February 14, 1939 with a reading of . On August 19, 1952, the U.S. Fish and Wildlife vessel "Theodore N. Gill" obtained a reading of
Canfield ocean during the Great Oxygenation Event. The presence of oxygen in the deep ocean made the formation of BIF impossible, which is seen in ocean sediment records. Conversely, the Canfield Ocean theory postulates that deep ocean water remained anoxic long after the Great Oxidation Event, and he argued that the euxinic conditions in the deep ocean ceased the deposition of BIF in ocean sediments. Euxinic describes anoxic conditions in the presence of hydrogen sulfide. Euxinic ocean conditions, a term describing restricted hydrologic circulation that lead to stagnant or anaerobic conditions, are the likely factor leading to sulfidic oceans. Canfield ocean The