Blake Plateau

The Blake Plateau lies in the western Atlantic Ocean off the coasts of North Carolina, South Carolina, Georgia, and Florida in the southeastern United States. The Blake Plateau lies between the North American continental shelf and the deep ocean basin extending about 145 km east and west by 170 km north and south, with a depth of about 500 m inshore sloping to about 1,000 m about 375 km off shore, where the Blake Escarpment drops steeply to the deep basin. The Blake Plateau and the associated Blake Ridge and Blake Basin are named for the United States Coast and Geodetic Survey steamer, in service from 1874 to 1905, which was the first ship to use steel cable for oceanographic operations and pioneered deep ocean and Gulf Stream exploration. George S. Blake′s hydrographic survey lines first defined the plateau that now bears the ship's name.

Blake Plateau has the world's largest known deep-water coral reef, comprising a 6.4 million acre reef that stretches from Miami to Charleston, S. C.

History
In July 1880 George S. Blake under the command of Commander John R. Bartlett, U.S.N., was working with sounding gear designed by Lieutenant Commander Charles Dwight Sigsbee in cooperation with Alexander Agassiz, who collected biological samples and examined the Gulf Stream running eastward from Cape Romain when, in taking frequent soundings eastward, "depths on this line were unexpectedly small, the axis of the Gulf Stream being crossed before a depth of three hundred fathoms (1,800 ft) was found" with a bottom of "hard coral" and little life. This was an early indication of the plateau that would in the future carry the ship's name. In 1882 Commander Bartlett described the plateau:

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Bartlett reported the scouring effect of the current on the plateau, noting that on each side of the current the sounding cylinder, a device for sampling the nature of the bottom with the sounding, brought up ooze. Within the current the "bottom was washed nearly bare", with particles being small and broken pieces of coral rock and so hard the sharp edge of the brass cylinder was bent.

Geology
Due to unusual features of the plateau, particularly scouring by the Florida Current and the Antilles Current that merge over the plateau to form the Gulf Stream, mineral deposits, particularly manganese nodules, have long been of interest. Methane and other gas hydrates are also found on the plateau.

Biology
The Blake Plateau, once believed to be a "bleak, current-swept plain," was known to have some biological communities including Lophelia pertusa reefs that support communities as well as communities supported by gas hydrates. In fact, by 2024 it was discovered that Blake Plateau has the world's largest known deep-water coral reef, comprising a 6.4 million acre reef that stretches from Miami to Charleston, S. C. The area is composed of nearly continuous coral mound features that span up to 500 kilometers (310 miles) long and 110 kilometers (68 miles) wide. One spot, nicknamed "Million Mounds", is the largest part of the reef. It is composed of a stony coral and is commonly found at depths of 656 to 3,280 feet. The reef was discovered during sonar investigations beginning in 2019, and was announced in January 2024.

Commercial fishermen have begun exploiting deep sea fish on the plateau with studies being undertaken on the viability of such fishing, as these fish, although large, grow slowly. Biological sampling of the deep bottom is difficult under the Gulf Stream with the consequence that the fauna is relatively poorly known.