Peacock Sound is an ice-filled sound

Sound (geography)

In geography a sound or seaway is a large sea or ocean inlet larger than a bay, deeper than a bight and wider than a fjord; or it may be defined as a narrow sea or ocean channel between two bodies of land ....

, 216 kilometres (134 mi) long and 64 km (40 mi) wide, separating Thurston Island

Thurston Island

Thurston Island is an ice-covered, glacially dissected island, long, wide and in area, lying a short way off the NW end of Ellsworth Land, Antarctica. It is the third largest island of Antarctica, after Alexander Island and Berkner Island...

 from the Eights Coast of Ellsworth Land

Ellsworth Land

Ellsworth Land is that portion of the Antarctic continent bounded on the west by Marie Byrd Land, on the north by Bellingshausen Sea, on the northeast by the base of Antarctic Peninsula, and on the east by the western margin of Ronne Ice Shelf. It extends between 103°24'W and 79°45'W...

 in Antarctica. The sound is occupied by the western part of the Abbot Ice Shelf

Abbot Ice Shelf

The Abbot Ice Shelf is an ice shelf long and wide, bordering Eights Coast from Cape Waite to Phrogner Point in Antarctica. Thurston Island lies along the northern edge of the western half of this ice shelf; other sizable islands lie partly or wholly within this shelf.The ice shelf was sighted by...

, and is therefore not navigable by ships.

The feature was discovered by members of the USAS

United States Antarctic Program

United States Antarctic Program is an organization of the United States government which has presence in the continent of Antarctica. It co-ordinates research and the operational support for research in the region...

 in flights from the ship Bear in February 1940, and was further delineated from air photos taken by US Navy Operation Highjump

Operation Highjump

Operation Highjump , officially titled The United States Navy Antarctic Developments Program, 1946-1947, was a United States Navy operation organized by RADM Richard E. Byrd Jr. USN, , Officer in Charge, Task Force 68, and led by RADM Richard H. Cruzen, USN, Commanding Officer, Task Force 68....

 in December 1946. The sound was first noted to parallel the entire south coast of Thurston Island, thereby establishing insularity, by the USN Bellingshausen Sea Expedition in February 1960. Named after the sloop of war Peacock in which Captain William L. Hudson

William L. Hudson

Captain William Levereth Hudson, USN was a United States Navy officer in the first half of the 19th century.-Career:Hudson was born 11 May 1794 in Brooklyn...

, in company with the tender Flying Fish

USS Flying Fish (1838)

USS Flying Fish , a schooner, was formerly the New York City pilot boat Independence. Purchased by the United States Navy at New York City on 3 August 1838 and upon joining her squadron in Hampton Roads 12 August 1838 was placed under command of Passed Midshipman S. R. Knox.Assigned as a tender in...

under Lt. William M. Walker, both of the USEE

United States Exploring Expedition

The United States Exploring Expedition was an exploring and surveying expedition of the Pacific Ocean and surrounding lands conducted by the United States from 1838 to 1842. The original appointed commanding officer was Commodore Thomas ap Catesby Jones. The voyage was authorized by Congress in...

, 1838-42, sailed along the edge of the pack ice to the north of Thurston Island for several days in March 1839.