Lyddan Island is an ice-covered island at the southwest extremity of Riiser-Larsen Ice Shelf

Riiser-Larsen Ice Shelf

Riiser-Larsen Ice Shelf is an ice shelf about 250 miles long on the coast of Queen Maud Land, extending from Cape Norvegia in the north to Lyddan Island and Stancomb-Wills Glacier in the south. Parts of the ice shelf were sighted by William Speirs Bruce in 1904, Ernest Shackleton in 1915, and...

, separating it from Brunt Ice Shelf

Brunt Ice Shelf

The Brunt Ice Shelf borders the Antarctic coast of Coats Land between Dawson-Lambton Glacier and Stancomb-Wills Glacier Tongue. It was the location of the base of the Royal Society Expedition, 1955–59 which was taken over as the British Halley Research Station...

, about 20 miles off the Princess Martha Coast

Princess Martha Coast

Princess Martha Coast is that portion of the coast of Queen Maud Land lying between 05° E and the terminus of Stancomb-Wills Glacier, at 20° W. The entire coastline is bounded by ice shelves with ice cliffs 20 to 35 m high....

. The island is about 45 miles long and has three narrow arms in the form of a trefoil. It was discovered and plotted by W.R. MacDonald on November 5, 1967, in the course of a USN Squadron VXE-6

VXE-6

VXE-6, Antarctic Development Squadron 6 , commonly referred to by its nickname, The Puckered Penguins was a United States Navy Air Test and Evaluation Squadron based at McMurdo Station, Antarctica...

 reconnaissance flight over the coast in LC-130 aircraft. Named by the Advisory Committee on Antarctic Names

Advisory Committee on Antarctic Names

The Advisory Committee on Antarctic Names is an advisory committee of the United States Board on Geographic Names responsible for recommending names for features in Antarctica...

 (US-ACAN) for Robert H. Lyddan, Chief Topographic Engineer of the United States Geological Survey

United States Geological Survey

The United States Geological Survey is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, and the natural hazards that threaten it. The organization has four major science disciplines, concerning biology,...

(USGS), who has been active in the planning and supervision of Antarctic mapping operations since the 1950s.