Gilbert Glacier is a glacier

Glacier

A glacier is a large persistent body of ice that forms where the accumulation of snow exceeds its ablation over many years, often centuries. At least 0.1 km² in area and 50 m thick, but often much larger, a glacier slowly deforms and flows due to stresses induced by its weight...

 about 20 nautical miles (37 km) long flowing south from Nichols Snowfield

Nichols Snowfield

Nichols Snowfield is a snowfield, 22 nautical miles long and 8 nautical miles wide, bounded by the Rouen Mountains and Elgar Uplands to the east and Lassus Mountains to the west, in the north part of Alexander Island. First seen from the air and roughly mapped by the British Graham Land...

 into Mozart Ice Piedmont

Mozart Ice Piedmont

Mozart Ice Piedmont is an ice piedmont, 60 nautical miles long in a NW-SE direction and 15 nautical miles wide in its widest part, on the west coast of Alexander Island. Mapped from air photos taken by the Ronne Antarctic Research Expedition in 1947, by Searle of the Falkland Islands...

, Alexander Island

Alexander Island

Alexander Island or Alexander I Island or Alexander I Land or Alexander Land is the largest island of Antarctica, with an area of lying in the Bellingshausen Sea west of the base of the Antarctic Peninsula, from which it is separated by Marguerite Bay and George VI Sound. Alexander Island lies off...

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Photographed from the air by Ronne Antarctic Research Expedition

Ronne Antarctic Research Expedition

The Ronne Antarctic Research Expedition was an expedition from 1947-1948 which researched the area surrounding the head of the Weddell Sea in Antarctica.-Background:...

 (RARE), 1947–48, and mapped from these photographs by D. Searle of Falkland Islands Dependencies Survey (FIDS), 1960. Named in association with Sullivan Glacier

Sullivan Glacier

Sullivan Glacier is a glacier flowing west into Gilbert Glacier, immediately south of Elgar Uplands in the north part of Alexander Island. First seen from a distance by the British Graham Land Expedition during a flight in 1937 and roughly mapped...

, after Sir William S. Gilbert (1836–1911), British librettist. Named by United Kingdom Antarctic Place-Names Committee (UK-APC), 1977.