Sibelius 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...

, 12 miles (19 km) long and 6 miles (10 km) wide, flowing south 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...

 10 miles (16 km) southwest of Mount Stephenson

Mount Stephenson

Mount Stephenson a mountain in Antarctica. It is located in the Douglas Range, standing at the heads of Toynbee Glacier and Sedgwick Glacier 8 miles west of George VI Sound, on the east side of Alexander Island within the British Antarctic Territory...

 in the north part of 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...

. First seen from the air by the British Graham Land Expedition

British Graham Land Expedition

A British expedition to Graham Land led by John Lachlan Cope took place between 1920 and 1922. The British Graham Land Expedition was a geophysical and exploration expedition to Graham Land in Antarctica between 1934 to 1937. Under the leadership of John Riddoch Rymill, the expedition spent two...

 (BGLE) in 1937. Mapped from air photos taken by the 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, by Searle of the Falkland Islands Dependencies Survey (FIDS) in 1960. Named by the United Kingdom Antarctic Place-Names Committee (UK-APC) for Jean Sibelius

Jean Sibelius

Jean Sibelius was a Finnish composer of the later Romantic period whose music played an important role in the formation of the Finnish national identity. His mastery of the orchestra has been described as "prodigious."...

(1865-1957), Finnish composer.