Cassidy 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...

 7 miles (11.3 km) long and 2 miles (3 km) wide, flowing northeast into upper Taylor Glacier

Taylor Glacier

The Taylor Glacier is an Antarctic glacier about long, flowing from the plateau of Victoria Land into the western end of Taylor Valley, north of the Kukri Hills, south of the Asgard Range...

 between Depot Nunatak

Depot Nunatak

Depot Nunatak is a nunatak, 1,980 m, standing at the west side of Cassidy Glacier and Quartermain Mountains in Victoria Land. Nearly vertical cliffs of columnar dolerite rise 150 m above glacier level at the east end. So named by the Discovery expedition , on their western journey in 1903, because...

 and the northwest end of the Quartermain Mountains

Quartermain Mountains

Quartermain Mountains is a group of exposed mountains, about 20 miles long, typical of ice-free features of the McMurdo Dry Valleys, Victoria Land, located south of Taylor Glacier and bounded by Finger Mountain, Mount Handsley, Mount Feather and Tabular Mountain; also including Knobhead, Terra...

, in Victoria Land

Victoria Land

Victoria Land is a region of Antarctica bounded on the east by the Ross Ice Shelf and the Ross Sea and on the west by Oates Land and Wilkes Land. It was discovered by Captain James Clark Ross in January 1841 and named after the UK's Queen Victoria...

. The descriptive names "South-West Arm" and "South Arm" were applied to this glacier and to the part of Ferrar Glacier

Ferrar Glacier

The Ferrar Glacier is an Antarctic glacier about long, flowing from the plateau of Victoria Land west of the Royal Society Range to New Harbour in McMurdo Sound. The glacier makes a right turn northeast of Knobhead, where it is apposed, i.e., joined in Siamese-twin fashion, to Taylor Glacier...

 south of Knobhead

Knobhead

Knobhead is a massive ice-free mountain, 2,400 m, standing south of the west end of Kukri Hills and overlooking the Ferrar and Taylor Glaciers at their point of apposition, in Victoria Land. It was discovered by the Discovery expedition and so named because of its appearance....

, respectively, by the British National Antarctic Expedition, 1901–04. Subsequent mapping has shown that the glacier described here is part of the Taylor Glacier system.

The glacier was 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...

 in 1992 after William A. Cassidy, Department of Geology and Planetary Science, University of Pittsburgh

University of Pittsburgh

The University of Pittsburgh, commonly referred to as Pitt, is a state-related research university located in Pittsburgh, Pennsylvania, United States. Founded as Pittsburgh Academy in 1787 on what was then the American frontier, Pitt is one of the oldest continuously chartered institutions of...

, who in 13 field seasons, 1976–90, led United States Antarctic Research Program teams in the investigation and collection of Antarctic meteorites from diverse sites through Victoria Land and southward to Lewis Cliff

Lewis Cliff

Lewis Cliff is an irregular cliff, about 12 nautical miles long, extending south from Mount Achernar along the west side of Walcott Neve. Named by Advisory Committee on Antarctic Names for Richard E. Lewis, Aviation Electronics Technician, U.S. Navy, who was injured during U.S. Navy Operation...

, adjacent to the Queen Alexandra Range

Queen Alexandra Range

The Queen Alexandra Range is a major mountain range in East Antarctica, about 160 km long, bordering the entire western side of Beardmore Glacier from the Polar Plateau to the Ross Ice Shelf. Alternate names for this range include Alexandra Mountains, Alexandra Range and Königin Alexandra...

.