Denman Glacier is a

glacier A glacier (; ) is a persistent body of dense ice that is constantly moving under its own weight. A glacier forms where the accumulation of snow exceeds its Ablation#Glaciology, ablation over many years, often Century, centuries. It acquires dis ...

wide, descending north some , which

debouches In hydrology, a debouch (or debouche) is a place where runoff from a small, confined space discharges into a larger, broader body of water. The word is derived from the French verb ''déboucher'' (), which means "to unblock, to clear". The term ...

into the

Shackleton Ice Shelf Shackleton Ice Shelf is an extensive ice shelf fronting the coast of East Antarctica from 95° E to 105° E. It extends for an along-shore distance of about , projecting seaward about in the western portion and in the east. It occu ...

east of David Island,

Queen Mary Land Queen Mary Land or the Queen Mary Coast () is the portion of the coast of Antarctica lying between Cape Filchner, in 91° 54' E, and Cape Hordern, at 100° 30' E. It is claimed by Australia as part of the Australian Antarctic Territory. It w ...

. It was discovered in November 1912 by the

Western Base party The Western Base Party was a successful exploration party of the Australasian Antarctic Expedition. The eight-man Western Party was deposited by the SY ''Aurora'' on the Shackleton Ice Shelf at Queen Mary Land. The leader of the team was Fran ...

of the

Australasian Antarctic Expedition The Australasian Antarctic Expedition was a 1911–1914 expedition headed by Douglas Mawson that explored the largely uncharted Antarctic coast due south of Australia. Mawson had been inspired to lead his own venture by his experiences on Ernest ...

under

Sir Douglas Mawson Sir Douglas Mawson OBE FRS FAA (5 May 1882 – 14 October 1958) was an Australian geologist, Antarctic explorer, and academic. Along with Roald Amundsen, Robert Falcon Scott, and Sir Ernest Shackleton, he was a key expedition leader durin ...

. Mawson named the glacier for Lord Denman,

Governor-General of Australia The governor-general of Australia is the representative of the monarch, currently King Charles III, in Australia.University of California, Irvine The University of California, Irvine (UCI or UC Irvine) is a public land-grant research university in Irvine, California. One of the ten campuses of the University of California system, UCI offers 87 undergraduate degrees and 129 graduate and pr ...

) to be the deepest natural location on land (or at least not under liquid water) worldwide, with the bedrock being below sea level. Calving of Denman Glacier into the

Mawson Sea Mawson Sea is a proposed sea name along the Queen Mary Land coast of East Antarctica east of the Shackleton Ice Shelf. West of it, on the western side of Shackleton Ice Shelf, would be the Davis Sea. To the east would be Bowman Island and Vince ...

gives rise to the periodically appearing

Pobeda Ice Island Pobeda Ice Island, original Russian name остров Победы (остров = ''Island'', Победа = ''Victory'', meaning Pobeda Island or Victory Island), is an ''ice island'' in the Mawson Sea. It is located off the coast of Queen Ma ...

Instability and retreat

A 2020 study reported Denman Glacier has retreated 5.4±0.3 km over a 20-year-period from 1996 to 2017–2018. The study projects that the glacier has the potential to undergo a rapid, irreversible retreat, due to the presence of a retrograde bed on the western flank of the glacier and the likely presence of warm water in the sub-ice-shelf cavity. If the entirety of the glacier were hollowed out, it would contribute to a 1.5 m rise in global sea level. However, as there are many factors which will determine the rate of retreat as it continues, such as the narrowness of the channel along which it is occurring and the movement of warm water from the deep ocean, it is difficult to be certain about the fate of the glacier without the collection of more data. Shape of bedrock under Denman Glacier

Denman represents one of relatively few ice streams that have been identified as requiring special attention in

East Antarctica East Antarctica, also called Greater Antarctica, constitutes the majority (two-thirds) of the Antarctic continent, lying on the Indian Ocean side of the continent, separated from West Antarctica by the Transantarctic Mountains. It lies almost ...

, which has generally been thought of as stable compared to the

West Antarctic Ice Sheet The Western Antarctic Ice Sheet (WAIS) is the segment of the continental ice sheet that covers West Antarctica, the portion of Antarctica on the side of the Transantarctic Mountains that lies in the Western Hemisphere. The WAIS is classified as ...

. Findings of the instability and retreat of Denman Glacier have contributed to a shift in the perception of change in East Antarctica, along with changes observed at

Totten Glacier Totten Glacier is a large glacier draining a major portion of the East Antarctic Ice Sheet, through the Budd Coast of Wilkes Land in the Australian Antarctic Territory. The catchment drained by the glacier is estimated at , extending approximate ...

and glaciers at

Vincennes Bay Vincennes Bay is a large V-shaped bay, 105 km (65 mi) wide at its entrance between Cape Nutt and Cape Folger in Antarctica, marked by several large, steep glaciers near its head, lying along Knox and Budd Coasts. It was photographed f ...

, Porpoise Bay, and the

George V Coast George V Coast () is that portion of the coast of Antarctica lying between Point Alden, at 148°2′E, and Cape Hudson, at 153°45′E. Portions of this coast were sighted by the US Exploring Expedition in 1840. It was explored by members of t ...

References

Ice streams of Antarctica Glaciers of Queen Mary Land {{Antarctica-glacier-stub

Instability and retreat

See also

References