Totten Glacier is a large

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 over many years, often centuries. It acquires distinguishing features, such as ...

draining a major portion of the

East Antarctic Ice Sheet The East Antarctic Ice Sheet (EAIS) is one of two large ice sheets in Antarctica, and the largest on the entire planet. The EAIS lies between 45° west and 168° east longitudinally. The EAIS holds enough ice to raise global sea levels by and ...

, through the

Budd Coast Budd Coast (), part of Wilkes Land, is that portion of the coast of Antarctica lying between the Hatch Islands, at 109°16'E, and Cape Waldron, at 115°33'E. It was discovered in February 1840 by the U.S. Exploring Expedition (1838–42) under t ...

Wilkes Land Wilkes Land is a large district of land in eastern Antarctica, formally claimed by Australia as part of the Australian Antarctic Territory, though the validity of this claim has been placed for the period of the operation of the Antarctic Treaty ...

in the Australian Antarctic Territory. The catchment drained by the glacier is estimated at , extending approximately into the interior and holds the potential to raise sea level by at least . Totten drains northeastward from the continental ice but turns northwestward at the coast where it terminates in a prominent tongue close east of

Cape Waldron Cape Waldron () is an ice-covered cape in Antarctica, just westward of Totten Glacier. It was delineated by G.D. Blodgett (1955) from aerial photographs taken by USN Operation Highjump (1946–47), and named by the Advisory Committee on Antarcti ...

. It was first delineated from aerial photographs taken by USN Operation Highjump (1946–47), and named by Advisory Committee on Antarctic Names (US-ACAN) for George M. Totten, midshipman on of the

United States Exploring Expedition The United States Exploring Expedition of 1838–1842 was an exploring and surveying expedition of the Pacific Ocean and surrounding lands conducted by the United States. The original appointed commanding officer was Commodore Thomas ap Catesby ...

(1838–42), who assisted Lieutenant

Charles Wilkes Charles Wilkes (April 3, 1798 – February 8, 1877) was an American naval officer, ship's captain, and explorer. He led the United States Exploring Expedition (1838–1842). During the American Civil War (1861–1865), he commanded ' during the ...

with correction of the survey data obtained by the expedition. Totten Ice Shelf is a floating portion of Totten Glacier, laterally bounded by the Aurora Subglacial Basin to the south and

Law Dome Law Dome is a large ice dome which rises to directly south of Cape Poinsett, Antarctica. The feature was roughly mapped by the United States Geological Survey from aerial photographs taken by U.S. Navy Operation Highjump, 1946–47, and has been ...

to the north. The ice shelf exists at the confluence of the two main grounded tributaries of Totten Glacier, its base lies below sea level near the grounding line of the western tributary, and the ice shelf surface is characterized by longitudinal channels and transverse fractures. Totten Ice Shelf is of glaciological interest because it buttresses the flow of grounded ice while coupling the ice basin to ocean processes such as ocean warming. Totten Glacier Tongue () is a small

tongue extending seaward from Totten Glacier. Delineated from air photos taken by U.S. Navy Operation Highjump (1946–47) and named by US-ACAN in association with Totten Glacier.

Melt

Totten Glacier drains the Aurora Subglacial Basin, which is largely grounded below sea level and is subject to

marine ice sheet instability Marine ice sheet instability (MISI) describes the potential for ice sheets grounded below sea level to destabilize in a runaway fashion. The mechanism was first proposed in the 1970s by Johannes Weertman and was quickly identified as a means by whi ...

, meaning melt near the

grounding line Marine ice sheet instability (MISI) describes the potential for ice sheets grounded below sea level to destabilize in a runaway fashion. The mechanism was first proposed in the 1970s by Johannes Weertman and was quickly identified as a means by wh ...

could lead to runaway glacier retreat and a significant contribution to sea level rise. Surface altimetry measurements from

Interferometric synthetic-aperture radar Interferometric synthetic aperture radar, abbreviated InSAR (or deprecated IfSAR), is a radar technique used in geodesy and remote sensing. This geodetic method uses two or more synthetic aperture radar (SAR) images to generate maps of surface defor ...

suggest that Totten Glacier lost mass from 1992 to 2006 and gravity measurements obtained by the

Gravity Recovery and Climate Experiment The Gravity Recovery and Climate Experiment (GRACE) was a joint mission of NASA and the German Aerospace Center (DLR). Twin satellites took detailed measurements of Earth's gravity field anomalies from its launch in March 2002 to the end of its ...

satellite indicate mass loss has continued through at least 2016. The

ICESat ICESat (Ice, Cloud, and land Elevation Satellite) was a NASA satellite mission for measuring ice sheet mass balance, cloud and aerosol heights, as well as land topography and vegetation characteristics. It operated as part of NASA's Earth Obs ...

laser altimeter measured surface lowering of the grounded and floating portions of Totten Glacier from 2003 to 2009; however, longer term observations of the floating ice shelf show interannual variability of thickness and velocity. Totten Glacier loses mass primarily through melt at its ice shelf base, and melt is influenced by the availability of ocean heat entering the cavity below the ice shelf. Warm, modified

Circumpolar deep water Circumpolar Deep Water (CDW) is a designation given to the water mass in the Pacific and Indian oceans that is a mixing of other water masses in the region. It is characteristically warmer and saltier than the surrounding water masses, causing CD ...

enters the Totten Ice Shelf cavity through submarine canyons, driven by wind processes at the nearby continental shelf break. Wind processes and sea ice formation along the

Sabrina Coast Sabrina Coast () is that portion of the coast of Wilkes Land, Antarctica, lying between Cape Waldron, at 115° 33' E, and Cape Southard, at 122° 05' E. John Balleny has long been credited with having seen land in March 1839 at about 117° E. T ...

have been linked to variability in Totten Ice Shelf basal melt and calving rates.

References

{{Glaciers of Wilkes Land Ice streams of Antarctica Glaciers of Wilkes Land

Melt

See also

References