The Getz Ice Shelf is the largest

Antarctic The Antarctic ( or , American English also or ; commonly ) is a polar region around Earth's South Pole, opposite the Arctic region around the North Pole. The Antarctic comprises the continent of Antarctica, the Kerguelen Plateau and other ...

ice shelf An ice shelf is a large floating platform of ice that forms where a glacier or ice sheet flows down to a coastline and onto the ocean surface. Ice shelves are only found in Antarctica, Greenland, Northern Canada, and the Russian Arctic. The b ...

along the SE Pacific-Antarctic coastline, over long and from wide, bordering the Hobbs and Bakutis Coasts of

Marie Byrd Land Marie Byrd Land (MBL) is an unclaimed region of Antarctica. With an area of , it is the largest unclaimed territory on Earth. It was named after the wife of American naval officer Richard E. Byrd, who explored the region in the early 20th centur ...

between the

McDonald Heights The McDonald Heights () are broad, mainly snow-covered heights about long and rising over between Cape Burks and Morris Head on the coast of Marie Byrd Land, Antarctica. The heights are bounded southward by Hull Glacier, Kirkpatrick Glacier and J ...

and

Martin Peninsula Martin Peninsula () is a peninsula about 96 km (60) mi long and 32 km (20 mi) wide that is ice-covered except for a few rock outcrops along its margins, located between Getz Ice Shelf and Dotson Ice Shelf on the coast of Marie Byrd ...

. Several large islands are partially or wholly embedded in the ice shelf, pinning the calving front. Summer temperature and salinity measurements from 1994 to 2010 show the shelf is subject to more changeable oceanic forcing than other Antarctic shelves. Beneath cold surface waters, the

thermocline A thermocline (also known as the thermal layer or the metalimnion in lakes) is a thin but distinct layer in a large body of fluid (e.g. water, as in an ocean or lake; or air, e.g. an atmosphere) in which temperature changes more drastically with ...

was ~200 m shallower in 2007 than in 2000, indicative of shifting access of deep water to the continental shelf and ice shelf base. The calculated area-average basal melt rates was between 1.1 and 4.1 m of ice per year, making Getz the largest source of meltwater to the Southern Ocean. The ice shelf westward of

Siple Island Siple Island is a long snow-covered island lying east of Wrigley Gulf along the Getz Ice Shelf off Bakutis Coast of Marie Byrd Land, Antarctica. Its centre is located at . Its area is and it is dominated by the dormant shield volcano Mount Si ...

was discovered by the

United States Antarctic Service The United States Antarctic Program (or USAP; formerly known as the United States Antarctic Research Program or USARP and the United States Antarctic Service or USAS) is an organization of the United States government which has presence in the A ...

(USAS) in December 1940. The portion eastward of Siple Island was first delineated from air photos taken by U.S. Navy

Operation Highjump Operation HIGHJUMP, officially titled The United States Navy Antarctic Developments Program, 1946–1947, (also called Task Force 68), was a United States Navy (USN) operation to establish the Antarctic research base Little America IV. The opera ...

, 1946–47. The entire feature was mapped by the

United States Geological Survey The United States Geological Survey (USGS), formerly simply known as the Geological Survey, is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, ...

from U.S. Navy air photos of 1962–65. It was named by the USAS (1939–41) for George F. Getz of

Chicago (''City in a Garden''); I Will , image_map = , map_caption = Interactive Map of Chicago , coordinates = , coordinates_footnotes = , subdivision_type = Country , subdivision_name ...

Illinois Illinois ( ) is a U.S. state, state in the Midwestern United States, Midwestern United States. Its largest metropolitan areas include the Chicago metropolitan area, and the Metro East section, of Greater St. Louis. Other smaller metropolita ...

, who helped furnish the seaplane for the expedition. In February 2021, it was reported that the fourteen glaciers forming the shelf had all speeded up, and had lost 315

gigatonnes The tonne ( or ; symbol: t) is a unit of mass equal to 1000 kilograms. It is a non-SI unit accepted for use with SI. It is also referred to as a metric ton to distinguish it from the non-metric units of the short ton (United States c ...

of ice since 1994. The cause of the speed up has been posited as "ocean forcing", a process where relatively warm deep ocean water melts the glaciers from below.

References

Ice shelves of Antarctica Bodies of ice of Marie Byrd Land {{MarieByrdLand-geo-stub

See also

Further reading

References