The Amundsen Sea is an arm of the

Southern Ocean The Southern Ocean, also known as the Antarctic Ocean, comprises the southernmost waters of the world ocean, generally taken to be south of 60th parallel south, 60° S latitude and encircling Antarctica. With a size of , it is the seco ...

off

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 centu ...

in western

Antarctica Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean (also known as the Antarctic Ocean), it contains the geographic South Pole. ...

. It lies between Cape Flying Fish (the northwestern tip of

Thurston Island Thurston Island () is a largely ice-covered, glacially dissected island, long and wide, lying between Amundsen Sea and Bellingshausen Sea a short way off the northwest end of Ellsworth Land, Antarctica. The island is separated from the mainlan ...

) to the east and Cape Dart on Siple Island to the west. Cape Flying Fish marks the boundary between the Amundsen Sea and the Bellingshausen Sea. West of Cape Dart there is no named

marginal sea This is a list of seas of the World Ocean, including marginal seas, areas of water, various gulfs, bights, bays, and straits. In many cases it is a matter of tradition for a body of water to be named a sea or a bay, etc., therefore all these ...

of the

between the Amundsen and Ross Seas. The Norwegian expedition of 1928–1929 under Captain Nils Larsen named the body of water for the Norwegian polar explorer

Roald Amundsen Roald Engelbregt Gravning Amundsen (, ; ; 16 July 1872 – ) was a Norwegians, Norwegian explorer of polar regions. He was a key figure of the period known as the Heroic Age of Antarctic Exploration. Born in Borge, Østfold, Norway, Am ...

while exploring this area in February 1929. The sea is mostly ice-covered, and the Thwaites Ice Tongue protrudes into it. The

ice sheet In glaciology, an ice sheet, also known as a continental glacier, is a mass of glacier, glacial ice that covers surrounding terrain and is greater than . The only current ice sheets are the Antarctic ice sheet and the Greenland ice sheet. Ice s ...

which drains into the Amundsen Sea averages about in thickness; roughly the size of the state of Texas, this area is known as the Amundsen Sea Embayment (ASE); it forms one of the three major ice-drainage basins of the

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

Embayment

The ice sheet that drains into the Amundsen Sea averages about in thickness. It is roughly the size of the state of Texas and is known as the Amundsen Sea Embayment (ASE); it forms one of the three major ice drainage basins of the

along with the

Ross Sea The Ross Sea is a deep bay of the Southern Ocean in Antarctica, between Victoria Land and Marie Byrd Land and within the Ross Embayment, and is the southernmost sea on Earth. It derives its name from the British explorer James Clark Ross who ...

Embayment A bay is a recessed, coastal body of water that directly connects to a larger main body of water, such as an ocean, a lake, or another bay. A large bay is usually called a ''gulf'', ''sea'', ''sound'', or ''bight''. A ''cove'' is a small, ci ...

and the

Weddell Sea The Weddell Sea is part of the Southern Ocean and contains the Weddell Gyre. Its land boundaries are defined by the bay formed from the coasts of Coats Land and the Antarctic Peninsula. The easternmost point is Cape Norvegia at Princess Martha C ...

Embayment. Some scientists proposed that this region may be a weak underbelly of the

. The Pine Island and Thwaites Glaciers, which both flow into the Amundsen Sea, are two of Antarctica's largest five. Researchers reported that the flow of these glaciers increased starting in the mid-2000s; if they were to melt completely, global sea levels would rise by about . Other researchers suggested that the loss of these glaciers would destabilise the entire West Antarctic ice sheet and possibly sections of the

East Antarctic Ice Sheet The East Antarctic Ice Sheet (EAIS) lies between 45th meridian west, 45° west and 168th meridian east, 168° east longitudinally. It was first formed around 34 million years ago, and it is the largest ice sheet on the entire planet, with far gre ...

. A 2004 study suggested that because the ice in the Amundsen Sea had been melting rapidly and was riven with cracks, the offshore ice shelf was set to collapse "within five years". The study projected a sea level rise of from the West Antarctic Ice Sheet if all the sea ice in the Amundsen Sea melted. Measurements made by the

British Antarctic Survey The British Antarctic Survey (BAS) is the United Kingdom's national polar research institute. It has a dual purpose, to conduct polar science, enabling better understanding of list of global issues, global issues, and to provide an active prese ...

in 2005 showed that the ice discharge rate into the Amundsen Sea embayment was about 250 km³ per year. Assuming a steady rate of discharge, this alone was sufficient to raise global sea levels by 0.2 mm per year. A subglacial

volcano A volcano is commonly defined as a vent or fissure in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. On Earth, volcanoes are most oft ...

was detected just north of the Pine Island Glacier near the Hudson Mountains. It last erupted approximately 2,200 years ago, indicated by widespread ash deposits within the ice, in what was the largest known eruption in Antarctica within the prior 10 millennia. Volcanic activity may be contributing to the observed increase of glacial flow, although the most popular theory is that the flow has increased due to warming ocean water. This water has warmed due to an upwelling of deep ocean water due to variations in pressure systems, which could have been affected by

global warming Present-day climate change includes both global warming—the ongoing increase in global average temperature—and its wider effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes ...

In January 2010, a modelling study suggested that the "tipping point" for Pine Island Glacier may have been passed in 1996, with a retreat of possible by 2100, producing a corresponding of

sea level rise The sea level has been rising from the end of the last ice age, which was around 20,000 years ago. Between 1901 and 2018, the average sea level rose by , with an increase of per year since the 1970s. This was faster than the sea level had e ...

. It was suggested that these estimates were conservative. The modelling study also stated that "Given the complex, three-dimensional nature of the real Pine Island glacier ... it should be clear that the ..model is a very crude representation of reality." A 2023 study estimated that the area lost 3.3 trillion tons of ice between 1996 and 2021, raising sea levels by 9 millimeters.

Pine Island Bay

Pine Island Bay () is a bay about long and wide, into which flows the ice of the Pine Island Glacier at the southeast extremity of the Amundsen Sea. It was delineated from aerial photographs taken by United States Navy (USN)

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 (exploration b ...

in December 1946, and named by the

Advisory Committee on Antarctic Names The Advisory Committee on Antarctic Names (ACAN or US-ACAN) is an advisory committee of the United States Board on Geographic Names responsible for recommending commemorative names for features in Antarctica. History The committee was established ...

for the USS ''Pine Island'', seaplane tender and flagship of the eastern task group of USN Operation HIGHJUMP which explored this area.

Russell Bay

Russell Bay () is a rather open bay in southwestern Amundsen Sea, extending along the north sides of Siple Island, Getz Ice Shelf and Carney Island, from Pranke Island to Cape Gates. It was mapped by the

United States Geological Survey The United States Geological Survey (USGS), founded as the Geological Survey, is an agency of the U.S. Department of the Interior whose work spans the disciplines of biology, geography, geology, and hydrology. The agency was founded on Mar ...

from surveys and USN air photos, 1959–66, and named by the

for Admiral James S. Russell,

Vice Chief of Naval Operations The vice chief of naval operations (VCNO) is the second highest-ranking commissioned United States Navy officer and functions as the principal deputy of the Chief of Naval Operations, chief of naval operations. By statute, the vice chief is appo ...

during the post 1957–58 IGY period.

Climate engineering

References

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External links

Airborne Geophysical Survey of the Amundsen Embayment

Thinning ice
{{Authority control Seas of the Southern Ocean