![Antarctic Sea Ice_-_Amundsen Sea](https://upload.wikimedia.org/wikipedia/commons/0/06/Antarctic_Sea_Ice_-_Amundsen_Sea.jpg)
The Amundsen Sea, 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 60° S latitude and encircling Antarctica. With a size of , it is regarded as the second-small ...
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 centur ...
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, it contains the geographic South Pole. Antarctica is the fifth-largest contine ...
, lies between
Cape Flying Fish
Cape Flying Fish (, also known as Cape Dart) is an ice-covered cape which forms the western extremity of Thurston Island. It was discovered by Richard E. Byrd and members of the US Antarctic Program in a flight from the USS ''Bear'' in Februa ...
(the northwestern tip of
Thurston Island
Thurston Island is an ice-covered, glacially dissected island, long, wide and in area, lying a short way off the northwest end of Ellsworth Land, Antarctica. It is the third-largest island of Antarctica, after Alexander Island and Berkner Isl ...
) to the east and
Cape Dart
Cape Dart () is a cape at the foot of Mount Siple on the north coast of Siple Island, just southward of Lauff Island off the Bakutis Coast, Marie Byrd Land. It was discovered in December 1940 by members of the United States Antarctic Service
...
on
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 ...
to the west. Cape Flying Fish marks the boundary between the Amundsen Sea and the
Bellingshausen Sea
The Bellingshausen Sea is an area along the west side of the Antarctic Peninsula between 57°18'W and 102°20'W, west of Alexander Island, east of Cape Flying Fish on Thurston Island, and south of Peter I Island (there the southern ''Vostokkyste ...
. 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.
Terminology
* Ocean – the four to seven largest named bodies of water in the World Ocean, all of which have "Ocean ...
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 60° S latitude and encircling Antarctica. With a size of , it is regarded as the second-small ...
between the Amundsen and
Ross Ross or ROSS may refer to:
People
* Clan Ross, a Highland Scottish clan
* Ross (name), including a list of people with the surname or given name Ross, as well as the meaning
* Earl of Ross, a peerage of Scotland
Places
* RoSS, the Republic of Sou ...
Seas. The Norwegian expedition of 1928–1929 under Captain
Nils Larsen
Nils Larsen (19 June 1900 – 29 September 1976) was a Norwegian sea captain. Larsen is perhaps most associated with the Norvegia expeditions of Antarctica.
Larsen was born in Sandar, and became a noted whaler, captaining a number of whali ...
named the body of water for the Norwegian polar explorer
Roald Amundsen
Roald Engelbregt Gravning Amundsen (, ; ; 16 July 1872 – ) was a 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, Amundsen bega ...
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 glacial ice that covers surrounding terrain and is greater than . The only current ice sheets are in Antarctica and Greenland; during the Last Glacial Period at Las ...
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 Western 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. The WAI ...
.
Embayment
![Amundsen Sea Icebergs](https://upload.wikimedia.org/wikipedia/commons/0/0a/Amundsen_Sea_Icebergs.jpg)
The ice sheet which drains into the Amundsen Sea averages about in thickness; is roughly the size of the state of Texas and the 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 Western 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. The WAI ...
, the others being 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 vi ...
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, circular bay with a narr ...
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 ...
Embayment. In March 2007, scientists studying the ASE through satellite and airborne surveys announced a significant thinning of the ASE, due to shifts in wind patterns that allow warmer waters to flow beneath the ice sheet.
Some scientists have proposed that this region may be a "weak underbelly" of the
West Antarctic Ice Sheet
The Western 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. The WAI ...
. The
Pine Island and
Thwaites Glaciers, which both flow into the Amundsen Sea, are two of Antarctica's largest five. Scientists have found that the flow of these glaciers has increased starting in the mid-2000s decade; if they were to melt completely, global sea levels would
rise
Rise or RISE may refer to:
Arts, entertainment, and media Fictional entities
* '' Rise: The Vieneo Province'', an internet-based virtual world
* Rise FM, a fictional radio station in the video game ''Grand Theft Auto 3''
* Rise Kujikawa, a vide ...
by about . Scientist have 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) 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 ...
.
A study in October 2004 suggested that because the ice in the Amundsen Sea had been melting rapidly and 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 global issues, and to provide an active presence in the Antarctic on ...
in 2005 showed that the ice discharge rate into the Amundsen Sea embayment was about 250 km
3 per year. Assuming a steady rate of discharge, this alone is sufficient to raise global sea levels by 0.2 mm per year.
A subglacial
volcano
A volcano is a rupture 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 often found where tectonic plates are ...
has also been detected in the area, just north of the Pine Island Glacier near the
Hudson Mountains
The Hudson Mountains are a mountain range in western Ellsworth Land just east of Cranton Bay and Pine Island Bay at the eastern extremity of Amundsen Sea. They are of volcanic origin, consisting of low scattered mountains and nunataks that prot ...
. It last erupted approximately 2,200 years ago, indicated by widespread
ash
Ash or ashes are the solid remnants of fires. Specifically, ''ash'' refers to all non-aqueous, non- gaseous residues that remain after something burns. In analytical chemistry, to analyse the mineral and metal content of chemical samples, ash ...
deposits within the ice, in what was the largest known eruption in Antarctica within the past 10 millennia.
Volcanic activity in the region may be contributing to the observed increase of glacial flow,
although currently the most popular theory amongst the scientists studying this area is that the flow has increased due to
warming ocean water.
This water has warmed due to an upwelling of deep ocean water which is due to variations in pressure systems, which could have been affected by
global warming
In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to E ...
.
![Antarctic-seas-en](https://upload.wikimedia.org/wikipedia/commons/3/3f/Antarctic-seas-en.svg)
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
Globally, sea levels are rising due to human-caused climate change. Between 1901 and 2018, the globally averaged sea level rose by , or 1–2 mm per year on average.IPCC, 2019Summary for Policymakers InIPCC Special Report on the Ocean and Cry ...
, although it was suggested that these estimates for timespan were conservative.
However, the modelling study also states 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."
Pine Island Bay
Pine Island Bay () is a bay about long and wide, into which flows the ice of the
Pine Island Glacier
Pine Island Glacier (PIG) is a large ice stream, and the fastest melting glacier in Antarctica, responsible for about 25% of Antarctica's ice loss. The glacier ice streams flow west-northwest along the south side of the Hudson Mountains into Pine ...
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 IV. The opera ...
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
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 ...
,
Getz Ice Shelf
The Getz Ice Shelf is the largest Antarctic ice shelf along the SE Pacific-Antarctic coastline, over long and from wide, bordering the Hobbs and Bakutis Coasts of Marie Byrd Land between the McDonald Heights and Martin Peninsula. Several lar ...
and
Carney Island
Carney Island () is an ice-covered island, long and about in area, with all but its North coast lying within the Getz Ice Shelf, Antarctica. It is located between Siple Island and Wright Island along the coast of
Marie Byrd Land.
Carney Is ...
, from
Pranke Island to
Cape Gates Cape Gates () is an ice-covered cape which marks the northwestern extremity of Carney Island along the coast of Marie Byrd Land, Antarctica. It was first mapped by United States Geological Survey from aerial photographs taken by U.S. Navy Operation ...
. It 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 surveys and USN air photos, 1959–66, 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 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 in the Department of the Navy and functions as the principal deputy of the chief of naval operations and by statute, the vice chief ...
during the post 1957–58 IGY period.
References
*
*
External links
Airborne Geophysical Survey of the Amundsen EmbaymentThinning ice
{{Authority control
Seas of the Southern Ocean