Amundsen Glacier

Amundsen Glacier is a major glacier in Marie Byrd Land, Antarctica. It flows from the Queen Maud Mountains to the Ross Ice Shelf between the Lillie Range and the Hays Mountains. The glacier was discovered and named in honor of the famed Norwegian polar explorer Roald Amundsen, who led the first expedition to reach the South Pole.

Geography and location

The Amundsen Glacier originates on the vast Polar Plateau near the Dominion Range and flows northward through a deep, glacially carved valley. It is situated between the Lillie Range to the west and the Hays Mountains, part of the Queen Maud Mountains, to the east. Its terminus feeds into the northwestern sector of the Ross Ice Shelf, a massive floating ice platform bordering the Ross Sea. Key nearby features include the Scott Glacier to the west and the Liv Glacier to the east, all of which are major outlets from the East Antarctic Ice Sheet. The surrounding region is characterized by the Transantarctic Mountains, which form a formidable barrier between the continental interior and the Ross Sea.

Discovery and naming

The glacier was discovered in November 1929 by members of the Byrd Antarctic Expedition, led by Admiral Richard E. Byrd. During a historic flight from the expedition's base at Little America, Bernt Balchen, the pilot, and Harold June, the radioman, observed and photographed this major ice stream. The United States Antarctic Service officially named it for Roald Amundsen in recognition of his monumental achievements in polar exploration, which included the first navigation of the Northwest Passage and his triumphant arrival at the South Pole in December 1911 during the *Fram* Expedition. The naming was part of a tradition honoring great explorers of the Heroic Age of Antarctic Exploration.

Physical characteristics

The Amundsen Glacier is approximately 128 kilometers long and averages 10 kilometers in width, making it one of the significant outlet glaciers draining the West Antarctic Ice Sheet. It features a heavily crevassed surface, especially where it descends from the high plateau through the Transantarctic Mountains. The glacier's flow rate is measured in meters per year, and it exhibits a typical pattern of faster flow in its central trunk. Its ice thickness is substantial, contributing to the mass balance of the Ross Ice Shelf. The glacier's bed topography, studied through radar surveys by organizations like the British Antarctic Survey and the United States Geological Survey, reveals a deep subglacial trench, influencing its dynamics and potential sensitivity to climate change.

Scientific importance

The Amundsen Glacier is a critical site for research into ice sheet dynamics and sea level rise. Scientists from institutions like the National Science Foundation's United States Antarctic Program and the Scott Polar Research Institute conduct regular field campaigns there. Research focuses on measuring ice velocity using satellite imagery from NASA and the European Space Agency, assessing mass balance, and drilling ice cores to reconstruct past climate. Its behavior is closely monitored because changes in its flow could impact the stability of the wider West Antarctic Ice Sheet. The region is also a natural laboratory for studying extreme microbiology and geology, with researchers from the Alfred Wegener Institute and the Australian Antarctic Division investigating subglacial environments.

Tributaries and flow

The primary flow of the Amundsen Glacier is fed by several major tributaries converging from the Polar Plateau and the surrounding highlands. Significant contributory ice streams include the Siple Coast ice streams to the west and inputs from the Support Force Glacier system. The glacier's flow is channeled by the subglacial topography beneath the Queen Maud Mountains, accelerating as it approaches the Ross Ice Shelf. Its interaction with the shelf creates a dynamic grounding line, an area of intense study by projects like the International Thwaites Glacier Collaboration. The glacier ultimately calves icebergs into the Ross Sea, contributing to the mass balance of the Southern Ocean and global ocean circulation patterns studied by the Intergovernmental Panel on Climate Change. Category:Glaciers of Marie Byrd Land Category:Queen Maud Mountains