Lambert Glacier

Lambert Glacier. It is the world's largest glacier and a major ice stream that drains a significant portion of the East Antarctic Ice Sheet. Flowing from the Prince Charles Mountains to the Amery Ice Shelf, it is a critical component of the Antarctic cryosphere. Its immense scale and dynamics make it a primary focus for studies of ice sheet stability and global sea level rise.

Overview

This immense feature is a principal outlet for the East Antarctic Ice Sheet, channeling ice from the vast interior plateau towards the coast. It merges with the Fisher Glacier and other tributaries before feeding into the floating Amery Ice Shelf in Mac. Robertson Land. The glacier's catchment area encompasses a substantial portion of the continental interior, making its behavior vital for understanding the mass balance of Antarctica. Its flow is monitored by international programs like those of the British Antarctic Survey and the Australian Antarctic Division.

Physical characteristics

The main trunk exceeds 400 kilometers in length and reaches widths of nearly 100 kilometers, with ice thicknesses surpassing 2,500 meters in places. It is classified as an ice stream, characterized by rapid, channelized flow within slower-moving ice. The underlying bedrock topography, studied via radio-echo sounding, reveals deep subglacial trenches that guide its flow. The glacier's velocity increases from a few meters per year near the Gamburtsev Mountain Range to hundreds of meters annually as it approaches the Amery Ice Shelf. Distinct surface features include extensive crevasse fields and shear margins.

Discovery and exploration

The glacier was first identified from aerial photographs taken during Operation Highjump in 1946–1947. It was named in 1952 by the Australian National Antarctic Research Expeditions (ANARE) for Bruce P. Lambert, the Director of National Mapping. Detailed mapping and study were advanced by the Soviet Antarctic Expedition and later overland traverses. The International Geophysical Year spurred significant research, with subsequent major investigations conducted from stations like Mawson Station and Davis Station.

Role in the Antarctic ice sheet

As a primary drainage pathway, it is integral to the mass balance and stability of the East Antarctic Ice Sheet. It discharges approximately 35 billion tonnes of ice into the Amery Ice Shelf each year, which in turn loses mass through basal melt and calving of icebergs into the Southern Ocean. This system acts as a regulator for the inland ice, with changes in its flow speed or the stability of the Amery Ice Shelf having direct implications for global sea level rise. Its dynamics are influenced by interactions with the Southern Ocean and climate change.

Scientific research and importance

Long-term monitoring of its flow velocity and mass balance is conducted using satellite remote sensing from missions like NASA's ICESat and the European Space Agency's CryoSat-2. Research focuses on understanding its sensitivity to ocean forcing and atmospheric warming, which are critical for improving projections in reports by the Intergovernmental Panel on Climate Change. The glacier also provides a record of past climate through deep ice core drilling projects. Ongoing international efforts, involving institutions like the Scripps Institution of Oceanography and the Alfred Wegener Institute, aim to reduce uncertainties in future sea level forecasts. Category:Glaciers of Antarctica Category:Mac. Robertson Land