Totten Glacier

Totten Glacier. Located in East Antarctica, it is one of the continent's largest and most significant glaciers, flowing from the vast East Antarctic Ice Sheet into the Southern Ocean. Its stability is a critical focus for glaciology and climate science, as it holds enough ice to raise global sea level by several meters. The glacier is named for Captain George Totten of the United States Exploring Expedition led by Charles Wilkes.

Overview

The glacier is a major outlet for the Aurora Subglacial Basin, a region of the East Antarctic Ice Sheet that rests on bedrock far below sea level. This configuration makes it potentially vulnerable to incursions of warm ocean currents. Scientific interest intensified following observations by missions like NASA's Operation IceBridge and data from the ICESat satellite, which indicated dynamic thinning. Its behavior is considered a key indicator for the stability of the wider East Antarctic Ice Sheet, which was long thought to be more stable than the West Antarctic Ice Sheet.

Physical characteristics

The glacier is approximately 120 kilometers long and 30 kilometers wide, with an ice thickness exceeding 2.5 kilometers in its interior. It terminates in the floating Totten Ice Shelf, which is stabilized by pinning points on the Sabrina Coast seabed. The underlying geology, studied by expeditions like the International Ocean Discovery Program, reveals a deep, retrograde bed slope that deepens inland. This topography, similar to that observed beneath Thwaites Glacier, can facilitate rapid and potentially irreversible retreat through a mechanism known as marine ice sheet instability.

Climate change impact

Research published in journals like *Nature* and *Science* has shown the glacier is losing mass due to basal melt driven by modified Circumpolar Deep Water reaching its grounding line. This warm water intrusion is influenced by changes in atmospheric circulation linked to the Southern Annular Mode and the El Niño–Southern Oscillation. Comparative studies with Pine Island Glacier highlight the role of ocean heat in accelerating ice loss. Projections from models like those used by the Intergovernmental Panel on Climate Change suggest its contribution to sea level rise could be substantial over coming centuries.

Research and exploration

Key investigations have been conducted by the Australian Antarctic Division, Scripps Institution of Oceanography, and the University of Texas at Austin. The ITASE project provided early ice core data, while more recent campaigns, such as those aboard the RV *Aurora Australis*, have used autonomous underwater vehicles to map the cavity beneath the ice shelf. International collaborations, including work by the British Antarctic Survey and Japan's National Institute of Polar Research, continue to monitor its dynamics using satellite altimetry from the European Space Agency's CryoSat-2.

Significance and implications

Its potential destabilization represents one of the largest uncertainties in future sea level rise projections, with implications for coastal cities worldwide. The processes observed here are informing global climate models and international assessments like those of the Intergovernmental Panel on Climate Change. Understanding the glacier's interaction with the Southern Ocean is a priority for major scientific programs such as SCAR and the World Climate Research Programme. Its study underscores the interconnectedness of polar regions with the global climate system and the need for sustained observation.

Category:Glaciers of Antarctica Category:Geography of East Antarctica