Antarctic Glaciers

Antarctic glaciers are beautiful and awe-inspiring. They affect us through their connections with the ocean and sea level, and environmental change is having rapid consequences in Antarctica. Antarctica is the world’s largest ice sheet, covering ~14,000,000 km2. Much of the ice sheet surface lies above 3000 m above sea level. This massive thickness of ice drowns whole mountain ranges, and numerous volcanoes exist underneath the icey exterior. It’s the world’s fifth largest continent, and it is, on average, the highest and coldest continent. Antarctica provides a unique record of the Earth’s past climate, through the geomorphological record of glacier moraines, through ice cores, through deep sea sediment cores, and through past records of sea level rise.

The Antarctic continent comprises three ice sheets: the Antarctic Peninsula Ice Sheet, the West Antarctic Ice Sheet, and the East Antarctic Ice Sheet. Most of Antarctica is covered by ice (~98%), with ice-free areas on, for example, nunataks (high mountains poking through the ice sheet), James Ross Island and Alexander Island on the Antarctic Peninsula, and the McMurdo Dry Valleys in East Antarctica. The Antarctic Ice Sheet is drained by fast-flowing ice streams, which respond quickly to climate change; they can thin, accelerate, recede, or even stop flowing entirely. Beneath the thick skin of ice, there is flowing water and subglacial lakes. Despite the aridity and cold temperatures, there is life on the ice, in the ice and underneath the ice.

Antarctic glaciers terminate on land or in the sea, as floating ice shelves or grounded or floating outlet glaciers. The Antarctic Ice Sheet contains 25,400,000 km3 of ice, which, if it melted, would be equivalent to a sea level rise of 58 m[1]. The ice sheet is over 4000 m thick in places, and in places, the West Antarctic Ice Sheet is grounded more than 1500 m below sea level[2]. The coldest temperature ever recorded on Earth was at Vostok: -89.2°C on 21st July 1983. The Dry Valleys of Antarctica are the most similar place on Earth to the desolate landscapes of the Moon and Mars.

This website aims to introduce some key concepts in Antarctic glaciology. These are explored in our Science Themes, and include descriptions of different types of glacier, ice shelves, and ice streams. This website also explores the recent rapid environmental changes happening today in Antarctica, and how changes in atmospheric and ocean temperatures has led to ice-shelf collapse, rapid glacier recession and sea level rise.

Click through each of the Science Themes on the website to discover more about Antarctic glaciers. Italicised words are defined in the Glossary. Alternatively, ask a me a question through twitter (@Antarcticglacie) or Ask a Scientist!

This website was written by Dr Bethan Davies from the University of Reading as part of an ongoing commitment to education, outreach and impact.

 

1. Lythe, M.B., Vaughan, D.G., and the BEDMAP Consortium. 2001. BEDMAP: a new ice thickness and subglacial topographical model of Antarctica. Journal of Geophysical Research, 2001. 106(B6): p. 11335-11351.

2. Joughin, I. and Alley, R.B., 2011. Stability of the West Antarctic ice sheet in a warming world. Nature Geosci, 2011. 4(8): p. 506-513.

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