West Antarctica and Dry Valleys

Abstract

Abstract West Antarctica has warmed by c.2°C (3.6°F) over the past 100 years. Ice shelves at the terminations of the large Pine Island and Thwaites Glaciers are melting from beneath. Antarctica has lost about 5 Gt of ice since 1980, mostly from that process. Much of West Antarctica is a widening and subsiding rift basin occupied by the sea, on which floats the Ross Ice Shelf. Mount Erebus is an active volcano in the rift valley. Incursions of warm ocean water beneath the ice shelf have melted it away in the past (e.g., Pliocene, 3.5 million years ago) and will do again if global warming reaches 2°C (3.6°F) (which would be twice that near the pole). Marie Byrd Land has high heat flow and under-ice volcanoes, possibly because it is located over a hot mantle plume. Local atmospheric conditions have encouraged the development of lakes and microscopic life in the Dry Valleys.