Antarctic ice sheet

Ice shelf

Ice sheet

Antarctic sea ice

Geology

Structural basin

Iceberg

Continental shelf

Cryosphere

Meltwater

Oceanography

Sea ice

Paleontology

Ice stream

Glacial period

Glacier

Nature

Geophysical and geological data reveal increased ice-sheet variability and surface meltwater—possibly analogous to future conditions—offshore of the Aurora subglacial basin of East Antarctica during warm climate intervals of the past 50 million years. The East Antarctic Ice Sheet contains the water equivalent of approximately 50 metres of sea-level rise. Understanding the past behaviour of this mass of ice is therefore of much interest in times of a rapidly warming climate. Sean Gulick, Amelia Shevenell and colleagues show that the Aurora subglacial basin of East Antarctica had marine-terminating glaciers by the early to middle Eocene epoch. Over millions of years, the amount of ice in the area repeatedly waxed and waned, but then stabilized by the cooler late Miocene and even through the warmth of the Pliocene. The study's geochemical and radar data suggest that the combination of warmer temperatures and increased surface meltwater—conditions that will possibly occur again in the future—influenced past ice s...

Initiation and long-term instability of the East Antarctic Ice Sheet