Antarctic Snow Reveals Volcanic Links to Climate

Remnants of volcanic smoke locked up in Antarctic ice could help geologists establish firmer links between ancient eruptions and climate changes.

Sulphur isotopes in the ice could show whether eruptions of dust and ash up to a million years ago were large enough to reach the upper atmosphere, and so block sunlight.

Mélanie Baroni, at the Université Joseph Fourier in St Martin d'Hères, France, and colleagues drilled ice cores to provide a record of historical eruptions. Particles from major eruptions spread across the globe, and are deposited as thin layers on the Antarctic snow, Baroni explains.

The Antarctic region is a particularly good place to study these layers because they tend to be well-preserved and are uncontaminated by human-made sulphur emissions, says Baroni.