Antarctic volcanoes
"Another factor might be contributing to the thinning of some of the Antarctica's glaciers: volcanoes.
In an article published Sunday on the Web site of the journal Nature Geoscience, Hugh Corr and David Vaughan of the British Antarctic Survey report the identification of a layer of volcanic ash and glass shards frozen within an ice sheet in western Antarctica."
http://www.iht.com/articles/2008/01/20/europe/climate.php
Linked from Instapundit
This reminds me of how vast and unexplored Antarctic is.