Volcanic Eruption Under Ice
by Liz Olson
Although Antarctica is now a fairly quiet place volcanically, sometime around 325 B.C., an active volcano hidden deep beneath the ice in the Hudson Mountains, West Antarctica, erupted, puncturing several hundred yards of ice above it. The ash and debris from the volcano rocketed into the air and then settled on top of the ice, creating a layer that is now out of sight after 23 centuries of snowfall.
Hugh F. J. Corr and David G. Vaughan, of the British Antarctic survey, published a report in January 2008 on the Nature Geoscience website about the recently discovered volcano.
American and British scientists were able to see the buried layer of volcanic ash with radar surveys performed in 2004 and 2005. In earlier radar surveys of the area, the layer of ash was so thick it was mistaken for bedrock. With more advanced radar, scientists were able to distinguish between the layer of volcanic ash and the bedrock located further below. Although the exact location of the eruption is unknown, the estimated year of the eruption, 325 B.C., is based on the thickness of the ice above and spikes in the concentration of acids in the ice. This eruption, which occurred during the time of Alexander the Great, was probably similar to the explosive under-ice volcanic eruption in Iceland in 2004, which sent ash seven miles in the air.
Glaciologists have suggested that heat from a volcano below the ice could be speeding up the thinning of the nearby Pine Island Glacier. It would unlikely affect other glaciers, however. Most glaciologists still attribute glacier melting to warmer ocean water caused by global warming.