Geolo­gists Ex­plore the His­tory of Cave Ice

Christoph Spötl and Gabriella Koltai from the University of Innsbruck investigate the Eisriesenwelt in Werfen in the province of Salzburg, one of the biggest ice caves worldwide. The researchers sample frozen water that is up to about 5000 years old. And they find evidence that the extent of underground glaciers in this 40 kilometre-long cave was much larger in the past.