Scientists have mapped 138 volcanos below the ice in the Western Antarctic Rift. Most are hidden below one-mile sheets of ice.
Volcanic activity is unknown, but eruptions could increase melting ice, contributing to natural rise in ocean levels.
And they were not put there by man …
Source: “A New Volcanic Province: An Inventory of Subglacial Volcanoes in West Antarctica,” May 29, 2017, The Geological Society of London: http://sp.lyellcollection.org/content/specpubgsl/early/2017/05/26/SP461.7.full.pdf