I have been thinking about the possibility of subglacial volcanism having a potential large impact on glacial ice mass, melting and climate in the past. Since there are volcanos all over the world, I thought there likely are plenty of subglacial volcanoes as well, but I find it hard to find much information on the topic, although I've read these recent publication, Evidence of an active volcanic heat source beneath the Pine Island Glacier https://www.nature.com/articles/s41467-018-04421-3, A new volcanic province: an inventory of subglacial volcanoes in West Antarctica http://sp.lyellcollection.org/content/461/1/231.abstract which present evidence of active volcanism under West Antarctica. One of the authors of the second paper, Robert Bingham said, “Theory suggests that this is occurring because, without ice sheets on top of them, there is a release of pressure on the regions’ volcanoes and they become more active.” Finally, my questions are: How much do we actually know about the volcanic history of Earths north and south poles? It seem that we have a lot of theories about how volcanism, asteroids, comets, and other factors have impacted global climate over geologic time scales, but how reliable are they? Is it possible that past super volcano or location of an asteroid impact is hiding under glacial ice for example? And, to what extent do we expect it to be possible for subglacial volcanism to affect current ice melt in the best to worse cases?