There are currently 25 active volcanoes (denoted by red triangles ),on the Antarctic plate, Mount Erebus has been continuously active since 1972
The sun, acting on the resultant aerosol gases, causes depletion of the ozone layer, in winter it recovers, [ misinterpretation (helped by Du Pont) of the term ‘aerosol gases’ lead to the “Ozone Hole” scare of the 1970s. see – http://www.capitolhilloutsider.com/unresolved-crisis-of-ozone-depletion/ ]
Click on Erebus in this list – http://www.volcanodiscovery.com/erupting_volcanoes.html
2013 Satellite views of Erebus http://earthobservatory.nasa.gov/IOTD/view.php?id=87444
Geothermal heating under Marie Byrd Land, plus the Larson B & Ross Ice Shelves has caused some limited melting – https://wattsupwiththat.com/2015/07/10/study-finds-surprisingly-high-geothermal-heating-beneath-west-antarctic-ice-sheet/ & http://archive.reportingclimatescience.com/ & https://news.wustl.edu/news/Pages/Antarctic-seismic-survey.aspx
Map of the West Antarctic Rift System https://www.ldeo.columbia.edu/~mstuding/tam_map_large.html
Rift basins exist in Ellsworth Land, linking GVIS and the Byrd Subglacial Basin, where elevated heat flow is likely to have influenced ice sheet development and stability. http://nora.nerc.ac.uk/10734/
All the sea ice graphs & links in one handy place for easy reference.