Aerial view down into summit crater of Korovin volcano on Atka Island. Roiling pool occupies bottom of crater; ash covers snow and ice inside crater.
McGimsey and others (2008) and Neal and others (2009) detail satellite imagery and field observations of ash on the upper east flank of Korovin volcano in late June - early July, 2004, likely from a small phreatic eruption of Korovin prior to late June.