Iceland closed the airspace near the Bardarbunga volcano on Saturday, warning that significant emission of ash into the atmosphere is likely.
The Icelandic Meteorological Office raised the aviation alert at Bardarbunga to "red," which means that eruption is imminent or in progress.
http://www.cnn.com/2014/08/23/world/...html?hpt=hp_t2
Nothing has yet broken through the surface, and could ultimately remain sub-glacial...or not.