Might indicate a sub-glacial eruption, but this needs confirmation.
A seismic swarm has been ongoing at Bárðarbunga volcano since yesterday with near continuous earthquakes. The depths of earthquakes are in the upper crust and their magnitudes are mainly around 1.5; a few earthquakes are of magnitude greater than ML3.
Bárðarbunga volcano is located under the northwestern part of the Vatnajökull ice cap.
The last eruption of Bárðarbunga volcano took place more than 200 years ago, in 1797, while neighboring Hamarinn volcano erupted in 1910.
Thanks to Wanda and Laurel for these links