Kristin Jonsdottir, geophysicist at the Icelandic Met Office says that this morning, increased seismic activity and increased tremor was observed around the Bardarbunga caldera, especially in a 25 km. long dyke intrusion north and east of the caldera, near the edge of the Dyngjujokull outlet glacier.
Shortly after 2 PM GMT, the Met Office declared an aviation alert for a large area around Bardarbunga and said a small eruption was believed to have started under the glacier. No signs of glacial flood has been observed and scientists in a surveillance airplane above the glacier see no sign on the surface of the glacier. Even so, the measurements indicated a small eruption under the glacier and it is now believed that it was small enough, not to cause significant melting of glacial ice. A larger eruption can not be ruled out, according to the Met Office.
The dyke intrusion has been forming over the last few days. It is now believed to be around 25 km. long, and about 0,2 - 0,3 cubic kilometers of magma is thought to have entered the intrusion from a magma chamber beneath the Bardarbunga caldera.
At this stage measurements taken are based on a small event. The Jökulsárgljúfur canyon has been closed and evacuation of tourists in that area and around Dettifoss waterfall has started. The situation at this stage does not call for evacuation of habitants in Kelduhverfi, Öxarfjördur and Núpasveit. People in those areas are encouraged to watch news closely and have their mobiles switched on at all times.