The following was received by the Smithsonian's Global Volcanism Network. This report is preliminary and subject to change as the event is studied in more detail. We will forward additional significant information as it becomes available.
Bergur Bergsson, eye witness was 13 km S of Kverkfjoll in the early morning reports: Steam 05:18 steam turned from light to dark. This is believed to indicate time of the eruption to break through the glacier. The fissure is believed to be appr. 10 km at north of Grimsvotn caldera The erupton column is at 12h 2 km over eruption site glacier rising to 6 km further north.
In the eruption 1938 not much tephra came from the eruption, but a lot of water came from Grimsvotn, making the jokulhlaup in Skeidara the largest one in the century
It is evident from eye witness and seismic information that the northern eruption site is near the watershed in Vatnajokull so some of the meltwater could travel north, to Jokulsa a Fjollum river, through Dettifoss waterfall to Axarfjordur Bay.
Wind blows ash from E Asarfjord to Skagafjordur. Later ash is predicted to be blown to N and then to S. Next 24 hours ash can be distributed all around the country if the eruption continues.
At Bardardalur N Iceland, very small tephra was falling at 12:00 and no marked increase at 15:00.
Warning been issued to farmers that fluor can be hazardous to sheep and cattle, in areas where ash is falling.
At 15:00 hrs. the activity seems to have increased in the last hours. This is evident as at At Bardarbunga more earthquakes activity has been for the last hours. It is possible that some eruption might start there, but this is to early to forcast. Bardarbuna is the a high area in W Vatnajokull reching 2000 m altitude. In early afternoon there is a cloud cover over the eruption site so direct observation is not possible, interpretation is mainly from seismic sources. Ashfall is very small or none yet in inhabited areas.
Helgi Torfason heto@os.is