Update on the eruption in Bardarbunga, Vatnajokull, Iceland

October 7th, 1996

Over the weekend the eruption has continued at a similar level as before. Seismic activity is slowly diminishing, with occasional surges in volcanic tremor. Weather has prevented closer observation, but an overflight this afternoon showed that the eruption cloud rises to an altitude of 13 000 feet.

The waterlevel in the Grimsvotn caldera was approximately 20 meters higher than has been observed previously, but there is still no sign of a glacier burst. Preparations have been made to install a continuous GPS monitor on top of the ice cover within the caldera in order to monitor any changes in the lake level which would signal the beginning of water flow out of the caldera lake. Weather conditions have, however, prevented helicopter access to the area.

Chemical analysis of a single ash sample collected on Oct. 3rd show that the ash is different in composition from previous products of this general area. The material is considerably evolved, appoaching basaltic andesite, and appears to have more in common with Bardarbunga products than products from Grimsvotn. This one sample may represent an initial product not necessarily representative of the bulk of material emitted from the volcano.