From post 295 here: http://scienceblogs.com/eruptions/2010/05/eyjafjallajokull_update_for_53.php#comments Iceland Met office update: Assessment 04 May 2010 19:00 Plume was observed at 5.8-6 km height (19-20,000 ft) estimated from the Icelandic Coast Guard (ICG) flight at 10:40 and 15:30 GMT. It is heading east-south-east to south-east from the eruption site. Plume track clearly visible up to 300-400 km distance from the eruption site on a NOAA satellite image at 13:13 GMT. Water levels have been rather constant. Water temperature at Markarfljot bridge was low this morning (below 2°C) but seems to be rising (about 5°C at noon). Water level seems to be slightly decreasing. Lava is still flowing northwards, forming a lava fall down the steep hill under Gígjökull, about 4 km north of the crater. Blue gas is seen rising from the lava and white steam plumes are seen somewhat lower and mark the front of the lava stream. The size of the eruptive crater is 280 x 190 m. Lava splashes are thrown at least a few hundred meters into the air. Overall assessment is that it is more explosive activity and ash production than was observed yesterday. Progression of the lava seems to be slower than yesterday. Presently there are no indications that the eruption is about to end. No measurable geophysical changes within the Katla volcano.