Explosive activity increases slightly at Icelandic volcano

Explosive activity has increased, but not significantly, at Eyjafjallajökull volcano, according to a report posted Thursday night by the Icelandic Meteorological Office and the Institute of Earth Sciences of University of Iceland.

The eruption column is higher and the volcano is throwing out more tephra, meaning ash, rocks and larger chunks of material. "There are no signs that the eruption is about to end," the report, posted at 6:00 p.m. Iceland time, says.

Commercial pilots estimated the volcano's ash plume to be at 30,000 feet between 5:30 a.m. and 8:00 a.m. Thursday morning. When an Iceland Coast Guard helicopter went up at 1:00 pm. it was under 20,000 feet. An Icelandair Cargo flight which left Iceland at 6:00 p.m. climbing towards east from Keflavík estimated the height at 21,000 to 22,000 feet.

There was considerable ashfall at Þykkvabæjarklaustur in Álftaver, about 40 miles from the volcano. "Everything has turned black," the report says. It wasn't clear whether the ash cloud south of Eyjafjallajökull is ashfall or ash that has already fallen and is being blown from the ground.

Noises from the volcano were heard at Heggstaðanes, 125 miles to the north.

The amount of melt water coming off the Gígjökull glacier has been decreasing and is now running from the glacier's eastern side. The scientists speculate that the lava flow may be changing the direction of the melt water flow. That could be a problem because of the possibility of local flooding, they note.

The volcano's cinder cone continues to build up in the northern most ice cauldron.

The levelof seismic activity is decreasing, and is now similar to the beginnings of the volcano's eruptive phase between April 14 and 17. But even so, there were 10 earthquakes recorded from midnight Thursday onward. Most are below a magnitude 2, with the strongest being 2.2.

Measurements using global positioning satellites continue to show horizontal displacement around Eyjafjallajökull, with the stations drifting outwards.

By Elizabeth Weise