Restless Katla Volcano Heightens Fears Of Possible Eruption
By MARK DUNPHY
Sun Oct 16,2011
An increase overnight of seismic actvity in the vicinity of the Katla volcano in southern Iceland has heightened fears of a possible eruption.
Katla is located on the Mýrdalsjökull glacier, which is the southernmost glacier in Iceland and is almost 600 km2. It is situated to the north of Vík í Mýrdal and to the east of the smaller glacier Eyjafjallajökull, where an eruption in 2010 caused major disruptions to air traffic throughout western and northern Europe in April and May 2010. The caldera is 10 km (6 mi) diameter and is covered with 200–700 metres (660-2,300 ft) of ice.
Sixteen eruptions have been documented at Katla between 930 and 1918 at intervals of 40–80 years. It has not significantly erupted for 93 years, although there may have been small eruptions that did not break the ice cover in 1955 and 1999. The 1918 eruption resulted in extending the southern coast by 5 km due to laharic flood deposits.
In the early hours of today, 05 October, an intense swarm of earthquakes was registered in the Katla caldera; the largest of these earthquakes had a local magnitude of ~3.7. Most of the ongoing seismicity is sourced at shallow (< 5 km) depths.
Commenting before the latest (14-15 Oct., 2011) earthquake swarm, the IMO said there were no measurable signs that an eruption of Katla was imminent.
“However, given the heightened levels of seismicity”, the IMO added, “the situation might change abruptly. Monitoring teams at IMO are following the ongoing activity closely, and sensor-based networks around the volcano ensure that all seismological, geodetic, and hydrological changes are detected.”
“It is definitely showing signs of restlessness,” commented Pall Einarsson, a professor of geophysics at the University of Iceland.