Seismic activity around Iceland’s Bardarbunga volcano has raised the possibility of an eruption that could have catastrophic consequences within Iceland and create atmospheric effects similar to those caused by the eruption of Iceland’s Eyjafjallajökull volcano in 2010. That event cost the airline industry alone about $1.7 billion. Earlier this week Iceland’s authorities raised the risk level for an eruption, evacuated settlements in the region of the volcano and restricted air and ground travel.
Gordon Woo, Catastrophist, RMS.
Bardarbunga has erupted at least 17 times in the last 800 years – the last eruption occurring in 1910 – and with a roughly twice-a-century frequency is due for another eruption, according to Gordon Woo, catastrophe expert at RMS.
“Before any eruption, there are likely to be precursory signals, such as an increase in seismic activity and deformation measured via GPS,” Woo comments. “Signals of this kind have been observed since Aug. 16, when a seismic swarm began.”
Hundreds of small earthquakes have been measured every day since, indicating movement of magma within the Bardarbuna volcanic system. Though these observations are ominous and fully warrant the regional evacuation measures, according to Woo, there is no evidence of a magma migration toward the surface, which would precede an eruption.
Image of seismic activity across Iceland in the early afternoon of Aug. 22, local time. Red indicates events within the last four hours.
That is not to say there won’t be. Also, the possibility exists for what Woo characterizes as an explosive subglacial eruption, which would lead to glacier melt, causing an outburst flood. “An outburst flood could have catastrophic consequences in the region around the volcano, especially if there were damage to the hydroelectric power infrastructure,” Woo observes.
If there were to be a surface eruption, significant amounts of ash could drift over Northwest European airspace, given the right wind condition, Woo cautions. However, he adds, “This eruption should be far less disruptive to flights than Eyjafjallajökull in 2010, since the laws on flying through a very low density ash cloud are no longer based on a rigid application of the precautionary principle.”
Projection of Bardarbunga’s potential ash trail by Norway’s Meteorological Institute.
As seismic activity moderated over last night, Woo estimated that the probability of a significant eruption was about 10 percent.
This morning in Iceland, a local publication noted that the country’s scientists couldn’t agree on how the latest seismological readings should be interpreted.
Kristín Vogfjörð, Director of Research at the Icelandic Met Office believes that based on her interpretations of the GPS data, the pressure is receding and the likelihood of eruption is minimising.
Meanwhile, Ingi Þorleifur Bjarnason, a research scholar with the Insitute of Earth Sciences at the University of Iceland interprets the data differently, believing that the pressure is increasing and that the volcano is rising in preparation for eruption.
Magnús Tumi Guðmundsson, geophysicist and professor at the University of Iceland has said that really, it could go either way.
At 1:00 p.m. local time, Iceland’s Meteorological Office reported that there were no signs that seismicity was decreasing. The latest report at press time noted that a 25 km-long dyke had formed under a glacier associated with the Bardarbunga volcano, and that the latest data suggested that magma continued to move along the dyke, possibly branching further its northeast end. The report also noted that the aviation color code remained at “orange” – the second highest of five stages before “red” – signifying continued high levels of activity within the system.
The latest seismological activity across Iceland (as depicted in a snapshot image above) from the country’s Meteorological Office can be seen by clicking here.