Eruption About to Expire
“It seems to me there are many indications the eruptions is in its final stage,” Þorvaldur Þórðarson, volcanologist at the University of Iceland, tells Morgunblaðið , speaking of the Fagradalsfjall eruption in Southwest Iceland. “Some minor emission of gasses from the crater and from the lava has been detected, telling us there is still some life in there, although very little.”
The volcanic eruption, which began March 19, will not be declared over until the crater has been inactive for at least three months. To wait that long is the general rule followed. Five weeks have gone by since lava flow was last detected by Fagradalsfjall, so the crater will have to remain inactive for nearly another two months before the end of the eruption is declared.
When Eyjafjallajökull volcano erupted in 2010, the last activity was detected June 6 and 7, whereas the end of the eruption was not declared until October that year.
“When the eruption [by Fagradalsfjall] was the most forceful, the lava flow measured 5-10 m3/sec,” Þorvaldur explains. “For a volcanic conduit to stay open, the flow of hot lava has to be 3 m3/sec, and the production by Fagradalsfjall is now way below that. The emission of volcanic materials is very small.”
Seismic activity by Keilir mountain early in October suggests there is still magma underground on the Reykjanes peninsula, although minimal, he notes.
“A valid comparison might be to compare the eruption to a patient who still has some vital signs, but is on a respirator,” Þorvaldur states.
“Most of the residents would be happy to hear if this were over,” states Fannar Jónasson, mayor of Grindavík, the town closest to the eruption. Businesses in the travel industry have benefitted from it, while the pollution and the risk of lava flow have been a nuisance.