http://www.abc.net.au/news/stories/2011/07/06/3262975.htm
Experts say one of Iceland's most feared volcanoes looks ready to erupt, with measurements indicating magma movement, raising fears of a new ash cloud halting flights over Europe.
The Hekla volcano is close to the ash-spewing Eyjafjoell, which last year caused the world's biggest airspace shut down since World War II, affecting more than 100,000 flights and 8 million passengers.
The Iceland Civil Protection Authority says it is closely monitoring the situation.
"The movements around Hekla have been unusual in the last two to three days," University of Iceland geophysicist Pall Einarsson said.
While this might not necessarily mean an immediate blast, he says "the volcano is ready to erupt".
"The mountain has been slowly expanding in the last few years because of magma buildup," he said.
Another geophysicist, Ari Trausit Gudmundsson, also says the measurements around Hekla are very "unusual" and that the volcano looks ready to blow.
The volcano, dubbed by Icelanders in the Middle Ages as the "Gateway to Hell," is one of Iceland's most active, having erupted some 20 times over the past millennium, most recently on February 26, 2000.
Over the past 50 years, Hekla has gone off about once a decade.
It measures 1,491 metres and is located about 110 kilometres east of Reykjavik, not far from Eyjafjoell.
The news of a possible imminent eruption comes just over a month after this year's violent eruption at the Grimsvoetn volcano, in the south-east of the country.
That eruption subsided after less than a week, having spit out far more ash than Eyjafjoell, but due to more favourable winds for Europe caused far less air traffic disruption.
Mr Gudmundsson says the volcano tends to "produce both ash and lava within the first seconds of an eruption".
He says lava eruptions are far less disruptive to air travel.
"If the next eruption is of the same character [as the previous ones] it is unlikely that it will have any effects on flights in Europe," he said.
"But of course this depends on the size of the eruption, which is something that is impossible to predict."
Both of Iceland's latest eruptions provided warning signs several hours before, but Hekla is known for having a very short fuse.
"Hekla never gives you much of a warning," Mr Einarsson said.
He says in 2000, it began rumbling an hour-and-a-half before the outbreak of magma, which "was actually an unusually long warning".
"In 1970 we only got 25 minutes notice," he said.
Rongvaldur Olafsson, a project manager at the Icelandic Civil Protection Authority, says no immediate safety precautions are being taken.
"We will watch the mountain and developments very closely," he said.
After Iceland's last two eruptions, geologists have warned that the country's volcanoes appeared to have entered a more active phase and that more eruptions could be expected, with Hekla believed to be first in line.
Eruptuions have occurred in 874, 1158, 1206, 1222, 1300, 1341, 1389, 1510, 1597, 1636, 1693, 1766, 1845, 1947, 1970, 1980, 1991 and 2000.
Some of these eruptions caused great damage, especially the eruptions in 1510, 1693 and 1766.
