Here some info about Katla?
Katla Volcano Update 21 May 2010
The earthquakes at the Katla volcano site appear to possibly be increasing in frequency as of this moment (time will tell however). Since May 17 there
have been four earthquakes at or very near Katla, while a 5th just on the edge of the Myrdalsjokull glacier.
Although 4 or 5 earthquakes at the volcano site in 4 days does not indicate a drastic change in pattern, the interesting notation at the moment is the
fact that the two most recent earthquakes occurred within 3 hours of each other on 21 May, 2010, at depths of 5km and 13km. That in itself is an
increase in occurrence. It may be an anomaly, but it justifies keeping one eye on Katla, the big sister of Eyjafjallajokull.
What do these volcanic earthquakes tell us about what is going on at the Katla volcano?
One type of volcanic earthquake may indicate that changes are occurring due to magma moving in to an area of the rock which changes the pressure
around it. At some point, the rock will break or move. If this type of earthquake becomes frequent, and a lot of earthquakes begin occurring or
swarming (Earthquake swarms are when we suddenly start seeing clusters of earthquakes in the same general area over a relatively short period of
time), it may be a precursor warning that an eruption is about to happen.
What we are seeing at Katla, in my opinion is NOT cause for immediate alarm, but it is noteworthy to observe this recent activity and to stay up to
date with what is happening there.
There is something going on beneath the ice.
Uh-oh! Katla Volcano Just Rumbled
Katla historically erupts following the eruption of Eyjafjallajokull (April 14), is possibly 10 times more powerful, and has the potential to cause
Earthquake Map Source: Icelandic Meteorological office – their maps show only last 48 hours, so I have kept a separate view to include the Katla
quakes since 17-May-2010 as of this post date
Posted: May 21, 2010 | By: Modern Survival Blog
The bbc talking about Katla?
Could another Icelandic volcano erupt soon?
ICELAND'S major volcanoes and tectonic plate boundaries.
As scientists and air travellers alike keep a close eye on Iceland's ongoing volcanic eruption, some reports suggest that another, much bigger,
volcano could stir in the near future.
Katla is Eyjafjallajokull's more active neighbour, and scientists believe that there may be a link between the two volcanoes.
This link has not been physically proven, explains Magnus Tumi Gudmundsson a geophysicist from the University of Iceland. A circumstantial, historical
connection "is putting people's eyes on Katla," he says.
"We know of four Eyjafjallajokull eruptions in the past [dating back to AD 500] and in three out of these four cases, there has been a Katla eruption
either at the same time or shortly after.
"By shortly, I mean timescales of months to a year.
"We consider that the probability of Katla erupting in the near future has increased since Eyjafjallajokull went."
Kathryn Goodenough from the British Geological Survey points out that, as yet, there is no physical explanation for this apparent link.
It seems that when Eyjafjallajokull goes off, Katla tends to follow.
British Geological Survey
"Scientists don't yet know what the connection is," she says.
"But we know there are fissures running between the two volcanoes. And they're quite close to each other.
"They're also being subjected to the same tectonic forces. So the chances are that if magma can find a pathway to rise beneath one of them, it can
find its way to rise beneath the other."
Researchers do know that the two volcanoes have separate magma chambers, but many suspect that these chambers are physically linked in some way, deep
beneath the surface of the Earth.
"But this is only speculative," says Dr Goodenough. "We don't have geophysical evidence that makes that clear."
Katla's last eruption was in 1918. It lasted for three weeks and up to a cubic kilometre of material exploded through its vent.
"It's a much more active volcano than Eyjafjallajokull - it has had about 20 eruptions in the last 1,000 years, so it erupts about once every 50
years on average," says Professor Gudmundsson.
The combination of ice and magma makes for an explosive eruption
"At first glance people would say it's now long overdue. But the larger the eruption, the longer the pause (in) time that follows it, and that 1918
eruption was large."
At the moment, there is no seismic activity detectable underneath Katla that would indicate that magma is moving upward underneath it.
Scientists from the Icelandic Meteorological Office are looking at such signals and updating their website regularly with the seismic data that is
But Dr Goodenough points out that, with Eyjafjallajokull "we only had a few hours warning".
"Seismic monitoring does not necessarily give you advance notice of an eruption."
But it remains a case of watch, wait and look for signs of activity, because it is almost impossible to draw clear conclusions from the historical
record, which is simply too short.
While both volcanoes have been repeatedly erupting for hundreds of thousands of years, the earliest eruptions on scientists' records occurred about
8,400 years ago.
Dr Dave McGarvie, a volcanologist from the UK's Open University, who has carried out extensive research in Iceland, explains that in that time Katla
has erupted as many as 300 times.
"If we simply look at the historical record, then yes, there appears to be a link [between the two volcanoes]," he says. "But Katla does go off
independently, so the link it could be pure co-incidence.
"We just don't have a pattern to get a grip of."
Professor Gudmundsson adds: "We haven't established any physical link [between the volcanoes] - we only have this circumstantial evidence," says .
"And we simply don't have enough data to be able to work out what the probability of a Katla eruption is."