Powerful Icelandic Volcano Grimsvotn Erupts; If the Katla Volcano Blows, We Could Have Serious Global Cooling, Triggering Widespread Food Shortages and Famine

The eruption of Iceland’s Mount Eyjafjallajokull volcano in March 2010 was a relatively minor event by volcanic standards. Much of its ash cloud stayed out of the stratosphere, where it would reflect sunlight, bringing cooler temperatures to the northern hemisphere. Unfortunately, there is a very real chance Eyjafjallajokull’s much larger neighbor, the Katla volcano, could blow its top, creating the third-climate driver in the Triple Crown of Cooling. If Katla does erupt, it would send global temperatures into a nosedive, with a big assist from the cool Pacific Decadal Oscillation (PDO) and a slumbering sun. Katla erupts about every 70 years or so, most recently in 1918, often in tandem with neighboring Eyjafjallajokull, which is not a good sign. Major volcanic eruptions throughout history bear witness to the deadly impact of volcanoes. And Katla, with its large magma chamber, would register high on the Volcanic Explosivity Index, if it were to erupt. When it unleashed its fury in the 1700s, the volcano sent temperatures into a tailspin in North America. Katla could cause some serious weather changes, depending on the duration of the eruption, and how high the ash gets blasted into the stratosphere. - Kirk Myers, Triple Crown of Global Cooling Could Pose Serious Threat to Humanity, Seminole County Environmental News Examiner, May 19, 2010

Scientists: Iceland's Grimsvotn Volcano Erupting

Iceland's Meteorological Office confirmed that an eruption had begun at the Grimsvotn volcano, accompanied by a series of small earthquakes. Smoke could be seen rising from the volcano, which lies under the uninhabited Vatnajokull glacier in southeast Iceland. A no-fly zone has been designated for 220 kilometres in all directions from the eruption. Isavia, the company that operates and develops all airport facilities and air navigation services in Iceland, described this as standard procedure around eruptions. - No-fly zone established after volcano in Iceland erupts, The Associated Press, May. 21, 2011

May 21, 2011

AP - Iceland's most active volcano has started erupting, scientists said Saturday — just over a year after another eruption on the North Atlantic island shut down European air traffic for days.

Iceland's Meteorological Office confirmed that an eruption had begun at the Grimsvotn volcano, accompanied by a series of small earthquakes. Smoke could be seen rising from the volcano, which lies under the uninhabited Vatnajokull glacier in southeast Iceland.

A no fly zone has been designated for 120 nautical miles (220 kilometers) in all directions from the eruption. Isavia, the company that operates and develops all airport facilities and air navigation services in Iceland, described this as standard procedure around eruptions.

"The plume of smoke has reached jet flying altitude and plans have been made for planes flying through Icelandic air control space to fly southwardly tonight," said Hjordis Gudmundsdottir, the spokeswoman for Isavia.

Grimsvotn last erupted in 2004. Scientists have been expecting a new eruption and have said previously that this volcano's eruption will likely be small and should not lead to the air travel chaos caused in April 2010 by ash from the Eyjafjallajokull volcano.

History shows that previous eruptions in Grimsvotn have not had much influence on flight traffic — unlike the massive disruption caused last year.

Pall Einarsson, geophysicist at the University of Iceland, said last year's eruption was a rare event.

"The ash in Eyjafjallajokull was persistent or unremitting and fine-grained," Einarsson said. "The ash in Grimsvotn is more coarse and not as likely to cause danger as it falls to the ground faster and doesn't stay as long in the air as in the Eyjafjallajokull eruption."

A plane from the Icelandic Coast Guard carrying experts from the University of Iceland will fly over the volcano and evaluate the situation.

One eyewitness, Bolli Valgardsson, said the plume rose quickly several thousand feet (meters) into the air.

Sparsely populated Iceland is one of the world's most volcanically active countries and eruptions are frequent.

Eruptions often cause local flooding from melting glacier ice, but rarely cause deaths.

Last year's Eyjafjallajokul eruption left some 10 million air travelers stranded worldwide after winds pushed the ash cloud toward some of the world's busiest airspace and led most northern European countries to ground all planes for five days.

Whether widespread disruption occurs again will depend on how long the eruption lasts, how high the ash plume rises and which way the wind blows.

In November, melted glacial ice began pouring from Grimsvotn, signaling a possible eruption. That was a false alarm but scientists have been monitoring the volcano closely ever since.

The volcano also erupted in 1998, 1996 and 1993. The eruptions have lasted between a day and several weeks.

Flashback: Could Icelandic Volcano Katla Erupt Soon?

May 10, 2010

BBC News - As scientists and air travelers 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. Kathryn Goodenough 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."

Overdue eruption

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 being produced.

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."

Flooding concern

Katla is much larger than Eyjafjallajokull, with a magma chamber about 10 times the size.

If and when it does go off, the combination of the magma and the large ice sheet covering the volcano could lead to explosive activity for a long time, says Dr Goodenough.

It is the explosive nature of the current volcanic eruption, which caused an ash plume to be sent high into the atmosphere and affect flights in the UK and Europe.

More worryingly for the people of Iceland, an eruption at Katla would probably cause major flooding. The volcano's ice sheet is 600-700m thick and all of this ice would quickly melt on to the surrounding area, which is primarily agricultural land.

But Professor Gudmundsson says there are "no signs yet" of an impending eruption.

"Our eyes are not glued to Katla, we are thinking about the eruption that is happening now."

Flashback: Katla Volcano in Iceland Shows Signs of Increased Activity

May 26, 2010

The Clare Herald - Fears are growing that the Katla volcano in Iceland could soon erupt after volcanic activity at the site increased by over 200% in recent days.

Seismic readings of the volcano indicate the tremors around the area have increased substantially.

Four earthquakes were detected near Katla during a 12-hour period on May 21st, more than at any other time since the Eyjafjallajokull volcanic eruptions first occurred in March.

Three earthquakes at the Katla Volcano were reported by the Disaster and Emergency website Hisz.rsoe.hu on Sunday evening. The tremors may have been due to ice movements within Mýrdalsjökull glacier or magma movement under the volcano.

The last earthquake to take place at the volcano was recorded this morning.

The eruption of the long-dormant Eyjafjallajökull volcano has prompted fears among some geophysicists that it might trigger an eruption at the larger and more dangerous Katla. In the past 1,000 years, all three known eruptions of Eyjafjallajökull have triggered subsequent Katla eruptions. The last large eruption at Katla was in 1918 but there have been small eruptions at Katla as recently as 1955.

An eruption of Katla volcano has the potential to be more devastating than the current eruption of Eyjafjallajokull. Geophysicists at Iceland’s Institute of Earth Sciences say Katla would be locally and globally damaging.

Icelandic President Ólafur Grímsson has warned Governments around Europe that a significant eruption at the volcano is ‘coming close’. He said:

“We [Iceland] have prepared … it is high time for European governments and airline authorities all over Europe and the world to start planning for the eventual Katla eruption”.