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Right call to issue eruption alert

By Svavar Hávarðsson
Vísir
„Right now we're analyzing what was going on. As of now we don't know, but we'll keep analyzing and add it to the data pool," says Sigrún Karlsdóttir, director of the Nature Watch at the Icelandic Meteorological Office, when asked what exactly gave such clear signs that a small eruption had started under the Dyngjujökull glacier on Saturday.



False signs

Low frequency waves that were detected by seismographs around noon on Saturday were interpreted by experts at the Icelandic Meteorological Office that a small amount of magma had erupted under Dyngjujökull. This activity went on for several hours but reduced in strength as time passed.



Readings from on board the Coast Guard's helicopter, as well as readings from the water level system showed no significant changes. As the day drew on, it became obvious that this had not been an eruption. Sigrún claims that the experts at the Icelandic Meteorological Office had not reacted too quickly, but it had been necessary to react to the signs detected. In the case of a real eruption, the series of events can be very quick to happen.



"It was the right decision at the time. In prior eruptions these signs have indicated that an eruption had started. We thought it right to react immediately," says Sigrún. No other evidence has surfaced to indicate than the activity signaled that an eruption had started.



Groundwater?

Magnús Tumi Guðmundsson, professor of geophysics, says that no one knows what caused this particular activity that was interpreted as the beginning of an eruption. Opinions differ on the topic.



"We've never monitored a situation like this with our current equipment. We'd have to go back to the Gjálp eruption in 1996 to find a comparable event, but we had different equipment back then and it didn't reach as far onto the highland. We're always learning from past experience. We don't know everything about how these instruments behave or what signals they send under various circumstances," states Magnús Tumi, adding that one plausible theory is that the magma under the Dyngjujökull glacier came into contact with groundwater, and the resulting reaction was picked up by the instruments. But as is this is only an unproven theory.



Magnús also eliminates the possibility of an equipment malfunction. "It was a real signal, just not an eruption."



270 million cubic meters

As of late last night (Sunday) there had been close to 2000 registered earthquakes, both by the Bárðarbunga caldera and at the north end of the subterranean cavern at the edge of the Dyngjujökull glacier. Most of the quakes originate from the north end of the cavern, but seismic activity is now registering north of the glacier, and it also seems that the magma has slowed down in speed. Two earthquakes greater than 5 on the Richter scale have been registered near the Bárðarbunga caldera, they are the largest earthquakes registered in the area since 1996.



The latest data from GPS readings indicate that magma is still flowing into the cavern under Dyngjujökull and that it is reaching further north. 3D models based on the date indicate that the total volume of magma in the cavern is now 270 million cubic meters.



Added probability

Haraldur Sigurðsson, volcanologist, ponders in a blog post late last night what would happen if the magma flow would reach Askja, but the magma flow has changed course and is now on a direct course towards the Askja caldera. The magma would only have to travel 25 kilometers to reach it, and there are plenty of examples of subterranean caverns that have traveled such distances. History shows us, according to Haraldur, that magma always reaches the surface where rock caverns break through the earth's crust at altitudes close to sea level. "That means that now is the greatest chance of an eruption, as the cavern makes its way through the crust underneath the sands north of the Dyngjujökull glacier and south of Askja," Haraldur writes.

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Composed music from the Bárðarbunga quakes

"All music is just data, in a way. You can interpret Beethoven's Fifth Symphony as data, which is just notes of variable pitches at variable times. In that way, earthquakes are no different."

Sub-glacial volcanic eruption under Dyngjujökull glacier

A small sub-glacial volcanic eruption has now started under the icecap of Dyngjujökull glacier in the Northern part of Vatnajökull glacier. There is no visible eruption cloud and the eruption could remain sub-glacial.

An eruption in Dyngjujökull glacier

Scientists at the Icelandic Met Office believe that a small sub-glacial volcanic eruption has now started under the icecap of Dyngjujökull glacier in the Northern part of Vatnajökull glacier

The largest earthquake yet

A magnitude 5.3 earthquake has occurred in the Bárðarbunga caldera at 5 km depth at 00:09. It is the strongest event measured since the onset of the seismic crisis at Bárðarbunga.

Activity in Bárðarbunga volcano

Over the last seven years seismic activity has been gradually increasing in Bardarbunga and the fissure swarm north of the volcano.

International air traffic not affected

International flights still operate to and from Keflavik International Airport, in spite of the eruption in Dyngjujökull glacier, near Bárðarbunga, which started earlier today.

Magma flowing into Bárðarbunga caldera with great force

All highland roads north of Vatnajökull glacier have been closed and all traffic banned, whether by vehicle or on foot. The Bárðarbunga situation is now attracting worldwide attention on a scale similar to the Eyjafjallajökull eruption in 2010.

2800 earthquakes in three days

Of these around 950 have occured since midnight today. Several of these events were larger than magnitude 3.

Icelandair stocks shake in quake scare

Icelandair stocks have dropped sharply since Monday morning. Market analysts agree that the situation at Bárðarbunga is a large factor.

No-Fly Zone

A large part of southeastern Iceland is a no-fly zone due to the eruption in Dyngjujökull glacier. The decision about the no-fly zone is re-estimated every two hours.

"There is full reason to expect an eruption"

The seismic activity in Bardarbunga on the Vatnajokull glacier is very powerful and therefore full reason to expect a volcanic eruption according to a specialist at The Icelandic Meteorological Office. A live webcam has been placed in the vicinity of Bardarbunga.




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