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.
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.
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.
"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."
100000 flights were cancelled during the Eyjafjallajökull eruption. It is doubtful that the same will happen again.
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.
At about 3 a.m. this morning (16 August), an earthquake swarm began by Bárðarbunga volcano in NW Vatnajökull ice cap.
Ongoing magma movement in Bárðarbunga for the past days have raised questions of possible flight disruptions between Iceland and Europe.
Seismologists at the Icelandic Meteorological Office (IMO) have reclassified the earthquake close to the Bardarbunga volcano last night.
A 24-year old employee of CCP Games has set up a website that shows the seismic activity at Bárðarbunga in a 3D perspective.
The Icelandic Met Office has lowered the aviation alert level for flights.
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
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.
Over the last seven years seismic activity has been gradually increasing in Bardarbunga and the fissure swarm north of the volcano.
Scientists differ on how to interpret several large quakes from Thursday that originated in the center of the Bárðarbunga caldera.
International flights still operate to and from Keflavik International Airport, in spite of the eruption in Dyngjujökull glacier, near Bárðarbunga, which started earlier today.
270 million cubic meters of magma has gathered underneath Dyngjujökull in just one week.
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.
An earthquake of magnitude 4.7 shook the Bardarbunga volcano just before midnight last night.
Of these around 950 have occured since midnight today. Several of these events were larger than magnitude 3.
Icelandair stocks have dropped sharply since Monday morning. Market analysts agree that the situation at Bárðarbunga is a large factor.
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.
The current situation at Bárðarbunga is many times more powerful than the one that led to the Gjálpar eruption in 1996.
Close to 300 earthquakes were recorded there last night, of which two reached over 3 on the Richter scale.
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.
During three hours of aerial surveillance, there were no obvious signs of volcanic activity.