A powerful volcano, Bardarbunga, (Bárðarbunga) might erupt in the Highlands of Iceland
A powerful volcano, Bárðarbunga, might erupt in the Highlands of Iceland.
The Icelandic Met Office has upgraded its aviation alert status to orange, meaning that a “volcano shows heightened or escalating unrest with increased potential of eruption.” Seismic activity is often the precursor of an eruption.
The orange alert is the second highest alert status. The next alert level, red, means that an eruption is either imminent or in progress. Bardarbunga last erupted in 1996.
Intense seismic activity
According to the website of the Icelandic Met Office: “the intense seismic activity that started on 16th of August at Bardarbunga persists. Very strong indications of ongoing magma movement, in connection with dyke intrusion, is corroborated by GPS measurements. There are currently two swarms: one to the E of Bárðarbunga caldera and one at the edge of Dyngjujökull just E of Kistufell. At 2.37 am on the 18th a strong earthquake (M4) was located in the Kistufell swarm.
This is the strongest earthquake measured in the region since 1996. As evidence of magma movement shallower than 10 km implies increased potential of a volcanic eruption, the Bárðarbunga aviation color code has been changed to orange. Presently there are no signs of eruption, but it cannot be [ruled out] that the current activity will result in an explosive subglacial eruption, leading to an outburst flood (jökulhlaup) and ash emission. The situation is monitored closely.”
Roads closed north of the Bardartunga volcano
Certain roads in the highland north of Vatnajökull glacier, where Bardarbunga is situated, have been closed due to risk to tourists in the area, including the road to Herðubreiðarlindir to Askja (F88) and Gæsavatnaleið route from Sprengisandur to Askja (F910). Travellers are advised to gather information on road-safety in the area close to Bárðarbunga. This information can be found here.
View video below with update what can happen.
Update: 19.08.2014 at 08:30 am GMT
About 950 earthquakes have been detected with the earthquake monitoring network of the Icelandic Meteorological Office (IMO), since midnight. Several of these events were larger than magnitude 3. The swarm initially started in the Bárðarbunga caldera and has been migrating in two clusters towards the north and the east of the volcano.
Yesterday, these two clusters were active east and north of Bárðarbunga as activity was migrating northeastwards. . While strongest events were located in the northern cluster, the highest number of events were detected in the eastern cluster.
The strongest event since the onset of the swarm was detected on Monday morning 02:37 in the northern cluster. Analysis revealed that its magnitude was 4.5 and it was felt in Akureyri and Lón in the northern part of the country. Since this morning, activity has significantly decreased in the northern cluster.
The eastern cluster is still active and two strong pulses occured between 10:45 and 12:00 as well as 16:50 and 17:30 today. Within the first pulse around noon, the cluster was again migrating northeastwards, but most events are now located between Bárðarbunga and Kverkfjöll. As reported earlier, GPS ground deformation data has evidenced that the earthquake swarm is caused by magma intrusion.
Throughout the whole sequence until now, the majority of events today was at 5-10km depth. No signs of migration towards the surface or any other signs of imminent or ongoing volcanic activity have been detected so far. IMO is monitoring the area around the clock very closely and will update in case of any changes.
Civil Protection is still on Uncertainty Phase, which means that course of events has started that may lead to natural hazard in the near future. The National Commissioner of Icelandic Police (NCIP) has today met with the Prime Minister of Iceland, Minister of Interior and government officials to consult on the issue. The NCIP also met with officials from the Ministry of Foreign Affairs, foreign embassies in Iceland and from key stakeholders in Iceland.
Mountain roads North of Vatnajökull, F88 (completely) and F910 (partly), have been closed for all traffic. That includes cars, bikes and hiking.
Update: 19.08.2014 at 19:25 pm GMT
The highland areas North of Dyngjujökull, where there has been a lot of seismic activity in recent days, is now being evacuated. The district commissioners of police in Húsavík and Seyðisfjörður in cooperation with Civic Protection announced this in a public statement this afternoon.
In addition, a Civic Protection danger phase has been declared in the area due to the unrest in Bárðarbunga.
Update: 20.08.2014 at 14:00 pm GMT
The situation in the northern part of Vatnajökull is unchanged. There is still very much seismic activity in the area which continues to move to the north east. The alert phase declared yesterday is still in place and the area has been evacuated.
The Icelandic Coast Guard will fly over the area today to see if any tourist are still there. The decision to evacuate the area is a precautionary action in case the seismic activity is a prelude for a volcanic eruption. According to information from the Icelandic Met office an earthquake has occurred almost every single minute today.
There has been a constant seismic activity in the area around Bárðarbunga in Vatnajökull since Saturday and nothing indicates that it is about to stop. The strongest earthquake of 4.0 took place on Monday. Whether this all will lead to an actual eruption remains a question.
This image shows earthquakes during the last 48 hours of the whole country
Update 20.08.2014 at 22:30 pm GMT
Icelandic Coastguard’s airplane landed at Reykjavik airport tonight. On board the plane were geologists returning from their flight over Bárðarbunga, amongst them Magnús Tumi Guðmundsson, one of Iceland’s leading geophysicists.
“The flight went well, we managed to gather the information we wanted. We did radar measurements of the glacier and the river Jökulsá á Fjöllum, which will be of much value in the event of an eruption,” he said in a telephone interview with mbl.is.
Magnús says it’s hard to evaluate the chances of an eruption. “It can go either way, nobody can really predict what will happen in this situation.”
A lot of ice to melt
He says that in the event of an eruption, one of two things would likely happen. “What’s more likely is an eruption below the glacier Dyngjujökull, where we can see earthquake activity moving northeast. In that area the glacier’s thickness measures half a kilometer, so it would have to melt a lot of ice before it could finally breach the surface.
Seismic activity in Bárðarbunga. Notice how the activity seems to be moving Northeast.
When that would happen, the eruption would change into an explosive one, similar to what happens when the Grímsvötn volcano erupts.”
“The other option is that the eruption would happen in the Bárðarbunga caldera, where the glacier is up to 800 metres thick, so it would have to melt its way through even more ice.”
Not a disasterous jökulhlaup (melted ice in rivers)
Magnús says that a jökulhlaup could follow and the river’s flow could reach up to ten thousand cubic metres every second. “If the eruption would be about the average size of an icelandic eruption, the river’s flow could get 10 to 20 times bigger than what is normal during the summer. We cant exclude the possibility of a larger flood though.”
Even so, you still couldn’t say it was a so called disastrous flood. “That kind of flow, even given its size, wouldn’t really be called a disaster. It wouldn’t even be but 1/10th to 1/5th of the flood that happened in Skeiðarársandur in the year 1996.” The jökulhlaup Magnús mentions was a very big one, shattering bridges to the south of Vatnajökull glacier.
Magnús says that an eruption in the glacier wouldn’t release the pressure that might be building up in the volcanoes Katla or Hekla. “An eruption in Bárðarbunga wouldn’t have any effect on such distant volcanoes.”
Over 1.700 quakes have occurred in the area near Bárðarbunga in the past 48 hours. (see image above)
Update 21.08.2014 at 19:50 pm GMT
Three big earthquakes were detected in Bárðarbunga region of Vatnajökull glacier today. The largest quake measured 4 in magnitude and took place at 11:00. Another one was detected around 13:00 and measured 3,8 in magnitude.
According to the Icelandic Met Office, this does not necessarily mean that an eruption is imminent, since the earthquakes are not located where most of the magma is. Evacuation order is still in effect for the area north of Vatnajökull.
Magnus Tumi Gudmundsson, geophysicist at the University of Iceland, said tonight that there was no change in the surface of the glacier.
“We can see from the data collected that there is no flaws or dig or anything like that in the glacier,” says Gudmundsson. “We went over some parts of the area twice because there has been considerable sisemic activity there on Wednesday (20.08.), but we saw no change.”
If there is an eruption Gudmundsson says that it could taket he lava upp to 24 hours to go through the 500 meter thick ice in the glacier in the crack between Bárðarbunga and Kverkfjöll mountains. If there is an eruption in the caldera of Bárðarbunga, Gudmundsson says it would take a very powerful eruption to go through the glacier which is up to 800 meter thick.
Update 22.08.2014 at 15:00 pm GMT
Intense earthquake activity continues at the Bárðarbunga volcano. Since midnight, over 900 earthquakes have been detected in Bárðarbunga. Today three earthquakes exceeding three in magnitude have occurred on the caldera rim of Bárðarbunga, the largest one was magnitude 4. These earthquakes were at depths around 2 – 5 km. They are interpreted as possible adjustments of the caldera due to changing magma pressure. They are not assumed to be the precursor to an imminent eruption, according to scientists at the Icelandic Met Office.
Update 23.08.2014 at 11:10 am GMT
A 25 kilometer long dike intrusion has formed, north and east of the Bardarbunga caldera. Intense seismic activity continues there. Strong earthquakes have been detected in the caldera itself, but they are associated with decompression of the magma chamber beneath the caldera.
According to the Icelandic Met Office there are no signs that seismicity is decreasing. A 25 kilometer long dike has formed in the crust under the Dyngjujökull outlet glacier at 5 – 10 km. depth. Magma is thought to continue to move along the dyke, possibly branching out at the NE end of the dike.
Several strong earthquakes have been detected in the Bárðarbunga itself; the last one, magnitude 3,6, at 07:02 GMT this Saturday morning, 6.7 km ESE of Bárðarbunga. These events are thought to reflect an adjustment of the caldera rim, related to decompression in the caldera since the beginning of the unrest six days ago. 1638 earthquakes has been recorded during the last 48 hours.
Update 23.08.2014 at 14:11 pm GMT
Small eruption has started at crack northeast of Bárðarbunga in Dyngjujökli, according the Icelandic Met Office.