Large Earthquake Hints at Bárðarbunga Unrest

Vatnajökull Grímsfjall Grímsvötn Bárðarbunga Kverkfjöll Jöklar Jökull Vísindi

An earthquake measuring at 5.4 on the Richter scale took place at Bárðarbunga stratovolcano under Vatnajökull glacier this morning. Seismic activity of this magnitude could mark the beginning of a new era of unrest in Bárðarbunga, the first since the Holuhraun eruption in 2014 to 2015, Mbl.is reports.

Pressure building

The earthquake is the largest in the area since 2015. Hildur María Friðriksdóttir, a specialist at the Iceland Meteorological Office, said that crustal movement by Bárðarbunga increased at the beginning of last year, but did not result in increased seismic activity until February this year. “This could be the beginning of a process that could take years, but there is evidence of pressure building in the area,” she said.

Situation monitored

The Met Office will continue to monitor the situation, but Hildur María said that no response by the authorities is necessary at this time. She added that many large earthquakes were detected before, during and after the Holuhraun eruption.

The earthquake this morning was followed by an aftershock that measured 3 on the Richter scale, but Bárðarbunga has been quiet since then.

M4.9 Earthquake in Bárðarbunga Caldera Caused by Magma Intrusion

A lake on top of Bárðarbunga on Vatnajökull glacier.

A strong earthquake occurred this morning in Bárðarbungacaldera located on the Vatnajökull glacier. The earthquake measured M4.9 and was felt as far away as Akureyri. Kristín Jónsdóttir, head of the Icelandic Met Office’s Volcanoes, Earthquakes, and Deformation Department, told RÚV the earthquake was caused by a magma intrusion, but there are no indications the magma is on its way up to the surface.

Land rise has been occurring at Bárðarbunga since the end of the Holuhraun eruption in 2015. Kristín says there are no indications the current activity is related to the land rise and melting ice currently occurring at Askja volcano.

There are also no indications an eruption from Bárðarbunga is imminent, Kristín says. “Bárðarbunga could be in this phase, this magma accumulation phase, and then we get these strong quakes at certain intervals, for decades.”

Earthquakes by Bárðarbunga, Mýrdalsjökull

earthquakes iceland

Around 1 AM this morning, a magnitude 3.8 earthquake was recorded by Bárðarbunga, a volcanic system underneath Vatnajökull.

A relatively inactive system, Bárðarbunga last erupted in 2014 in the Holuhraun eruption, which caused relatively little disruption except for decreased air quality in the surrounding area.

The same fissure system has also seen significant seismic activity to its southwest, in the highland area between Vatnajökull and Mýrdalsjökull. Significant quakes (magnitude 3.0) were also detected by Góðabunga last night, a volcanic system under Mýrdalsjökull, a glacier on the South Coast of Iceland. These quakes occurred approximately 20 minutes after the activity under Bárðarbunga.

Earthquakes by Mýrdalsjökull Likely Caused by Warm Weather

Reports from the Meteorological Office indicate that the recent quakes on the South Coast have not affected settlements in any way.

Several other significant quakes were detected by Mýrdalsjökull on Saturday night, November 26. Nine earthquakes were recorded around 4 AM, with the largest recorded on Sunday at 3.4.

Lovísa Mjöll Guðmundsdóttir, natural scientist at the Meteorological Office, stated to RÚV that the recent activity can be attributed to warmer-than-average weather. Glacial melt and flooding atop Iceland’s many volcanic systems have been known to trigger both seismic and volcanic activity, as often happens in the Grímsvötn system.

The most recent quakes underneath Mýrdalsjökull are attributed to activity in the Katla system.

“There are changes in tension when there are warming periods, and it has been unusually warm for this time of year,” stated Lovísa. “It often comes in pulses like this, but it is often a long time between these periods.”

See the Meteorological Office of Iceland for more information.

 

 

M4.9 Earthquake in Bárðarbunga

An M4.4 earthquake occurred in the northern part of Bárðarbunga shortly after noon yesterday. Less than half an hour later, an earthquake measuring M4.9 was detected.

Bárðarbunga is an active volcano that last erupted in 2014, but according to Iceland‘s Meteorological Office, there are no signs indicating an imminent eruption. A notice from the Met Office stated that the last quake of this size was detected in January 2020 and before that in January 2018. Quakes of this size are not uncommon in Bárðarbunga; since 2015, about 50 such quakes have been detected in the area.

Earthquake at Bárðarbunga Caldera

Vatnajökull Bárðarbunga

An earthquake occurred under the Bárðarbunga caldera at 7:20 am on Saturday morning, RÚV reports. The quake was measured a 4 and while it isn’t uncommon for earthquakes to occur in the area, Saturday’s incident is notable as Bárðarbunga, a stratovolcano located underneath Iceland’s largest glacier, Vatnajökull, is the second largest volcano on the island—and the most active.

See Also: Bárðarbunga Calming Down or Preparing for Next Eruption

The earthquake started 4.6 km [2.85 mi] northeast of the volcano, at a depth of 1.3 km [8.1 mi]. Afterwards, the Met office only detected a very little aftershock activity.

The last time major unrest occurred at Bárðarbunga was in 2014, when magma streamed out of the chamber under the volcano and flowed almost 40 km [24.8 mi] to the Holuhraun lava field, where there was an eruption. The eruption lasted almost six months.

Geoscientists have been keeping a close eye on Bárðarbunga of late. In July, it was reported that the volcano has been expanding and it could be due to magma accumulation or recovery from its last eruption. Geophysicist Páll Einarsson told reporters, however, that the powerful earthquakes underneath the volcano this summer were likely due to land rise and that an eruption did not appear to be imminent.

Bárðarbunga Calming Down or Preparing for Next Eruption

Vatnajökull Bárðarbunga

Bárðarbunga volcano has been expanding and it could be due to magma accumulation or recovery from its last eruption in 2015. Geophysicist Páll Einarsson told Morgunblaðið that recent powerful earthquakes underneath the volcano are likely due to land rise. An eruption is not imminent, however.

Two earthquakes measuring M3.9 and 4.5 occurred at the volcano site two days ago, according to the Icelandic Met Office. According to Páll, it’s difficult to say what the activity could indicate in a larger context. If Bárðarbunga is preparing for an eruption, then the earthquakes would be a sign of that. An eruption is not, however, expected in the near future.

Read More: The 2014 Eruption in Holuhraun

Bárðarbunga is a stratovolcano located underneath Iceland’s largest glacier, Vatnajökull. The volcano’s last eruption was the Holuhraun eruption in 2014-2015.

Fourth-Largest Earthquake in Bárðarbunga Since 2015 Eruption

Vatnajökull Bárðarbunga

An earthquake of magnitude 4.8 occurred at 3.54am this morning at the Bárðarbunga caldera in Iceland’s Highland. About a dozen aftershocks followed in its wake. The earthquake is the fourth largest in the area since the months-long Bárðarbunga eruption in 2014-2015. Experts say, however, there is no volcanic unrest in the area.

Elísabet Pálmadóttir, a geohazard specialist at the Icelandic Met Office, says it is common for Bárðarbunga to have isolated strong earthquakes like the one this morning. Such an earthquake occurred on January 5, with no follow-up activity. “We sometimes get earthquakes that are over M4, and then nothing else happens. Bárðarbunga often behaves like that.” Elísabet assures there is no sign of volcanic unrest in the area. “Nothing like it.”

Earthquake was larger than initial data suggested

The earthquake was larger than initial measurements showed. “We have an automated system that analyses earthquakes in real time and gives us a magnitude, but it was too low in relation to other data we were seeing, so it was obvious it had been much bigger. So we did the analysis again and got the magnitude 4.8, which makes it the fourth largest earthquake since the 2015 Bárðarbunga eruption. Since then there have been 12 or 13 small aftershocks, maybe around magnitude 1.”

Clear signs are likely if eruption is imminent

Magma is currently accumulating underneath the caldera, part of its regular activity. “When the eruption ended in 2015, then magma started accumulating again, in preparation for the next eruption, whenever that will be,” Elísabet explains. In 2014, seismic activity in the region gave warning of an imminent eruption around two weeks before it occurred. “Hopefully we get a clear sign beforehand like we got last time. We expect a bit of a heads up, maybe a few weeks in advance.”

Powerful Earthquake at Bárðarbunga

The green star marks the location of the 4.8 earthquake.

A powerful earthquake measuring 4.8 occurred on the northern rim of the Bárðarbunga volcano in the early hours of Friday morning, RÚV reports. The initial earthquake was followed by three aftershock quakes measuring 3.5, 3.7 and 2.8.

Earthquakes have shaken Bárðarbunga since the end of its most recent eruption, which began in August 2014 and ended in February 2015. Einar Hjörleifsson, the Icelandic Met Office’s natural disaster expert says these eruptions have been getting larger as they’ve gone along, but this is only natural as the volcano recovers from its immense eruption.

At the time of writing, there were no signs of volcanic unrest at Bárðarbunga, says Einar, but any developments will be closely monitored going forward.