Reykjanes Earthquakes: Uncertainty Phase Declared

The Department of Civil Protection and Emergency Management has declared a phase of uncertainty due to the ongoing earthquake swarm on the Reykjanes peninsula in Southwest Iceland. Six earthquakes over M3 were detected on the peninsula yesterday, with the strongest measuring M4.7. Specialists say earthquakes and uplift in the area are likely signs of magma collecting below the surface. There are no signs an eruption is imminent.

Likely magma is gathering below surface

“We have seen, since before the weekend, indications that expansion and uplift are occurring by Svartsengi similar to what happened in 2020,” Met Office Earthquake Hazards Coordinator Kristín Jónsdóttir told RÚV. “That is we think it is quite likely that we are seeing the beginning of magma collecting below the surface at Svartsengi and it’s of course not unthinkable that could end in an eruption, but it is still much too early to say.”

The 2020 activity Kristín is referring to was a period of uplift (land rise) by Þorbjörn mountain on the Reykjanes peninsula. The uplift ended without an eruption ever occurring. An eruption did occur on the peninsula last year, however, as many readers know, and it was preceded by weeks of powerful earthquakes felt across Southwest Iceland. Volcanologist Þorvaldur Þórðarson has stated there is a 50% chance of another eruption on Reykjanes this year.

Falling objects and landslides

Travellers and hikers on the Reykjanes peninsula are warned to stay away from steep inclines, where earthquakes can cause landslides or rockfall. The Civil Protection Department encourages residents in or near the active are to secure loose objects in their homes that could fall in the event of an earthquake, particularly those that could fall on individuals while they are sleeping. The Civil Protection Department website features earthquake preparedness information in English.

Read more about the geology of the Reykjanes peninsula.

Strongest Earthquake Swarm Since December

Reykjanes

The Reykjanes peninsula in Southwest Iceland experienced its strongest earthquake swarm since December yesterday evening. The swarm began at 9:20 PM last night with an earthquake measuring M3.9. The swarm was already calming down by this morning and there is no sign of volcanic unrest in the area.

The swarm’s first earthquake proved to be its strongest, though six other quakes measuring over M3 were recorded between 9:20 PM and 12:35 AM last night. All of them originated just northeast of Reykjanestá.

“This is a typical swarm in this area, basically considering how they’ve been in the past two years,” Einar Bessi Gestsson, a natural hazard specialist at the Icelandic Met Office, told RÚV early this morning. The earthquake swarm is a fair distance west from the Geldingadalir eruption site, and there are no signs of volcanic unrest.

Einar Bessi says experts will continue to monitor the site using GPS data and satellite images in the coming days.

Earthquake Swarm Intensifies on Reykjanes Peninsula

Keilir

A magnitude 3.7 earthquake was felt across Southwest Iceland, in the Reykjavík capital area, and as far as Borgarnes, West Iceland just before 2:00 AM this morning. Its point of origin was on the Reykjanes peninsula in Southwest Iceland, between Keilir and Litli-Hrútur mountains. The quake is part of an ongoing earthquake swarm on the peninsula, not far from the ongoing Fagradalsfjall eruption.

“The earthquake swarm is still ongoing; the quakes are occurring about one minute apart. The swarm has gotten stronger today than it was yesterday,” Lovísa Mjöll Guðmundsdóttir, Natural Hazard Specialist at the Icelandic Met Office told Iceland Review. The swarm is nothing unusual for the region, according to Lovísa, and it could die out in the coming days or continue for some time.

The earthquakes could, however, be a sign that magma is collecting below ground, but if that is the case Lovísa says it is not near the surface. “The earthquakes are around 5-7km [3.1-4.3mi] deep, so if there is magma it is quite deep underground.” No volcanic tremors have been detected at the site.

Science Board meets today

The Civil Protection Department’s Science Board will meet later today to discuss the ongoing eruption on the Reykjanes peninsula as well as the earthquake activity that woke residents across the region last night. The board will receive the latest satellite images of the area, which should provide more clues as to what is behind the activity. “We’ll have to wait and see,” Lovísa stated.

The Science Board will also review the ongoing eruption as well as activity at Askja crater, where uplift has been occurring since the beginning of August, which could mean magma is collecting below the surface. “The land is still rising and there are earthquake swarms from time to time, but this is all normal activity,” Lovísa stated. “We are continuing to monitor it closely.”

Lava Pools Form and Burst in Geldingadalir

“My feeling anyway is that this eruption could continue for a few years. But of course, we don’t know that for certain. But there’s nothing that’s telling us that this eruption is going to stop tomorrow.” These were the words uttered by Professor of Volcanology Þorvaldur Þórðarson in a RÚV interview yesterday, the day that marked six months since the eruption on Iceland’s Reykjanes peninsula began.

Since it began on March 19, the so-called Geldingadalir eruption has formed new vents, cut off hiking paths, released giant gas bubbles, and filled the surrounding valleys with fresh, black lava. Surface activity has lapsed on several occasions, including earlier this month when one of the eruption’s vents clogged up, but experts say activity below the surface has continued.

Lava from the eruption is now forming pools in Geldingadalir, which occasionally overflow to create beautiful but dangerous streams down into the surrounding valleys. Þorvaldur expects activity to be concentrated in the Geldingadalir valleys in the coming weeks.

“We see that lava pools are building up in Geldingadalir and we of course saw just last week on Tuesday that when these lava pools burst and open up, then the lava can go down, or rather forward, very fast and go much further than under normal circumstances,” Þorvaldur stated. He added that the further south the lava pools are in Geldingadalir, the likelier it is that the lava will flow into Nátthagi valley and from there toward Suðurstrandarvegur road.

Reykjanes Eruption: Giant Gas Bubbles Linked to Fluctuating Activity

Eldgos - Geldingadalir - Reykjanes - hraun

A new crater has formed at the ongoing eruption on Iceland’s Reykjanes peninsula. Professor of Volcanology Þorvaldur Þórðarson told RÚV the new crater appears to be independent from the older active crater. The eruption has been active for nearly five months now and Þorvaldur says it is forming a wide range of lava types, including one he called “toothpaste tube lava.”

Magma chamber at least 15km deep

“Now there seems to be a new crater just outside this crater that has been erupting for the past few months, which we call Crater 5. Whether it is completely connected to this tunnel that feeds the eruption or whether it is a protrusion from the lava pond that is in the crater is not possible to say at this stage. But this seems to be an independent crater that behaves independently, or somewhat independently, of the big one next to it,” Þorvaldur stated.

Experts know little about the magma chamber feeding the eruption, according to Þorvaldur. “We know the magma chamber is there. How wide it is and how long it is, that’s hard to say. But we also know something else, that it reaches all the way down to a depth of 15km [9.3mi], possibly even 17km [10.6mi].”

Cause of fluctuating activity unknown

Lava flowing from the eruption’s craters has reached temperatures of up to 1,240°C [2,264°F], according to a thermometer at the site. Þorvaldur says it has formed all the different types of basalt lava that are known to volcanologists [on land], including smooth pāhoehoe lava as well as rough, jagged ʻaʻā lava (both terms originate in the Hawaiian language), and something he calls “toothpaste tube lava.” Two main factors affect what type of formation results as the lava dries: its viscosity, and the shape of the landscape it flows over.

Since late June, volcanic activity at the eruption site has been fluctuating between active and inactive periods lasting hours or days at a time. Þorvaldur says experts do not know why the eruption is behaving this way but it is connected to the formation of giant gas bubbles. “We get fresh magma coming up. It releases gas into the bubbles and the bubbles expand. We’re talking about bubbles that are 10-20 metres in diameter when they come up. There aren’t just one or two bubbles. There’s a stream of them. That’s what keeps the magma jet activity going in these cycles […] The big question for us is: why is this happening?”

Experts have stated there is no way of knowing how long the eruption will last: it could end at any moment or continue for years or decades.

Read more on the 2021 Reykjanes eruption from Iceland Review Magazine: Ashes to Ashes, Dust to Dust

Reykjanes Eruption: New Vent by Main Crater

Geldingadalir Reykjanes eruption

Lava will begin flowing out of Meradalir valley in two to three weeks if the ongoing eruption on Iceland’s Reykjanes peninsula continues at the same pace, RÚV reports. A new vent opened at the edge of the eruption’s active crater today, and both are now spouting lava from the same source. Volcanic tremors at the site began increasing around 3:00 AM this morning, continuing the eruption’s fluctuating pattern of activity.

Preceded by weeks of strong earthquakes, the Fagradalsfjall eruption began on March 19 of this year. It has been ongoing for nearly five months now, during which lava flow has been relatively small but steady. Volcanologists Þorvaldur Þórðarson and Ármann Höskuldsson were at the eruption site yesterday taking measurements. Ármann stated that he has never seen an eruption like this in Iceland.

“It’s a completely unique eruption that just calmly rises to the surface and nothing seems to affect it. It just takes over the land as it pleases.” Various types of lava can be seen at the site, including smooth pāhoehoe lava as well as rough, jagged ʻaʻā lava (both terms originate in the Hawaiian language).

The Icelandic Institute of Natural History just released a 3D model of the eruption site using pictures taken yesterday. Interested readers can also watch a live feed of the eruption – the crater could be seen bubbling actively at the time of writing.

Reykjanes Eruption: Active Crater Bubbles in New Drone Footage

active crater of the Geldingadalir eruption July 12, 2021

New drone footage of Iceland’s ongoing eruption shows plenty of activity in the crater, which is ejecting lava towards Meradalir valley. If the eruption continues, lava is expected to flow southward from the valley toward the coast. The footage, seen below, was taken by Jóna Sigurlína Pálmadóttir.

https://www.facebook.com/1736063373274429/videos/503091034353510

The footage shows bubbling lava in the crater, which is then ejected through a hole in the crater wall, from which it flows quite rapidly towards Meradalir. Volcanic tremors at the eruption site began fluctuating at the end of June, but have been relatively steady since last weekend. Experts have stated that the eruption could last years or decades but have made it clear there is no way to predict when it will stop.

 

Reykjanes Eruption: Activity Decreases, Lava Flow Continues

volcano eruption Reykjanes

Volcanic activity has decreased significantly at the Geldingdalir eruption on Iceland’s Reykjanes peninsula. The volcanic tremor at the site began fluctuating around ten days ago, dropping five times during that period before activity rose again. According to Geophysicist Magnús Tumi Guðmundsson, however, the lava flow from the eruption does not appear to have decreased.

“It changed of course ten days ago or so and went into this unstable mode, where it has blasted up quite a bit and then been very quiet in between. Now there is a quiet period where there has been very little activity for over two days and the last ten days are a bit calmer than the average has been,” Magnús Tumi told RÚV.

Experts have previously stated that the eruption could last years or decades but have made it clear there is no way to predict when it will stop. According to Magnús Tumi, it’s difficult to say whether this new phase indicates the eruption is coming to an end. “There can be fluctuations in activity. But it seems to be slowing down. It would come as no surprise if it were, as most eruptions in this area don’t get much larger than this. But it’s not possible to confirm anything at this point.”

Volcanic Gases Cause Haze and Breathing Issues

Reykjanes Eruption

Gases from the ongoing eruption on Iceland’s Reykjanes peninsula may lead to fewer sunny days this summer, Vísir reports. Eruption gases have been creating a haze in the capital area in recent days and causing discomfort for people with asthma or other lung conditions. Air quality specialist Þorsteinn Jóhannsson says locals should get into the habit of monitoring air quality in their surroundings.

Though weather has been sunny in the capital area recently, lately the sunshine has been obscured by a mist known as volcanic haze. “Volcanic haze is not the usual ash plume that comes directly from the eruption, which is primarily sulphur dioxide. It can be an old or developed plume that has been floating around for 3-4 days just off the coast and then comes onto land again and then it’s been turned into sulphur particulate matter. That refracts light so it is seen as a haze,” Þorsteinn explains.

According to Þorsteinn, volcanic haze is more common on warm, sunny days and can also boost the formation of regular fog. Though the eruption is on Iceland’s southwest tip, the haze can travel anywhere in the country, such as Akureyri, North Iceland, where it was observed some weeks ago.

Volcanologists have stated the Reykjanes eruption could last years or even decades. “If this eruption persists, we need to put ourselves in eruption air quality gear and keep a close eye on it,” Þorsteinn says. “One can’t recommend running a long race in heavy pollution, it’s usually possible to go between houses, but sensitive people should avoid being outdoors if there is a lot of volcanic haze.”

Air quality in Iceland can be monitored on loftgaedi.is.

Reykjanes Eruption May Have Entered New Phase

Geldingadalir reykjanes eruption volcano

It’s not clear whether the fluctuating activity of Iceland’s ongoing eruption indicates the start of a new phase of activity, says Natural Hazard Specialist Sigurdís Björk Jónasdóttir of the Icelandic Met Office. Since late June, volcanic tremors at the site have subsided for hours at a time before starting up again.

Such a dip in activity occurred yesterday, but it picked up again last night and has been high all night. “The crater is bubbling along and the lava has been flowing vigorously,” Sigurdís told RÚV. She added that it was uncertain whether the oscillations in activity were the start of a new chapter in the eruption. “It is difficult to predict whether this phase has come to stay. We just have to keep an eye on it.”

A fog-like mist blanketed the Reykjavík capital area over the weekend, caused in part by gases from the eruption. Sigurdís points out that residents can monitor air quality on the website loftgaedi.is. The graph below shows tremor activity at Grindavík, near the eruption site, over the past several days.

Veðurstofan.

The Reykjanes eruption has now been active for more than three months. If the steady flow continues, it could eventually form a shield volcano.