Magma Likely Collecting Under Reykjanes Again

Increasing uplift (land rise) has been measured on the Reykjanes peninsula since the beginning of April, a sign that magma is collecting below the surface. There are no indications that an eruption is imminent, however. The peninsula has been the site of Iceland’s two most recent eruptions, in 2021 and 2022.

Magma far below the surface

Land on the Reykjanes peninsula has risen between 2 and 2.5 centimetres (around one inch) since the beginning of April, Hildur María Friðriksdóttir, a natural hazard specialist at the Icelandic Met Office told RÚV. “What we’ve been seeing now is steady uplift by Fagradalsfjall [the site of the 2021 and 2022 eruptions]. We aren’t seeing any recent changes or anything sudden. We are seeing uplift which is probably due to magma that is collecting again beneath the site. It’s at a significant depth. The situation is stable at the moment.”

First eruptions in nearly 800 years

An eruption began on the Reykjanes peninsula on March 19, 2021, the first in the area for nearly 800 years. It lasted around six months, until September 2021. It was followed by another, though shorter, eruption at the same location in 2022, lasting just over two weeks. Experts have stated that these eruptions likely mark the beginning of a more active volcanic period on the peninsula.

Familiar activity, but no indications eruption is imminent

Both the 2021 eruption and 2022 eruption were preceded by uplift as well as strong earthquakes felt across Southwest Iceland and the capital region. An M 3.2 earthquake occurred on the Reykjanes peninsula, by Kleifarvatn lake, on June 28. Hildur says, however, that earthquake activity has been fairly stable on Reykjanes recently and it is difficult to say whether there will be another eruption on the peninsula, or when. “There is nothing currently that indicates an [imminent] eruption. I don’t dare to promise anything but there’s nothing that indicates an eruption as it stands.”

Read more about the geology of the Reykjanes peninsula.

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

Little Change in Reykjanes Eruption Activity

Geldingadalir eruption Reykjanes volcano

The ongoing eruption on Iceland’s Reykjanes peninsula was visible from the capital area last night. Natural Hazard Specialist Böðvar Sveinsson of the Icelandic Met Office says the eruption has continued its recent pattern of low activity for 7-13 hours followed by higher activity for a similar length of time. Though it may appear to observers that there are new vents near the active crater, they are likely just holes connected to the main crater rather than independent channels, Böðvar told RÚV.

Lava from the eruption is mostly flowing eastward into Meradalir valley. Böðvar says it has likely been flowing in that direction for some time but has not been visible. This could be because the flow was underneath solidified lava, or because weather conditions have hampered visibility in recent days.

The eruption began on March 19, 2021 and has now been active for more than four months. Experts have stated that it is impossible to say how long it could last, but it could be years or decades. If the eruption continues for an extended period it could form a gently-sloping shield volcano.

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.

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

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 The graph below shows tremor activity at Grindavík, near the eruption site, over the past several days.


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

Reykjanes Eruption: Road Sacrificed, Town Protected

Geldingadalir reykjanes eruption volcano

Icelandic authorities will not attempt to divert lava from the ongoing eruption in Geldingadalir away from the adjacent Suðurstrandarvegur road. The eruption has been ongoing for more than three months now and its growing lava field is expected to reach the road in one to three weeks. Efforts will instead be focused on protecting the nearby town of Grindavík and Svartsengi power station if necessary.

“We’ve had many meetings over the past days and weeks and assess whether it’s feasible to protect Suðurstrandarvegur,” Fannar Jónasson, Mayor of Grindavík, told RÚV. “After a thorough review it was decided that it wouldn’t work, both for technical reasons, due to time, and not least due to the cost.” Fannar says authorities are now looking further ahead to see what infrastructure will need protecting if the eruption continues for many more months. “If it continues for a few months or years we might have to respond so it doesn’t flow to Svartsengi [power station] or even Grindavík. We want to have enough time to prevent that and create powerful barriers. That wouldn’t happen for a long time but structures are being designed nevertheless that would provide protection in that case.”

While geologists say there is no way to predict how long the Reykjanes eruption will last, several have stated that it could be a shield volcano in the making. Shield volcanoes are formed by long, slow eruptions like the one in Geldingadalir where lava forms a gently sloping volcano over time. Such eruptions have rarely occurred in Iceland since the end of the Ice Age but they can last years at a time.

Reykjanes Eruption: Lava Cuts Off Main Hiking Path

lava geldingadalir eruption volcano reykjanes

Lava is now flowing across the main hiking path to the Geldingadalir eruption in Iceland, which has been ongoing for nearly three months. Both of the marked paths to the eruption’s active crater were closed yesterday after lava began flowing across the main trail. The secondary trail, which is open today, is more challenging for hikers, as it’s both steeper and slightly longer. Vísir reported first.

Third Path Being Marked

The secondary path, known as trail B, is open to visitors today. Gunnar Schram, Chief Superintendent of Suðurnes Police stated the path is suited to more experienced hikers than trail A, which remains closed. Authorities are currently marking a third, new trail to the eruption and trail B will remain open to the public until it is ready.

For less experienced hikers, Gunnar suggests visiting Nátthagi valley, which is being filled with lava from the eruption. “It’s quite an experience to walk into Nátthagi, where the lava flows down into the valley,” he stated.

Located on the Reykjanes peninsula, the eruption in Geldingadalir began on March 19 and shows no signs of stopping. Experts say there is no way to predict how long the activity will last.

Reykjanes Eruption: Most Lava Flow Beneath the Surface

Most of the lava flowing from the Geldingadalir eruption is below the surface and entirely hidden from view. The main active crater is slowly closing up as lava accumulates and cools around the opening. The eruption seems to be developing into what’s known as a shield volcano, a formation created by lava flowing slowly over a long period. The eruption has become a popular tourist site and authorities have already approved the preparation of a new hiking path as lava is expected to flow across the one currently used by visitors.

The Geldingadalir eruption began on Iceland’s Reykjanes peninsula nearly three months ago on March 19, 2021. Geologists have identified three distinct periods of activity since magma broke the surface. During the first two weeks, the eruption had a steady though slightly diminishing flow that started at around 7-8 cubic metres per second and slowed to 4-5 cubic metres per second. The second period began in April, and was characterised by new vents opening to the north of the first craters and a flow of 5-8 cubic metres per second. The third period encompasses the past seven weeks, during which the lava flow has been emerging from a single, large crater and has increased from 5-8 cubic metres per second to as much as 13.

“Now the crater is closing little by little. Especially this channel, it’s being covered up bit by bit. Then it gushes over and that just adds to the covering,” Þorvaldur Þórðarson, Professor at the University of Iceland’s Institute of Earth Sciences (University of Iceland) told While he refrained from calling the eruption a shield volcano, he did admit that activity was pointing in that direction. “It’s approaching that. It hasn’t quite become one yet but it’s going in the right direction.”

Read More: Long Eruption on Reykjanes Could Form Shield Volcano

New Hiking Path in the Works

Since the eruption began, Search and Rescue crews have been monitoring the area to ensure visitor safety. Authorities have also created temporary parking lots at the site and marked a hiking path. The end of the path is now inaccessible as lava has surrounded what was once the main lookout over the erupting crater. Bogi Adolfsson, director of the Þorbjörn Search and Rescue team in Grindavík says the lava flow is expected to flow over more of the current hiking path and authorities have approved the preparation of a new trail to the eruption which will become the main path.