Meradalir Eruption Likely Over

Meradalir eruption, August 2022

The Icelandic Met Office is not ready to pronounce the Meradalir eruption officially over, but the dwindling volcanic tremor finally came to a stop at the site on Saturday night. There is no longer visible lava flow from the main crater, and while there is still some activity in the main vent, it is likely already closed.

“The activity at the Meradalir vents and the associated tremor has been dwindling gradually over the last three days, to such a degree that at this moment no fountaining is visible at the vents and the tremor is almost non-existent,” the Volcanology and Natural Hazard Group of the University of Iceland wrote on their Facebook page on Saturday afternoon. “However, there is still steady venting of magmatic gases. This trend in the eruptive behavior is very different from that observed at the end of individual eruption episodes in the 2021 eruption, which were terminated very abruptly. Hence, it is likely that this rather slow and gradual decline in activity is signifying the demise [of] the 2022 Meradalir eruption.”

Disappointment for some, relief for others

The Meradalir eruption began on August 3 around 1:18 pm, not far from last year’s Geldingadalir eruption, on Southwest Iceland’s Reykjanes peninsula. By August 13, lava flow had decreased significantly around 10 days later to about one third of the original rate. Now all volcanic tremor has ceased, and the main vent appears to be closed. In order to formally declare the eruption over, however, there must be no activity at the site for several days or weeks.

While some who had not had a chance to see the eruption yet may be disappointed, residents of the Reykjanes peninsula are likely relieved the lava flow was contained to Meradalir valley, where it did not threaten nearby roads or energy infrastructure. Search and rescue crews who had been monitoring the site and its tens of thousands of visitors are also likely looking forward to some time off.

Volcanologists and geologists have stated that the Meradalir and Geldingadalir eruptions mark the beginning of a new active volcanic period on the Reykjanes peninsula that could last decades or even centuries.

50% Chance of Another Reykjanes Eruption this Year, Expert Says

Geldingadalir eruption lava

Volcanologist Þorvaldur Þórðarson reckons there is a 50/50 chance that an eruption will begin on the Reykjanes peninsula by the end of the year. It could occur on land, like last year’s Geldingadalir eruption, active between March and September of 2021, or out in the ocean near the Reykjanes coast. While last year’s eruption was minimally disruptive to the surrounding area, there is always the possibility that another could cause air pollution, ashfall, or disruptions to international flights through Keflavík Airport, Þorvaldur told RÚV.

Earthquake swarms on Reykjanes

Earthquake swarms occurred on the Reykjanes peninsula last week and over the weekend. The second swarm began on Sunday morning and included two earthquakes over M3 in magnitude. The activity has since calmed down, but Þorvaldur says it’s possible the earthquakes are a sign of magma moving under the surface. There are, however, no signs that an eruption is imminent.

At sea or on land?

Eruptions at sea carry different risks to eruptions on land, according to Þorvaldur. “If it’s a sort of small, neat tourist eruption like the one in Fagradalsfjall then it’s good to have it on land, but if it’s bigger and more powerful, then the situation is different, and there there is maybe more at risk both in terms of lava flow and also in terms of sulphur pollution,” he stated. “There is much more sulphur pollution from eruptions on land simply because eruptions at sea or underwater create a lot of steam, and this steam condenses in the plume and takes out the sulphur. If the eruption is on land then we don’t have so much steam and much less of the sulphur is removed immediately, so it falls to the ground or spreads further and causes pollution. That’s the downside of an eruption on land.”

However, an eruption at sea that breaches the water’s surface could cause significant ashfall on land across the Southwest region, including as far north as Hvalfjörður, Þorvaldur says. He adds that if an eruption does occur, it’s even possible magma would breach the surface in several locations at once.

Experts have stated that the Geldingadalir eruption likely marks the start of a period of increased volcanic activity on the Reykjanes peninsula. Read more about the peninsula’s geology.

Icelandair Cancels Flights Due to Severe Weather


Icelandair has cancelled all flights arriving or departing from Keflavik Airport on Thursday morning, due to extreme weather conditions.

The Icelandic Met Office has issued yellow weather warnings in five regions, starting this evening. According to Birta Líf Kristinsdóttir, a meteorologist at the Met Office, all regions in Iceland will be affected by a deep depression that is forecast to cross the country tonight.

In a travel alert on Icelandair’s website, it says that passengers who experience disruptions due to the cancellations will be rebooked automatically. Instead of having to contact the airline, they will receive a new itinerary via e-mail.

Eruption site closed

The Reykjanes Police District announced earlier today that the Geldingadalir eruption site will be closed to visitors due to extreme weather.

“Travelling in this weather is not advisable. Furthermore, the weather may complicate rescue operations and monitoring in the area,” says in the announcement.

The Met Office has advised travellers to monitor the situation closely. Road closures are common during severe winter storms and driving conditions can be dangerous.

The weather in Iceland has been quite rough during these first days of the year. New Year’s Day was extremely cold and windy in the capital. Two days ago, the eastern region of the country was hit by a storm that caused damage to breakwaters in the town of Vopnafjörður.

MET Office Preparing to Declare Formal End of Eruption

Protective barrriers in Reykjanes

The Icelandic Meteorological Office is preparing to declare the eruption in the Reykjanes peninsula formally over, Fréttablaðið reports. No lava has flowed from craters in the area since September 18.

The longest eruption of the 21st century

On September 16, the volcanic eruption in the Reykjanes peninsula overtook the Holuhraun eruption to become Iceland’s longest-lasting eruption of the 21st century. Two days later, however, lava stopped flowing from the craters; there has been no volcanic activity since.

In late November, the National Police Commissioner – in consultation with the Reykjanes Peninsula Police Commissioner – lowered the Department of Civil Protection and Emergency Response’s Readiness level from “Alert” to “Uncertainty.” On December 3, the uncertainty phase was lifted.

According to Fréttablaðið, the Icelandic Meteorological Office is now preparing to announce a formal end to the eruption, which began on March 19 of this year. As noted in the article, such a declaration is somewhat unusual.

The Reykjanes Peninsula is still active

Despite the uncertainty phase being lifted, the MET Office stressed that it would continue to monitor the Reykjanes peninsula because the region is still volcanically active. Individuals visiting the area are encouraged to be cautious. The lava may still be hot and gas pollution remains a  threat.

“It can take a significant time for the lava to cool. The surface and the craters are still unstable; craters may collapse, fissures may form. Furthermore, gas pollution is expected to continue, which is hazardous to visitors of the area.”

The Fourth Longest Eruption Since the Start of the 20th Century

Geldingadalir eruption lava

Since the beginning of the 20th century, only three volcanic eruptions in Iceland have lasted longer than the one in Geldingadalir, according to geologist Sigurður Steinþórsson. Although scientists have yet to declare the formal end of the eruption, no lava has emanated from fissures for almost a month.

“You should’ve had something else to drink”

It was on the evening of Friday, March 19, when the paramedic Einar Sveinn Jónsson received a call from Bogi Adolfsson, head of the Grindavík search-and-rescue chapter. Bogi, having noticed a “yellow glow” emanating from behind the mountains, and being familiar with the view from his colleague’s home, asked Einar Sveinn to step outside and take a closer look.

Einar Sveinn had been hosting a dinner party for a few friends and stole away to follow his companion’s curious instructions. Having admitted to Bogi that that “yellow glow” could not be attributed to the “lights from Vogar” (a neighbouring town), he returned inside with a chill running down his spine. His wife Erna, noticing that something was awry, and drinking a canned cocktail called Eldgos (Icelandic for “Volcanic Eruption”), asked him what was the matter.

“You should have had something else to drink,” Einar Sveinn responded before pantomining an eruption with his hands; the volcanic eruption in Geldingadalir had officially begun.

A period of 183 days

“The eruption in Geldingadalir,” writes Sigurður Steinþórsson, in an article on Vísindavefurinn published yesterday, “must be considered relatively lengthy when compared to other continuous eruptions in the 20th and 21st centuries.” In the article, Sigurður, professor emeritus of geology at the University of Iceland, maintains that only three other eruptions since 1900 have lasted longer than the one in Geldingadalir (183 days): the Hekla eruption between 1947 and 1948 (390 days), the Surtsey eruption between 1963 and 1967 (1290 days), and the Krafla eruption between 1975 and 1984 (3180 days).

Sigurður assumes, as a premise for his article, that the eruption in Geldingadalir ended on September 18, the day when lava ceased issuing forth from fissures in the valley. Scientists have, however, yet to declare the eruption as formally over. (The eruption has seen a hiatus in the past but never for this long.)

“It might seem that the Hekla eruption between 1980 and 1981 was longer,” Sigurður writes “but it was actually two short eruptions (three and seven days respectively), with a seven-month hiatus between them.” Referring to the Krafla eruption, Sigurður also observes that that eruption was actually “a series of smaller eruptions separated at length with periods of inactivity,” suggesting that only the Hekla eruption between 1947 and 1948 and the Surtsey eruption between 1963 and 1967 lasted longer than the one in Geldingadalir.

The four phases of the eruption

As noted in an article on RÚV yesterday, the Faculty of Earth Sciences at the University of Iceland has divided the eruption in Geldingadalir into four phases. The first phase lasted approximately two weeks and was characterized by rather steady lava flow (an average of 6 m3/s). The second phase also lasted for two weeks and was marked by the emergence of new fissures north of the original caldera, with lava flow being quite variable (between 5-8 m3/s. The third phase lasted for two and a half months, with the volcanic activity confined to a single crater and flowing into Geldingadalir, Meradalir, or Nátthagi at a rate of approximately 12 m3/s. The final phase began at the end of June and was characterized by sporadic lava flow (8-11 m3/s).

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 Now Longest of the Century in Iceland

Eldgos - Geldingadalir - Reykjanes - hraun

It’s been 181 days since the Geldingadalir eruption began on Iceland’s Reykjanes peninsula on March 19, 2021. That means it has now overtaken the Holuhraun eruption to become Iceland’s longest-lasting eruption of the 21st century. It still shows no signs of stopping, and experts have stated that the eruption could last years or even decades.

The South Iceland Volcano and Natural Hazard Group reported the milestone on its Facebook page. “Surface activity in Geldingadalir has lapsed a few times but there are no signs that the eruption is ending soon,” the post states. The latest of these lapses lasted 8.5 days and ended on September 11, when surface activity at the eruption resumed once more. The University of Iceland’s Volcanology and Natural Hazard Group confirmed that this lapse was caused by a clogged vent.

“It is evident that the opening that fed vent 5 clogged up, which prevented magma from entering the vent over this time period,” a Facebook post from the group reads. “This also halted formation of very large gas-bubbles, which explains the drop in tremor intensity. Yet, periodic but weak tremor episodes, steady outgassing from the vent, incandescent lava in skylights above lava tubes and newly scorched vegetation along the lava margins in Geldingadalir is a testimony that magma was streaming up through the conduit towards the surface during this 8.5 day-long pause in the surface activity.”

Route A at the eruption site was closed yesterday after lava that had been pooling in Geldingadalir began streaming across the route and an evacuation of the area was carried out. The eruption site is open once more today and conditions are good. Over 288,000 people have visited the eruption site since the eruption began last March.

The Geldingadalir eruption is only three days away from its six-month anniversary, but it’s still far from becoming Iceland’s longest-lasting eruption of all time. The Surtsey eruption is considered the longest eruption in Iceland’s history, lasting from November 1963 until June 1967 and forming the island of the same name.

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

New Lava Vandalised by Visitors

Geldingadalir eruption lava

Visitors to the ongoing eruption on Iceland’s Reykjanes peninsula are urged not to walk on the new lava at the site or throw rocks onto it in a notice from the Environment Agency of Iceland. New lava is a unique geological formation that is protected under the Nature Conservation Act and throwing rocks on it or vandalising it in any other way is considered a violation. The lava’s black surface may appear solid but the top layer can be quite thin and hiding flowing, molten lava underneath.

Hot lava up to 1200°C

Visitors to the eruption may have noticed the heat that emanates from the site, even from the edge of lava fields that appear solid. “The lava is extremely hot and can take a long time to cool, especially as the eruption can continue even though we don’t see movement in the crater itself,” the Environment Agency notice states. “The lava then flows under the black shell in lava caves or domes. The lava shell can easily break and underneath it there can be lava up to 1200°C [2192°F].” Not only is walking on the lava dangerous, it can damage the formations, which are protected.

Environment Agency rangers are manning the start of the hiking trail to inform and educate guests on how to enjoy the eruption in a safe and respectful way. “The lava from the volcanoes in Geldingdalir is a unique geological monument that we need to respect and protect,” the notice states. “There we are probably witnessing the first shield volcano eruption in Iceland since the country was settled.”

Ploughed illegal path through lava

Rocks and pedestrians are not the only damage that the active lava field has faces since the eruption began last March 19. Last week, police stopped a man that was ploughing a path through the lava without a permit. The man is believed to have been sent by landowners but Fréttablaðið reported there was no licence for the operation and authorities were not informed.

The ploughman had dug a path through the lava field along so-called Hiking Path “A,” which was cut off by lava in June, closing off a popular look-out slope near the eruption’s active crater. Authorities have put up a sign to inform visitors that the path is closed, but expressed concern that some visitors might take it anyway. “It’s very dangerous to let people into a closed area like this,” stated René Biasone of the Environment agency. “If people walk in there they’re entering an area that is surrounded by lava. If the lava starts flowing again where it was ploughed they will be closed in.”

New crevasses on former look-out spot

The former look-out slope is also unsafe for another reason: the Icelandic Met Office reported yesterday that new crevasses have formed on the slope, which appear to have formed in the past two weeks. The crevasses were are probably caused by tensile stress and may have been caused by small earthquakes or land movement due to changing pressure of magma below the surface.