Land Continues to Rise at Svartsengi

Art Bicnick. The 2024 Sundhnúksgígaröð eruption

Land rise (uplift) continues at Svartsengi on the Reykjanes peninsula, above the magma chamber that is feeding the ongoing eruption. Experts say new fissures could open in the area with little or no notice. While lava flow from the ongoing eruption has slowed, it could continue for some time.

Uplift at Svartsengi has continued at a steady rate for weeks, according to the latest notice from the Icelandic Met Office. That means that pressure is continuing to build up in the magma chamber below. Earthquake activity at Sundhnúksgígaröð has also increased, likely a sign of pressure being released in and around the magma tunnel at the site of the ongoing eruption, which began on March 16.

A new eruption may occur

Data and modelling show considerable uncertainty about whether the ongoing activity on Reykjanes will lead to another eruption. According to the Met Office, there are two likely scenarios. Firstly, new fissures may open up in the area between Stóra-Skógfell and Hagafell and/or the current eruption vent could grow due to a sudden increase in lava flow. That could happen with very little or no notice.

Read More: The Reykjanes Eruptions

Secondly, the magma flow from the magma chamber under Svartsengi to the active crater on the Sundhnúksgígaröð could gradually increase until there is a balance between the inflow of magma into the magma chamber and the outflow from there to the surface.

The volcanic activity does not impact travel to and from Iceland and the hazard assessment for the area remains unchanged.

Tourists and civilians are asked to stay away from the area.

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Iceland’s Reykjanes Peninsula Likely to Erupt Again Soon

svartsengi power plant reykjanes

Magma is collecting below Iceland’s Reykjanes peninsula again and experts say another eruption could happen at any time. The land by Svartsengi has now risen more than it did before last month’s eruption. The speed of uplift has also increased again, after slowing down last week.

Magma chamber refilling

Following two months of earthquakes and land deformation, Iceland’s Reykjanes peninsula experienced a short but powerful eruption from December 18 to December 21. According to Benedikt Ófeigsson, Coordinator of Deformation Observation at the Icelandic Met Office, the magma chamber beneath Svartsengi has now replenished 75% of the magma expelled by the December eruption.

These developments indicate that another eruption is on the way, Benedikt told RÚV.  The most likely location is the Sundhnúkur Crater Row, between Stóra-Skógfell and Hagafell mountains. According to Benedikt, the eruption could begin there “at any time.”

Blue Lagoon remains open

An overnight evacuation order remains in effect for the nearby town of Grindavík (pop. 3,600). The town was evacuated on November 10 due to powerful earthquakes that damaged roads, homes, and infrastructure in and around the community.

The nearby Blue Lagoon was reopened to visitors on Saturday. Benedikt says an eruption is not likely to occur in the area around the lagoon. “So even if an eruption begins, there will most likely be plenty of time to evacuate people.”

The Reykjanes peninsula, the location of Keflavík International Airport and a stone’s throw from Iceland’s capital, Reykjavík, has entered a period of increased volcanic activity that could last hundreds of years. The four eruptions that have occurred on the peninsula since 2021 have not impacted infrastructure or flights. The earthquakes and deformation preceding the December 2023 eruption, which caused damage in and around Grindavík.

Land Rising Faster on Reykjanes than Before Past Eruptions

Grindavík - Þorbjörn

The land on Iceland’s Reykjanes peninsula has risen some 3 cm [1.2 in] since October 27, indicating an eruption might be on the way. Uplift (the scientific term for this geological activity) has occurred before all three eruptions on Reykjanes in the past three years. While there are no indications that an eruption is imminent, the Department of Civil Protection and Emergency Management has declared an uncertainty phase on the Reykjanes peninsula.

Earthquakes and faster uplift

A powerful earthquake swarm began on the Reykjanes peninsula on the night of October 24 just north of the town of Grindavík. The most powerful earthquakes at the start of the swarm measured M3.9 and M4.5. More than 7,000 earthquakes have been detected in the area since, including an M5.0 earthquake on October 27.

On October 27, the land in the area began to rise, indicating a magma intrusion in the earth below. This is the fifth time that uplift is measured at the location since 2020. The rate of uplift is faster than uplift that occurred in 2020 and 2022 in a similar area. All three eruptions that have occurred on the Reykjanes peninsula in the past three years were preceded by earthquakes and uplift.

Land rise close to Blue Lagoon

The midpoint of the uplift is some 1.5km to the northwest of Þorbjörn mountain, near the Blue Lagoon. The Blue Lagoon’s Director of Sales, Operations, and Services told RÚV that the company is meeting with authorities daily to monitor the situation and has updated their contingency plans. The temperature of the water in the lagoon is monitored regularly and no changes have been detected.

More eruptions can be expected on Reykjanes

In March 2021, an eruption began on the Reykjanes peninsula following a period of nearly 800 years with no eruptions in the area. That eruption lasted around six months and was followed by two shorter eruptions in 2022 and 2023. Geologic activity on the Reykjanes peninsula is characterised by seismic periods lasting 600-800 years, alternating with volcanic periods lasting 400-500 years and experts have stated that more eruptions can be expected on the peninsula in the coming decades. None of the three recent eruptions have impacted inhabited areas or infrastructure.

Land Rises Four Centimetres on Reykjanes

Grindavík - Þorbjörn

The land around Svartsengi, on the Reykjanes peninsula, has risen 4 centimetres since April 21. The uplift is most likely due to a magma intrusion 4-5km below the surface. Satellite images published by the Icelandic Met Office indicate the intrusion is 7-8km long and stretches west of Þorbjörn mountain and underneath Svartsengi Power Station. An earthquake swarm is ongoing at the site, but there is no sign of volcanic unrest.

These geological events are reminiscent of landrise that occurred in the area in 2020. While in that instance, the magma that was collecting underground never reached the surface, a volcanic eruption did occur nearby on the peninsula in 2021, at Fagradalsfjall. While the 2021 eruption was far from infrastructure, the growing magma intrusion is located underneath a geothermal power plant, which is at risk of damage if magma reaches the surface.

Residents of the nearby town of Grindavík were invited to a town hall meeting yesterday evening to discuss the geological activity and go over preparedness in the case of an eruption. 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 website features earthquake preparedness information in English.

Experts have stated that it is too early to say whether the activity will result in an eruption.

The Department of Civil Protection and Emergency Management has declared an uncertainty phase in the area and the aviation code for the area has been changed to yellow.

Uplift on Reykjanes Peninsula

Land has started rising again on the Reykjanes peninsula, RÚV reports. The uplift has been detected north of Mt. Keilir and south of the Fagradalsfjall eruption site. The land around Fagradalsfjall fell during the eruption itself, most likely because of the magma streaming out of the chamber beneath the surface.

According to GPS measurements, land fall began to subside at the end of August and then rise again around the middle of September. The uplift is, however, minimal: only one to two centimetres at the highest points.

According to the Met Office’s models, the magma accumulation deep within the earth is the most likely cause of the uplift, although scientists also believe that it is connected to a month-long wave of seismic activity that began at the southern end of Keilir at the end of September. No dislocation has been observed on the surface as of this time, which might mean that magma is getting closer to the surface.

See Also: The Fourth Longest Eruption Since the Start of the 20th Century

Magma accumulation under volcanic systems sometimes occurs after eruptions. As such, the current uplift is not necessarily an indication that magma will move toward the surface in the near future. It’s possible that this process would instead take years or even decades, although that is difficult for scientists to predict with much accuracy.

There has been no lava flow at Fagradalsfjall since September 18. Gas emissions are still being detected at the eruption site, but only in very small quantities.

 

Eruption Still a Possibility at Askja

Askja volcano iceland

The Icelandic Met Office is closely monitoring uplift at Askja volcano in the Central Highland. Benedikt Gunnar Ófeigsson, a deformation scientist at the institution, told mbl.is that it is not possible to rule out an eruption at the site. The land at Askja has risen 15 centimetres since the beginning of August, movement that is most likely explained by magma accumulating below the surface.

Askja is located in Iceland’s Central Highland, far from inhabited areas. Over the last 7,000 years, its eruption frequency has been around 2-3 eruptions per 100 years. The last eruption at the site occurred in 1961: it was a moderate eruption that produced about 0.1km3 of lava.

Though Benedikt states that the uplift at Askja may still lead to an eruption, he added that it was too early to say when a potential eruption would occur. An uncertainty phase is active in the area.

Earthquake Swarm Near Þorbjörn

Grindavík - Þorbjörn

Numerous earthquakes were recorded just west of the volcano Þorbjörn, near the village of Grindavík in South Iceland on Thursday, RÚV reports.

An earthquake measuring 3.3 was recorded just before 5pm on Thursday and was followed by another measuring 3.2. Both quakes originated not far from the volcano Þorbjörn, which experienced another earthquake measuring 5.2 last week. Land rise was detected around Þorbjörn on Wednesday but its progress has been quite slow. The recent rise and earthquake activity are being monitored by scientists.

A number of aftershocks were measured around Þorbjörn after Thursday’s quakes and were felt as far as the capital area, almost 50 km [31 mi] away.

“There’s an earthquake swarm in progress and we’re trying to figure out what’s going on,” remarked Kristín Jónsdóttir, the Icelandic Met Office’s Earthquakes Hazards Officer. The quakes are shallow, she continued, and scientists cannot currently rule out the possibility that they are somehow related to geothermal energy production at the HS Orka power plant nearby. If the quakes are not connected to geothermal energy production, the next step will be to determine if magma has been collecting in the area, which scientists think is likely.

When asked, Kristín said that there will likely be more earthquakes around Grindavík in the coming days.

Land Rising Again Near Volcano Þorbjörn, But No Volcanic Unrest

Grindavík - Þorbjörn
Land rise has begun again in the near surroundings of volcano Þorbjörn near Grindavík. As of yet, there are no imminent signs of volcanic unrest. This follows an earthquake that rattled the Reykjanes peninsula on March 12.
Meteorologists have kept a keen eye on the area following initial land rise early in the year, which had slowed down in February. The land rise now is happening at a slower pace than the original land rise in January, but it is rising in the same area as the initial rise. The science council of the Department of Civil Protection and Emergency Management will meet to discuss the matter next week.

Eruption not imminent

Results from crust measurements have been clarified in the last couple of days. It’s now clear that expansions that cause land rise has begun anew in the area surrounding Þorbjörn. This is confirmed both by GPS measurements in the area as well as satellite data. Scientists from the Icelandic Met Office, The Institute of Earth Sciences of the University Iceland as well from the Iceland GeoSurvey, met this morning to analyse the newest measurements and data.

“The land rise this time around seems to be quite slow, considerably slower than in January. 20mm is really quite a small land rise and it is difficult to analyse such small changes with the technology at hand. In such cases, we need to collect data for several days to confirm that land rise has taken, or is taking place,” said Benedikt Gunnar Ófeigsson, a meteorologist at the Icelandic Met Office.

“Even though we’re seeing signs of land rise beginning again, it does not mean that the course of events surrounding Þorbjörn is catching speed, nor that an eruption will begin soon. It’s a known quantity for magma to gather for a long time, months, even years before it comes to an eruption,” said Kristín Jónsdóttir, a project manager at the natural disaster shift at the Icelandic Met Office. “Events, like we’re witnessing in the Reykjanes peninsula, can take quite a long time and differentiate, as volcanic activity dies down for a short time without it being fully over.”

Land Rising Due to Melting Glaciers

The land around Höfn in Hornafjörður is rising rapidly due to the melting of the glaciers in the surrounding area. Normally, the most highlighted issue connected to global warming is the rise of sea levels which threatens communities and land close to sea level. In this case, the exact opposite is true as the land is rising to the tune of one centimetre per year.

“These are profound changes, especially in the area around Vatnajökull glacier,” says Páll Einarsson, professor emeritus in geophysics. The land in the East Iceland area is rising due to the rapid changes taking place for glaciers in the country. “It’s already had considerable effects in Höfn in Hornafjörður. There, the land is rising one centimetre per year,” Páll stated. The municipality of Höfn has invested significantly in construction projects to put a halt to the land-rise, or at the very least lessen its effects. “Hornafjörður is a clear example of the effect of climate change. In Höfn it’s a question of life or death for the town. If land rises significantly, the fjord can start to be impassable for ships.”

Hornafjörður became passable for ships in 1930 when the land had sunk enough for ships to be able to enter the natural lagoon in the area. Before that, a town was situated in nearby Papós í Lóni. That town became deserted as the town of Höfn grew in size. Vatnajökull glacier is the largest glacier in Iceland, covering 8% of the country’s total surface area.

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The area around Höfn í Hornafjörður is rising at a rate of one centimetre per year due to the melting of nearby Vatnajökull glacier.

The Icelandic Geological Survey measures both land rise and the sinking of land each year. “When the glaciers melt and lose weight, the earth’s crust rises. The foundation, the lower part of the crust, as well as the mantle, are soft below Iceland and gives way. It was profound close to the end of the ice age 10 to 18 thousand years ago. Now, the land is answering the glacial changes, which are significant enough for us to be able to measure them.” The land rise is happening at the most rapid rise in the Sprengisandur area. That area has risen about three centimetres per year for the last decades, and the land rise rate is only increasing.

Land sinking in South-West Iceland
The situation is different in South-West Iceland, as the land is sinking there. That part of the country is far from glaciers, but there’s also been a lack of volcanic activity in the area for a long time. “The Reykjanes peninsula sits on the plate boundary where the country is sliding apart. There’s been no volcanic activity there for around 800 years which means that the plate boundary sinks, as there’s a lack of material,” says Páll. This will change in a relatively short time, at least when it comes to geology, as volcanic activity is expected to resume in the next decades or hundreds of years. Areas which are vulnerable to land sinking, such as Seltjarnarnes and Álftanes, have had to react by placing expensive sea walls comprised of large rocks, on the coastline.

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Seltjarnarnes and Álftanes are threatened by rising sea levels. The coastline of both areas has been reinforce with sea walls made of large rocks

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The south-west peninsula of Iceland is sinking due to its placement near the Reykjanes tectonic plate ridge. A lack of volcanic activity in the area has led to a dearth of material.

Greenland glacier affects local conditions
The size of the Greenland glacier affects Iceland in two ways. The glacier has shrunk significantly due to global warming. “The mass of the Greenland glacier draws sea toward itself and forms a sort of sphere. The grand mass of the glacier is disappearing, and the attraction lessens which affects sea levels,” according to Páll. Greenland is rising due to the melting of the glaciers, much like Iceland, and the rise of Greeland also affects Iceland. The material in the mantle streams towards Greenland which leads to the sinking of the land under the South-West part of Iceland. The effect of the glacial changes in Iceland has a more profound effect, though.

Projections indicate that all of the Icelandic glaciers will have disappeared in 200 years due to global warming. “As things stand now, the world temperature appears to be rising. Then, the melting will take place in a shorter time span.”