This live blog has now ended as a result of the reduced risk of an eruption. It will be restarted if activity signalling imminent threat resumes.
Iceland is bracing for an imminent volcanic eruption on the Reykjanes Peninsula, in the southwest corner of the island. Grindavík, a small fishing town with a population of around 2,800 people, has been evacuated after a sinkhole measuring 3.2 feet (1 meter) deep appeared in the town.
Seismic activity began increasing in the area around the Fagradalsfjall volcano on Oct. 25, when more than 1,000 earthquakes north of Grindavík occurred in the space of just hours. Two strong earthquakes, measuring magnitudes 3.9 and 4.5, hit at a depth of around 3 miles (5 kilometers). Over the following two weeks, seismic activity continued, with hundreds of earthquakes and uplift recorded each day, indicating that magma is accumulating beneath the ground.
On Nov. 11, Icelandic Met Office (IMO) data showed there was a "magma tunnel" about 9.3 miles (15 km) from Sundhnúk in the north down to Grindavík and into the sea. Experts say an eruption could take place anywhere along this tunnel — also known as a dike.
Timeline of events:
- Nov. 20 — IMO releases new map showing extended "danger zone" around the magma dike. Hagafell currently considered the most likely spot for a fissure to appear.
- Nov. 15 — IMO reports seismic activity has remained consistent since Nov. 11, with monitoring centered around Grindavík.
- Nov. 14 — Icelandic authorities create makeshift defenses to protect the Svartsengi geothermal power plant from lava flows.
- Nov. 10 — Grindavík evacuated due to the increase in seismic activity gravitating towards the fishing village. Icelandic authorities declare a state of emergency.
- Nov. 9 — The largest recorded earthquake since the swarm began reaches a magnitude of M4.8. Blue Lagoon geothermal resort, one of the country's most famous tourist attractions, is temporarily closed.
- Nov. 4 — Seismic activity decreases considerably, but Icelandic Meteorological Office continues to monitor the situation.
- Oct. 25 — Seismic activity in the Reykjanes Peninsula increases with more than 1,000 earthquakes registered in the area, the largest with a magnitude of M4.5.
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'Time's finally up': Impending Iceland eruption is part of centuries-long volcanic pulse
Iceland's potentially imminent eruption in the Reykjanes Peninsula is part of a 1,000-year cycle of volcanic activity that will likely cause eruptions for centuries, scientists say.
"Time's finally up," Edward W. Marshall, a researcher at the University of Iceland's Nordic Volcanological Center, told Live Science in an email. "We can get ready for another few hundred years of eruptions on the Reykjanes."
Seismic activity began increasing in the south of the peninsula in October, with hundreds of earthquakes recorded there each day. On Nov. 10, authorities evacuated the town of Grindavík, with experts warning an volcanic eruption could take place in just days.
800 earthquakes recorded since midnight
Around 800 earthquakes have been recorded since midnight, Nov. 15. Most hit at the center of the magma dike, according to a translated statement from the IMO.
The continuing ground deformation is likely being caused by magma flowing into the dike, experts say
"Part of the magma dike seems to be solidifying, especially at the edges, but not at the magma inflow area, which is believed to be near Sundhnúk," according to the statement. "The probability of an eruption is still considered high. In the event of an eruption, the most likely location is at the magma dike."
Officials scramble to protect vital power plant from imminent lava flows
On Tuesday (Nov. 14), Icelandic authorities started creating makeshift defenses to protect the Svartsengi geothermal power plant from lava flows that may emerge if the magma dike erupts over the next few days, Reuters news agency reported.
The Svartsengi plant uses heat from the underground magma in the region to heat water and turn turbines. It is located around 4 miles (6 km) from Grindavík, which has been evacuated over fears of the imminent eruption, and supplies power across the country, as well as hot water to the local area.
Workers have begun digging out channels to divert the lava away from the plant if molten rock heads in that direction.
Iceland’s volcanic activity is generally tame compared with explosive eruptions along the Pacific’s Ring of Fire. Jaime Toro, Professor of Geology at West Virginia University, explains what the main causes for volcanic activity in the region are, and what effect this has on eruptions.
"The answer has two parts — one has to do with what geologists unimaginatively call a hotspot, and the other involves giant tectonic plates that are pulling apart right beneath the island."
Experts have warned that an underground magma tunnel between a pair of Icelandic towns could erupt at any moment. But what will this eruption look like? And how far-reaching will its effects be?
Could scientists artificially trigger the eruption safely?
There have been no new reports from the IMO since yesterday (Nov. 15) of any further earthquakes or the likelihood of an eruption, and as such the situation remains unchanged.
But would it be possible to prematurely trigger the upcoming eruption by drilling into the magma dike beneath the surface, potentially helping to control where the lava flows out of the ground? We asked an expert, who told us that it probably couldn't work.
"I am not sure that it is technically possible," Benjamin Andrews, a geologist at the Smithsonian Institute's National Museum of Natural History and director of the institute's Global Volcanism Program, told Live Science.
The magma in the dike is very viscous and would not be able to flow through a narrow opening, Andrews said. So "a very large hole would need to be bored for the magma to flow through." With magma reaching temperatures between 2,000 and 2,200 Fahrenheit (1,100 to 1,200 degrees Celsius), any drilling equipment would also likely be destroyed by the molten rock, he added.
Even if an eruption could be artificially triggered, this type of geoengineering solution is also "fraught from a legal and ethical standpoint," Andrews said.
Eruption still likely in next few days, experts say
An eruption is still likely to take place over the coming days, experts have said. Kristín Jónsdóttir, program director for earthquake monitoring at the Icelandic Meteorological Office, told Iceland's national broadcasting service RÚV that the probability of an eruption is not decreasing and seismic activity is being monitored closely.
She said the only experience they have is the 2021 eruption of Fagradalsfjall. In this event, tens of thousands of earthquakes were recorded in the weeks leading up to the eruption.
According to an updated statement from the IMO, 2,000 earthquakes have been recorded in the region in the last 24 hours. Ground deformation is ongoing, although its rate is slowing. If an eruption does take place, it is most likely to be north of Grindavík, near Hagafell.
"There is still a high probability of a volcanic eruption," representatives wrote.
Lava could reach the Blue Lagoon and Svartsengi power plant in days
If the magma dike beneath Iceland's Reykjanes Peninsula erupts, lava flows could quickly reach the Blue Lagoon resort and the Svartsengi geothermal power plant.
Magma is currently estimated to be 2,600 to 1,640 feet (800 to 500 m) below the surface and the rate of inflow to the dike appears to be constant, meaning the risk of eruption is still very high.
"If magma inflow continues at a constant rate for an extended period, I imagine the dike will grow and reach the surface in the coming days or weeks," Alberto Caracciolo, a researcher at the University of Iceland's Institute of Earth Sciences, told Live Science in an email.
"The extent of lava flows will vary depending on the specific location where the fissure opens, on the magma output rate and on the duration of the eruption," he said. "However, in most of the scenarios, lava could reach the power plant and the Blue Lagoon very quickly, in less than [a] few days. A similar fate is likely expected for Grindavík, especially if the fissure opens up in the southernmost part of Hagafell."
Land at Svartsengi power plant rising at a faster rate
Thorvaldur Thordarson, a volcanologist at the University of Iceland, has said the rate of uplift around the Svartsengi power plant, which feeds the nearby Blue Lagoon spa resort, is now faster than it was before Nov. 10, when a magma dike formed beneath the ground in the south of Reykjanes Peninsula.
"This goes hand in hand as the magma is creating space and lifting the surface of the earth up," he told the Iceland Monitor, according to a translation.
Thordason told Iceland's national broadcaster RUV that the land around Svartsengi initially fell around 15 inches (40 centimeters), but it is now almost back to its previous level. "When it reaches a similar level as it reached before November 10, you can expect something to happen," he said, according to a translation.
Freysteinn Sigmundsson, a geophysicist at the University of Iceland, said the most likely explanation for the uplift was magma flowing into the region. He told the Iceland Monitor that what happens next depends on how much the magma moves and how fast, adding that the sequence of events taking place is similar to what happened before the eruption of Fagradalsfjall in 2021 — except in this event the magma was much deeper.
"Then I think an eruption over the current magma tunnel is the most likely scenario."
According to RUV, 460 earthquakes have been recorded at the magma dike since midnight.
Danger zone from impending eruption has expanded
A new map showing the areas experts believe are at greatest risk from the impending volcanic eruption has been released by representatives with the IMO.
In a translated statement, they wrote that new satellite images showing Svartsengi and the magma dike mean the "danger zone has been expanded."
The zones at greatest risk include Hagafell, which is about halfway along the 9.3 mile (15 kilometer) magma dike, to the northwest of Grindavík. This region is considered to be the most likely place for an eruption to occur. Grindavík is placed in the red zone, which means there is a risk of a fissure opening at short notice and releasing lava, but the risk is smaller than in the purple zone.
Svartsengi in the north is at risk of experiencing earthquakes.
Weather to impact monitoring
Earthquake activity along the magma dike appears to have dropped slightly compared with recent days. However, this may be the result of strong winds impacting the sensitivity of seismic instruments, making it difficult to detect the smallest earthquakes according to the IMO.
"The effectiveness of this monitoring depends on the good sensitivity of seismic and real-time GPS measurements, but the sensitivity is highly dependent on weather conditions," IMO representatives wrote in a translated statement. Strong winds and rain are expected for the next two days, meaning real-time monitoring will be reduced.
Experts "will continue to monitor the area as well as possible and constantly reevaluate and interpret the data that is received."
What are the signs an eruption is just about to happen?
What will happen just before a fissure appears at the surface is currently unclear — although the presence of gases like sulfur dioxide and carbon dioxide would indicate magma is close to the surface. Increased seismic activity could also suggest heightened activity beneath the ground.
"Another sudden increase in magnitude and number of earthquakes would be a bad sign," Jaime Toro, professor of geology at the West Virginia University, told Live Science in an email. "Also, continuing ground deformation, increase of surface heat flow, gas emissions. In other words, the things that are happening."
Ármann Höskuldsson, a volcanologist with the University of Iceland's Nordic Volcanological Center, told Live Science in an email that low-frequency earthquakes would be a telltale sign, as it would suggest CO2 has started to escape the magma.
Earthquake activity is also associated with the movement of magma. However, before the eruptions at the nearby Fagradalsfjall volcano, seismic activity appeared to drop off before a fissure appeared. "There was a silent spot before magma reached the surface and erupted," Dave McGarvie, a volcanologist at Lancaster University in the U.K., who studies Iceland's volcanoes, told Live Science in an email.
Whether this would happen again is unknown, however.
McGarvie also said the presence of gases would likely be a precursor to an eruption. "If there was an extensive gas monitoring network then one sign would be a noticeable leak of magmatic sulfur dioxide from a specific area, as this would indicate magma rising to the surface and so this could be a site for a potential eruption," he said.
Live stream shows earthquake activity at center of danger zone
Live data from a seismic monitoring station near Hagafell — the spot experts think the volcanic eruption is most likely to take place — is showing current earthquake activity, which may indicate if magma is moving closer to the surface for an eruption to take place.
It is just a small sample of the tens of thousands of earthquakes that have occurred along a stretch of the Reykjanes Peninsula in recent weeks.
The feed, from the University of Cambridge Volcano Seismology Group, shows earthquakes being recorded at the Melhóll seismic station, which sits almost directly above the magma dike. Waves show the three axes of the seismograph: up/down, north/south and east/west motions.
While an eruption could take place anywhere along the dike, the most likely spot for an eruption appears to be around Hagafell, about 1.2 miles (2 km) north west of Grindavík, according to the IMO.
'It may take more time': Risk of eruption from Iceland volcano still high, with ground 'continuing to swell'
The risk of a volcanic eruption on Iceland's Reykjanes Peninsula is still very high, with ground deformation and earthquakes continuing along the magma dike — a near-vertical underground tunnel running from a magma chamber towards Earth's surface.
In an interview with mbl.is the same day, Benedikt Gunnar Ófeigsson, head of deformation measurements at the IMO, said the risk of eruption may slowly be decreasing. "If we look at the conditions in the magma tunnel, maybe the probability of eruption is slowly decreasing," he said. "But it is far too early to rule out that possibility."
Activity at the magma system would need to cease for the eruption risk to be lowered. And this is not the case.
"I don't think that the risk of an eruption is starting to fall," Bill McGuire, emeritus professor of Earth sciences at University College London in the U.K, told Live Science in an email. "In fact, GPS data show that the ground surface in the vicinity of the fracture is continuing to swell, which is likely caused by the continued emplacement of magma at shallow depths. In addition, hundreds of earth tremors are still happening every day."
Edward W. Marshall, a researcher at the University of Iceland's Nordic Volcanological Center, also said the risk of eruption is still high. "In Grindavík now, it is less than two weeks since dike injection," Marshall told Live Science in an email. "So it may take more time. The point is that the soonest possible scenario that an eruption would be designated 'unlikely' is in a week or two. But I think this episode will more likely go on longer."
Editor's note: A previous version of this post attributed McGuire's quotes to another scientist.
Icelandic authorities consider pumping water to control lava flow in case of eruption
Icelandic authorities have announced they are considering plans to pump water onto the lava in the event of a volcanic eruption on the country's southern Reykjanes Peninsula. This could help cool down the lava flow and control its forecasted spread towards the town of Grindavík, which was evacuated on Nov. 10. The method could also aid in protecting important infrastructure at risk from the imminent eruption, representatives told Agence France-Presse (AFP).
"An assessment technical team will arrive in Iceland tonight or tomorrow morning and they will assist us in assessing the possibilities," Víðir Reynisson, Iceland's head of civil protection and emergency management, told AFP on Wednesday (Nov. 22).
A high volume water pump was successfully used in 1973 to manage the spread of lava that erupted from a fissure on the island of Heimaey, off the southern coast of Iceland.
"This dike has been slowly expanding in the last week but has not reached the surface yet," Pȧll Einarsson, an emeritus professor of geophysics at the University of Iceland, told Live Science in an email. "It is by no means certain that it will result in an eruption, but the possibility must be considered, in particular because the dike lies underneath the town of Grindavík."
Fewer earthquakes have been recorded in recent days compared to when the risk of an eruption was first announced, according to the Icelandic Meteorological Office (IMO). But "weather and waves continue to affect the sensitivity of the system to detect the smallest earthquakes," IMO representatives wrote in the translated statement on Wednesday. "As deformation, seismic activity, and inflow into the magma tunnel continue to decrease, the likelihood of an eruption decreases over time."
The likelihood of a sudden eruption within the town limits of Grindavík is now considered low, they added. It is unclear when residents will be allowed to return.
Risk of eruption appears to be decreasing
The risk of a volcanic eruption on Iceland's Reykjanes Peninsula now appears to be decreasing, according to the IMO. In a translated statement, representatives wrote that seismic activity in the region has continued to decrease since Nov. 20. And while ground deformation is still being recorded around the Svartsengi power plant, it is slowing. The inflow of magma to the dike is also decreasing.
Since midnight on Friday (Nov. 24), around 300 earthquakes have been recorded near the magma dike, with most smaller than magnitude 1.
The fall in seismic activity, magma inflow and ground deformation means the likelihood of an eruption is decreasing, representatives wrote.
"If magma inflow into the dike stops or reduces significantly, the dike will slowly cool down, crystallize and solidify at depth," Alberto Caracciolo, a researcher at the University of Iceland's Institute of Earth Sciences, told Live Science in an email. "A dike with no inflow of fresh magma would solidify in a few days. It is possible that the dike is currently slowly solidifying, hence the [smaller] number of earthquakes."