Glacial Outburst Flood Has Begun in Grímsvötn

Vatnajökull Grímsfjall Grímsvötn Bárðarbunga Kverkfjöll Jöklar Jökull Vísindi

A glacial outburst flood has begun in Grímsvötn beneath Vatnajökull glacier, experts have confirmed. An M4.3 earthquake at Grímsfjall this morning alerted experts to increased activity at the site. While such floods are known to increase the likelihood of volcanic eruptions, there are no indications an eruption is imminent at the site.

In an interview with RÚV, Professor of Geophysics Magnús Tumi Guðmundsson confirmed the glacial outburst flood began several days ago in the highland region. Elevated water levels have already reached inhabited areas further south, but they are not significant. “There is more water in Gígjukvísl river,” Magnús Tumi stated. “However, this is not a big event, it just looks like the summer water levels. It’s not a lot and it’s equivalent to a small or medium-sized glacial outburst flood in Skaftá river.”

Strongest earthquake in a long time

The M4.3 earthquake that occurred just before 7:00 AM this morning is “noteworthy,” according to Magnús Tumi. He says it’s “the biggest one we know of there for a very long time.” The earthquake hasn’t been followed by others of a similar magnitude, however, and appears to be a one-off event.

What is a glacial outburst flood?

Grímsvötn is an active volcano located beneath Vatnajökull, Iceland’s largest glacier. It has the highest eruption frequency of all the volcanoes in Iceland, but is located far from any inhabited areas. The geothermal and volcanic activity at Grímsvötn causes regular glacial outburst floods, known as jökulhlaup. Such outbursts are triggered by geothermal heating beneath the glacier which causes ice to melt, and eventually be abruptly released from beneath the glacier, into the surrounding water systems.

Magnús Tumi says Grímsvötn is now in a period of increased activity, which typically lasts between 60-80 years. It last erupted in 2011.

No Red Weather Warnings in Iceland in 2023

weather warning map

No red weather alerts were issued in Iceland last year. The year’s weather was relatively calm, at least when considering the number of weather warnings issued. The total number of warnings issued by the Icelandic Met Office was 311, which is slightly below average. Of those warnings, 280 were yellow weather warnings and 31 were orange weather warnings.

Weather fluctuates between years

The numbers are significantly lower than in 2022, when 456 weather warnings were issued: 372 yellow, 74 orange, and ten red. When data from the past six years is compared, it is clear that the number of weather warnings fluctuates considerably between years. In 2020, just 235 weather warnings were issued, while in 2020, the total number of weather warnings was 531.

Last year’s weather warnings were fairly evenly distributed across the country’s regions, with around 25-35 warnings issued for each region. The capital area and East Iceland received just 15 and 18 weather warnings respectively, however.

Most warnings due to wind

Most of the weather warnings issued in 2023 were due to strong winds, although warnings were also issued due to rain, snow, and rapid thawing (known to cause flooding). Yellow weather warnings indicate a high probability of poor weather with limited societal impact, while red weather warnings indicate that the weather conditions will have a significant impact on society.

Home for the Holidays: Grindavík Welcomes Back Residents

Grindavík - Þorbjörn

Beginning tomorrow, December 23, Grindavík residents will be allowed to return and stay overnight in town. Following the subsidence of the volcanic eruption near Sýlingafell, the authorities have decided to downgrade the alert status in Grindavík from an Emergency Phase to a Danger Phase.

Christmas after all

Beginning tomorrow, December 23 (The Mass of St. Thorlac, i.e. Þorláksmessa), the residents of Grindavík are permitted to enter and even stay overnight in the town, Vísir reports. Christmas in Grindavík will, therefore, be celebrated after all, at least by those Grindavík residents who wish to do so. This was noted in an announcement from the Police Commissioner of Suðurnes. The situation will be reassessed on December 27. 

The statement also notes that starting from December 23, roadblocks will be established on Grindavíkurvegur, Nesvegur, and Suðurstrandarvegur. These measures allow Grindavík residents, business owners, and their employees to bypass the roadblocks at any time and permit overnight stays within the town. However, access beyond these roadblocks is currently restricted to unrelated individuals, while major media outlets are granted passage.

Alert status lowered to Danger

As noted by Vísir, experts from the Icelandic MET Office at 9.30 AM today to review the latest data. At 1:00 PM, the MET Office held another meeting with the Police Commissioner in Suðurnes and the Commissioner of the Department of Civil Protection and Emergency Management.

Based on the latest risk assessment map from the Icelandic MET Office, Grindavík still faces a significant risk of natural disasters. Following indications that the volcanic eruption near Sundhnúkagígar, which started on December 18, has ceased, the National Commissioner of the Icelandic Police, in consultation with the Police Commissioner of Suðurnes, has opted to lower the alert status from an Emergency Phase to a Danger Phase.

Glacial Outburst Flood Has Begun in Skaftá River

A glacial outburst flood has begun in Skaftá river in South Iceland, the Icelandic Met Office reports. The water level and flow rate in the river began to increase last night and increased electrical conductivity was also measured. Rangers in Hólaskjól also reported smelling sulphur in the area. The National Police Commissioner and Department of Civil Protection have issued an uncertainty phase due to the event.

The last glacial outburst flood in Skaftá occurred two years ago, in September 2021. Floods in Skaftá are sourced from two ice cauldrons beneath Vatnajökull glacier which usually burst one at a time, but it is possible that this flood is sourced by both the western and eastern cauldrons, according to the Met Office. The 2021 glacial outburst flood was sourced by both cauldrons.

Risk of floods and gas poisoning

There are several hazards associated with such natural events. Firstly, flood conditions are expected in Skaftá river over the next two to three days and some flooding of roads near the river is possible. Secondly, hydrogen sulphide is released from the floodwater as it drains from the Vatnajökull ice cap. The gas is particularly potent at the ice margin, where it can reach poisonous levels of concentration. Travellers are advised to stay away from the edges of Skaftárjökull, Tungnaárjökull, and Síðujökull, where floodwater could burst through the surface. Lastly, travellers on Vatnajökull should stay away from the region, as crevasses will develop rapidly around the ice cauldron.

The cauldrons that source the glacial outburst floods in Skaftá drain every two years on average, producing floods of up to 1,500 cubic metres per second.

No Changes in Geothermal Activity at Askja Volcano

Michelle Parks / Veðurstofan. Dr Melissa Anne Pfeffer taking gas measurements at Askja.

There are no changes to geothermal activity at Askja volcano, according to preliminary results from a recent research trip conducted by the Icelandic Met Office. The land at Askja has risen 70 cm over the past two years, indicating that some 20 million cubic metres of magma are collecting under the volcano’s surface. An uncertainty phase has been in effect at the site of the remote highland volcano since September 2021.

Eruption on the way?

Volcanologists in Iceland have been predicting that Askja is preparing for an eruption in the near future. While uplift (land rise) has been occurring at the site for around two years, this summer local rangers reported that the temperature of the site’s geothermal lake Víti had risen. A plume of steam was also reportedly sighted at Askja this summer.

Plume of steam was likely dust

A group of scientists from the Icelandic Met Association led by Dr. Melissa Anne Pfeffer and Dr. Michelle Parks made a trip to Askja recently to collect data at the site, including gas and water samples. The preliminary results show no changes in gas or water from previous years, though the samples are being analysed futher at this time. There are no visible changes in the landscape and measurements of temperature and acidity do not indicate chanes in the geothermal activity around Askja and Víti geothermal lake. The report of a plume of steam seen at the site on August 12 has been interpreted as dust from a rock fall on the steep slopes of the caldera.

Askja is a volcano situated in Iceland’s central highland region. Its last eruption occurred in 1961 and gave clear warning in the form of strong earthquakes and a significant rise in geothermal temperatures. No such signs have yet occurred at the site. Tourism operators have nevertheless called for improved telecommunications at the site in case of an eruption.

April Warmer and Sunnier than Average in Iceland

Árbæjarsafn Reykjavík on April 20, 2023, the First Day of Summer

Last month was the seventh-warmest April on record in Reykjavík, according to the latest figures from the Icelandic Met Office. April weather was calm and warm across Iceland, though it cooled down in the last week of the month.

The average temperature in Reykjavík in April was 5.3°C [41.5°F], which is 1.6°C above the 1991-2020 average and 1.2°C above the average for the last ten years. The average temperature in Akureyri, North Iceland, was also 1.6°C above the 1991-2020 average, at 4.2°C [39.6°F]. That is one degree higher than the average for the last decade. In Stykkishólmur, West Iceland, the average temperature was 4.0°C [39.2°F] and in Höfn, Southeast Iceland, the average temperature was 4.4°C [39.9°F]. The April temperatures recorded at 12 weather stations across the country all averaged higher than the April average of the past decade.

Surprise spring snow in Reykjavík

Despite pleasantly warm temperatures, Reykjavík received 87 millimetres of precipitation in April: 50% more than the 1991-2020 average. Akureyri received only about 85% of its average precipitation compared to the same period, or 21.7 mm. Reykjavík residents were surprised by heavy snowfall on April 27, which measured 11 cm [4.3 in] – such heavy snowfall is indeed rarely seen in the region in the second half of April. In Akureyri, however, no such “white” days were recorded last month, a drop from the monthly average of five. Both Reykjavík and Akureyri had more sunshine last month than the monthly average.

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The highest average temperature for last month was 6.3°C [43.3°F], recorded on Surtsey island in the Westman Islands archipelago off South Iceland. Visits to the island are forbidden for all but the members of an annual research expedition, so it can’t be said that these balmy temperatures were enjoyed by any of Iceland’s human residents – though the island’s avian inhabitants hopefully profited.

Surprise “Spring Snow” in Reykjavík

spring snow downtown Reykjavík

Capital area residents in Iceland opened their eyes this morning to a blanket of white outside their window. Snow began falling yesterday and measured 10 cm [3.9 in] deep this morning at the Icelandic Met Office. While residents of Reykjavík and the surrounding area are not unused to seeing some falling flakes at this time of year, Meteorologist Teitur Arason of the Icelandic Met Office says this much snow in late April is indeed a rare occurrence.

“In the last 75 years, there have only been 4 instances of this much snow falling in the Reykjavík area in the second half of April,” Teitur told Iceland Review. A high-pressure front coming in from the south that brought spring-like weather to Iceland in recent weeks shifted above Greenland last weekend, he explained. It was replaced by a small low-pressure system, bringing the snowfall that is uncharacteristic for this time of year.

spring snow downtown Reykjavík
Golli. Spring snow in Reykjavík on April 27, 2023.

While Reykjavík skies remain clear this morning, South Iceland will receive its fair share of snowfall today, and travellers in the area are encouraged to check conditions before heading out. Teitur says the capital area may see more snowfall tonight. Weather in the area is then expected to remain cold, even dipping below the freezing mark in the coming days but should warm up from Tuesday or Wednesday next week.

Orange Weather Alert Tomorrow Morning Across Iceland

orange weather alert Icelandic met office storm

Travellers across Iceland are asked to stay put tomorrow morning, as gale-force winds and blizzard conditions will hit nearly all regions of the country. The Icelandic Met Office has issued an orange weather alert between 6:00 AM and 1:00 PM tomorrow, with conditions expected to improve in the afternoon.

The storm will arrive from the southwest, hitting the Reykjavík capital area, south, and west of the country early tomorrow morning. It will move eastward across the country, with orange alerts issued for all regions except the Ísafjarðardjúp area, for which a yellow alert has been issued.

The storm will bring winds of 20-28 metres per second with violent wind gusts of over 40 metres per second expected near mountains. The winds make travel extremely dangerous and carry a risk of property damage: residents are encouraged to secure outdoor belongings before the storm hits. Heavy precipitation in the form of sleet or snow is expected across the country, particularly in South, North, and East Iceland and will create blizzard conditions and poor visibility.

Travellers can monitor the forecast on the Icelandic Met Office website and road closures and conditions at

Earthquakes Near Grímsey: Uncertainty Phase Declared

The National Commissioner of Police and the Chief of Police in Northeast Iceland declared an Uncertainty Phase on Friday due to ongoing seismic activity around the island of Grímsey. RÚV reports that an earthquake measuring 4.9 was detected around the island at 4 AM on Thursday morning; since then, there have been roughly 2,600 earthquakes. At 1:20 PM on Friday, there was another large quake of 4.1 and several over a magnitude of 3.0 occurred after that.

Per the Department of Civil Protection and Emergency Management, an Uncertainty Phase is “is characterized by an event which has already started and could lead to a threat to people, properties, communities or the environment. At this stage the collaboration and coordination between the Civil Protection Authorities and stakeholders begins. Monitoring, assessment, research and evaluation of the situation is increased. The event is defined and a hazard assessment is conducted regularly.”

People who live in known earthquake areas in Northeast Iceland are advised to take appropriate measures to prepare for ongoing seismic activity. These include securing household items, such as flatscreen TVs and breakable décor, taking down paintings or photos that can fall on people while sleeping, moving beds away from windows, and familiarizing oneself with the Duck – Cover – Hold procedure. More information on natural disaster preparedness can be found on the Department of Civil Protection and Emergency Management’s website, in English, here.

Seismic activity is common in Northeast Iceland, and according to a natural disaster expert at the Met Office, there is currently no indication of a pending volcanic eruption.

Historically Cold Summer Confirmed in Recent Report from Met Office

icelandic weather summer temperatures

According to a recent report from the Meteorological Office of Iceland, this year’s summer has broken records for low temperatures.

In total, there were 27 days when the temperature exceeded 20°C (68°F) in all of Iceland. Compared to last summer, there were 57 such days of higher temperatures.

The highest recorded temperature this summer was in Mánárbakki in Northeast Iceland, an area that often has sunny and warm weather in the summer.

Reykjavík only managed to register 18°C (64°F) this summer, a 20-year year record that was only lower in 2001.

However, summer is still not entirely over. Relatively calm and warm weather is expected this weekend. Unlikely to break records, it should still be good weather for the final days of hiking, fishing, berry picking, and other outdoor activities this year.