New unrest pulses beneath Mýrdalsjökull — the glacier that caps the feared Katla volcano in southern Iceland — have been detected, prompting heightened monitoring from Veðurstofa Íslands (the Icelandic Meteorological Office). The nearby Vík í Mýrdal area and its small airport have both drawn fresh attention as scientists watch the data closely. No eruption is imminent, but the activity is significant enough to warrant public awareness.
Key takeaways
- Unrest tremors have been detected beneath Mýrdalsjökull, home to the powerful Katla volcano.
- Scientists are monitoring closely, but no eruption warning has been issued at the time of writing.
- Katla has not had a confirmed full eruption since 1918 — making any new activity internationally newsworthy.
- An eruption under Mýrdalsjökull could trigger a glacial outburst flood (jökulhlaup) and disrupt European airspace.
- Travellers should monitor Veðurstofa Íslands and the Icelandic Civil Protection for real-time updates.
What is causing the unrest tremors under Mýrdalsjökull right now?
Seismic unrest beneath Mýrdalsjökull is being driven by a combination of earthquake swarm activity and, according to reports, tremor pulses consistent with fluid or magma movement at depth. Katla sits in a highly active volcanic zone along Iceland’s Eastern Volcanic Zone, where the North American and Eurasian tectonic plates pull apart. Pressure builds episodically in Katla’s magma chamber, occasionally releasing energy in the form of tremors and small earthquakes — even without a full eruption following.
Morgunblaðið reported the latest unrest pulses, and Veðurstofa Íslands has been updating its monitoring data on the official Katla monitoring page. Scientists distinguish between two types of signals here: volcano-tectonic earthquakes caused by rock fracturing, and tremor — a more continuous, rhythmic signal often linked to moving fluids. The current episode appears to include both, which is why it is drawing attention beyond routine background noise.
Mýrdalsjökull is Iceland’s fourth-largest glacier, covering roughly 600 square kilometres and reaching up to 1,493 metres at its highest point, Hábunga. The ice cap sits directly over Katla’s caldera, a roughly 10-kilometre-wide depression that contains the volcano’s main vent system. Any magmatic activity beneath that ice has consequences that reach far beyond Iceland’s south coast.
Is Katla volcano about to erupt?
No eruption warning has been issued. Veðurstofa Íslands and the University of Iceland’s Institute of Earth Sciences — the two primary scientific authorities on Katla — have not elevated the aviation colour code to orange or red as of the time of publication. However, scientists are careful not to dismiss the signals. Katla is, by geological standards, overdue for a major eruption. Its last confirmed full eruption was in 1918, and historically it has erupted roughly every 40 to 80 years. That interval has now passed.
Tremor episodes beneath Mýrdalsjökull are not rare. Small unrest pulses have occurred multiple times in recent decades — notably in 1999 and 2011 — triggering jökulhlaup (glacial outburst floods) on the Mýrdalssandur plain south of the glacier, but not a full volcanic eruption. Each episode is studied closely because scientists cannot yet reliably predict whether unrest will escalate or subside. So while Katla is not erupting right now, the situation warrants attention precisely because the volcano’s history demands it.
Could an eruption under Mýrdalsjökull disrupt flights?
Yes — and potentially on a large scale. Katla is considered one of the most dangerous volcanoes in Iceland specifically because of the combination of a large magma reservoir and the thick Mýrdalsjökull ice cap sitting above it. An eruption melting that ice would almost certainly generate a catastrophic jökulhlaup, flooding the Mýrdalssandur and the Ring Road (Route 1) within minutes. Simultaneously, a major subglacial eruption would blast volcanic ash high into the atmosphere.
That ash is the main concern for European aviation. Katla is believed capable of producing an eruption several times larger than the 2010 Eyjafjallajökull event, which famously shut down European airspace for six days and disrupted more than 100,000 flights. The London-based Volcanic Ash Advisory Centre (VAAC) would issue advisories, and affected airlines would be required to suspend operations across potentially wide corridors of North Atlantic and European airspace.
Locally, the small airport serving the town of Vík í Mýrdal — the closest community to Mýrdalsjökull, sitting barely 30 kilometres from the glacier’s southern edge — has reportedly just reopened after a separate period of closure. Its status would change rapidly in any eruption scenario. Travellers on the south coast of Iceland, particularly those driving Route 1 between Vík and the Mýrdalssandur plain, should be aware of evacuation routes and assembly points, which Almannavarnir (the Department of Civil Protection and Emergency Management) has published and rehearsed with local communities.
How does this compare to previous Katla activity?
Katla has produced more than 20 confirmed eruptions since Iceland was settled in the ninth century. The most recent full eruption, in October 1918, melted massive amounts of glacier ice and sent a jökulhlaup toward the coast estimated to have briefly exceeded the combined flow of the Amazon and Congo rivers. That eruption extended Iceland’s south coast by several kilometres as the flood deposited sediment on the Mýrdalssandur plain.
Since 1918, Katla has shown repeated unrest without a full eruption breaking through the ice. The 1999 episode caused a localised jökulhlaup that damaged bridges on the Mýrdalssandur. In July 2011, a more significant swarm occurred, again producing a small glacial flood and generating international headlines — but no eruption followed. Scientists from the Nordic Volcanological Center have noted that each unrest episode adds data, but predicting whether any given episode will escalate remains beyond current science.
The current tremors sit within that historical pattern. They are consistent with Katla’s known behaviour, but the volcano’s long quiet since 1918 means any escalation would be treated with the utmost seriousness by Icelandic authorities.
What is the current alert level for Mýrdalsjökull?
At the time of publication, the aviation colour code for Katla/Mýrdalsjökull remains at yellow — meaning the volcano is exhibiting signs of elevated unrest above background levels, but no eruption is in progress or considered imminent. Veðurstofa Íslands uses a four-level colour code system for aviation: green (normal), yellow (unrest), orange (heightened unrest or eruption likely), and red (eruption in progress with significant ash emission).
Yellow is not a cause for immediate alarm, but it is a formal signal that monitoring has intensified and that the situation could change. Readers — particularly travellers in the south of Iceland — should bookmark the Veðurstofa Íslands volcano status page and check it before driving the Ring Road south of Selfoss or visiting areas near Vík í Mýrdal or the Þórsmörk highland valley, which lies directly north of the glacier.
What travellers on Iceland’s south coast should do now
Practical steps matter in a fast-moving situation. If you are currently in southern Iceland or planning to be, here is what to keep in mind:
- Check Veðurstofa Íslands daily: The official status page at en.vedur.is updates in real time with seismic data, tremor charts, and aviation colour codes.
- Follow Almannavarnir: Iceland’s Civil Protection authority publishes evacuation zone maps and emergency instructions at almannavarnir.is.
- Know the evacuation routes: In Vík í Mýrdal, residents and visitors are directed to climb the hill toward the church (Víkurkirkja) — a well-known local landmark — if a jökulhlaup warning is issued. The hill is the official muster point for flood emergencies.
- Check your flight status directly: If you are flying through Keflavíkurflugvöllur (Keflavík Airport) or any other Icelandic airport, monitor your airline and Isavia (Iceland’s airport and air navigation authority) for any disruption alerts.
- Travel insurance: Confirm your policy covers volcanic disruption — many standard policies exclude natural disasters unless specifically purchased as an add-on.
Frequently asked questions
Is it safe to visit Vík í Mýrdal and the south coast of Iceland right now?
As of the current alert level (yellow), there is no official restriction on travel to Iceland’s south coast, including Vík í Mýrdal. The town sits close to Mýrdalsjökull and would be among the first areas affected by a jökulhlaup if an eruption occurs. Travellers should stay informed through Veðurstofa Íslands and Almannavarnir, and familiarise themselves with local evacuation procedures — particularly the instruction to move to high ground near Víkurkirkja — before arriving.
How big could a Katla eruption be compared to Eyjafjallajökull in 2010?
Scientists estimate that a full Katla eruption could be significantly larger than the 2010 Eyjafjallajökull eruption, which paralysed European airspace for nearly a week. Katla’s magma chamber is considerably bigger, and the volume of ice above it on Mýrdalsjökull means a subglacial eruption would produce more explosive steam-driven activity and potentially more ash. A major Katla eruption is widely regarded as one of the highest-impact natural hazard scenarios for European aviation.
When did Katla last erupt?
Katla’s last confirmed full eruption was in October 1918. It lasted roughly four weeks and produced a massive glacial outburst flood that temporarily extended Iceland’s southern coastline. Since then, Katla has shown repeated periods of unrest — including in 1955, 1999, and 2011 — but none of those episodes escalated into a full eruption breaking through the Mýrdalsjökull ice cap.
What is a jökulhlaup and why does it matter?
A jökulhlaup (pronounced roughly YOH-kul-hloip) is a glacial outburst flood caused when volcanic heat rapidly melts large quantities of glacier ice. Beneath Mýrdalsjökull, a Katla eruption could release billions of litres of meltwater within minutes, sending a wall of water and ice across the Mýrdalssandur plain toward the coast. The 1918 jökulhlaup is estimated to have briefly produced a discharge greater than the Amazon River. It would destroy roads, bridges, and any structures in its path.
Where can I get real-time updates on Katla and Mýrdalsjökull unrest?
The most reliable sources are Veðurstofa Íslands (the Icelandic Meteorological Office) at en.vedur.is, which publishes live seismic data and aviation colour codes, and Almannavarnir (Civil Protection) at almannavarnir.is for safety and evacuation guidance. For flight-specific disruption, Isavia’s website and individual airline customer service channels are the best first contacts. Iceland’s public broadcaster, RÚV, also publishes English-language updates during significant volcanic events at ruv.is/english.
