Katla volcano

About Katla volcano

Katla is one of Iceland's largest and most active volcanoes, hidden beneath the Mýrdalsjökull ice cap on the South Coast, just north of Vík and east of Eyjafjallajökull. Its central volcano holds a caldera about 9 by 14 km across, covered by ice up to 700 metres thick, so the volcano itself cannot be seen: what visitors see is the glacier on top of it and the landscapes its eruptions have shaped.

Katla has erupted at least 21 times in the last 1,100 years, on average about every 50 years. The last eruption to break through the ice was in 1918, and the current pause is the longest on record. When it erupts, melting ice sends huge glacial floods, called jökulhlaups, across the plains below; the black Mýrdalssandur sands east of Vík were built largely by such floods. The Eldgjá fissure eruption around the year 939, part of the Katla system, was one of the largest lava eruptions in Iceland's history.

The Icelandic Meteorological Office monitors Katla closely with seismometers, GPS stations and river sensors. Small earthquakes are frequent, and in July 2024 a glacial flood from the caldera damaged parts of Route 1 near the Skálm river and briefly raised the aviation colour code to yellow before it returned to green. There is currently no sign of an imminent eruption, but check the Met Office and SafeTravel for warnings before travelling in the area.

The most popular way to get close is a guided super-jeep trip from Vík to the Katla ice cave in Kötlujökull, an outlet glacier on the southern edge of Mýrdalsjökull, where the ice is streaked black with volcanic ash. These tours run all year, depending on conditions, and must be done with a guide. Katla is also visible on helicopter flights, and the drive along Route 1 past Mýrdalssandur shows the scale of its flood plains. Nearby are Sólheimajökull, Skógafoss and Eyjafjallajökull.