Eruptive activity at Sundhnúk crater row continues at decreased intensity, Iceland

While the eruption at the Sundhnúksgígar crater row, southeast of Litla-Skógfell, Iceland continues on July 18, 2025, the eruptive activity has declined in the last 24 hours. The main activity is now in the center of the fissure and little to no seismic activity has been recorded in the magma chamber. 

When the eruption began on July 16, the magma from the eruption reached groundwater, producing spectacular emissions of vapor and ash as seen in the video above.

As of 11:30 UTC on July 18, the eruption at the Sundhnúk crater series continues, but its activity has decreased over the past 24 hours.

The main activity is now concentrated at the center of the fissure, and there’s little to no seismic activity coming from the magma chamber. The surface activity around the eruption site has also become less intense and more stable.

Gas emissions from the eruption have now spread across much of Iceland and are also clearly visible over the sea to the north and west of the country. Volcanic haze has affected large parts of the country, particularly in the northern and western regions.

Light winds and showers are forecast across much of the country over the next few days. Such weather conditions are conducive to continued localized volcanic haze in certain areas.

The fissure eruption at the Sundhnúksgígar crater row began at around 03:54 UTC on July 16. The eruptive fissure was approximately 700–1 000 m (2 300–3 280 feet) propagated northward, with lava flowing southeast.

The eruption prompted evacuations in of the Blue Lagoon Resort and the Grindavík town (population 4 000).

The Sundhnúksgígar crater row has experienced 8 eruptive episodes since late 2023. This is also the 12^th eruption in Reykjanes Peninsula since volcanic activity in the area increased in 2021, starting a series of eruptions expected to last decades or even centuries. These events typically involve lateral fissure eruptions, with lava output shaped by the underlying dike system and local topography.

Past eruptions have occasionally impacted infrastructure, prompting the construction of protective barriers and the preemptive evacuation of nearby sites, including Svartsengi and the Blue Lagoon.

The eruption’s duration remains uncertain and will depend on the magma supply rate and dike pressure dynamics. Previous events in this system have lasted from hours to several weeks.

Rishav Kothari

I am an Assistant Editor and Severe Weather & Science Journalist at The Watchers, specializing in real-time severe weather coverage, geophysical event reporting, and research-driven scientific analysis. You can reach me at rishav(at)watchers(.)news.

• Rishav Kothari

  Tropical Storm Amanda forms as the first named storm of the 2026 eastern Pacific hurricane season
• Rishav Kothari

  Severe Tropical Storm Jangmi leaves 23 injured, 60 000 without power after landfall in Wakayama, Japan
• Rishav Kothari

  Tornadoes touch down near Bridgewater, Wall Lake, and Centerville, South Dakota
• Rishav Kothari

  Deep M6.2 earthquake hits west of Calabria, Italy