More than 25 million m³ (883 million ft³) of magma has accumulated beneath Svartsengi, Iceland, since the last eruption in July 2025, the Icelandic Meteorological Office (IMO) reported on April 28, 2026. IMO said ground uplift continues at up to 2 cm (0.8 inches) per month, while magmatic dike propagation toward the Sundhnúkur crater row remains the most likely scenario and could lead to an eruption.
A strong seismic swarm began beneath Iceland’s Mýrdalsjökull glacier, part of the Katla volcanic system, around 10:30 UTC on October 20, 2025. Several earthquakes above magnitude 3 were recorded, the largest reaching M4.5 at 10:51 UTC. The Icelandic Meteorological Office reports no felt activity and no changes in river levels, conductivity, or deformation, indicating no immediate signs of eruption at the Katla volcano or glacial flooding.
Around 6 to 7 million m3 (212 to 247 million ft3) of magma have accumulated beneath Svartsengi, Iceland since the eruption on July 16, 2025. At the current rate of accumulation, the estimated threshold of 12 million m3 (424 million ft3) could be reached in the latter half of September, increasing the likelihood of a new eruption.
Volcanic haze and elevated levels of sulfur dioxide (SO2) from the Sundhnúk crater range eruption are affecting the western half of Iceland, especially the southwesternmost regions. The Icelandic Meteorological Office forecasts persistent volcanic haze in the south and west through Monday, due to slow and variable winds.
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.
A fissure eruption began at the Sundhnúksgígar crater row, southeast of Litla-Skógfell, Iceland, around 03:54 UTC on July 16, 2025. The eruptive fissure is approximately 700–1 000 m (2 300–3 280 feet) long and appears to be propagating northward, with lava flowing southeast and no immediate threat to infrastructure.
A glacial outburst flood has been developing in the Leirá syðri and Skálm rivers, southern Iceland, following rising water levels and electrical conductivity measured since July 7, 2025. Conditions continued to intensify as of 15:00 LT on July 9.
Low-level seismic tremor detected at Grímsfjall in recent days indicates possible internal water movement within the Grímsvötn subglacial lake system, southeast Iceland. The last eruption of this volcano took place in 2011 (VEI 4).
A Chinese research team tracked sulfur dioxide (SO2) from Iceland’s Sundhnukagigar volcano, which traveled over 2 000 km (1 243 miles) to the Svalbard Islands in the Arctic in 2023, causing significant smog. The findings, published in The Innovation Geoscience, documented the long-distance environmental impact of the eruption.
A new volcanic eruption has just begun north of the dam near Grindavík, Iceland, the Icelandic Met Office (IMO) reported at 09:45 UTC. A Coast Guard helicopter was sent to confirm the exact location and size of the eruption. This is the 11th eruption on the Reykjanes Peninsula since 2021 and the 9th on the Sundhnúk crater series.
