Magma accumulation beneath Svartsengi is nearing the critical threshold, with over 90% of the volume recorded before the last eruption on November 20, 2024, increasing the likelihood of a dike intrusion and possible eruption. Seismic activity remains steady, and land uplift continues.
Magma continues accumulating beneath Svartsengi at a rate nearing the levels observed before the previous eruption. Deformation measurements confirm ongoing ground uplift, with geophysical models estimating that the subsurface magma volume is approaching the threshold associated with past magma intrusions.
An M3.2 earthquake was recorded during the ongoing seismic activity near Grjótárvatn, Iceland, on January 16, 2025. It was the strongest event since August 2024. Nearly 100 earthquakes above M1 were recorded in January alone, matching the highest monthly count previously recorded in December 2024.
A powerful earthquake swarm started in the NW part of Bárðarbunga caldera, Iceland at 06:08 UTC on January 14, 2025. Initial data indicate that dozens of quakes occurred in rapid succession, hinting at possible volcanic or tectonic unrest deep beneath the ice. The current activity may be similar to the beginning of the swarm that occurred before the 2014 Holuhraun eruption.
Seismic readings indicated the onset of a glacial outburst flood from Grímsvötn volcano on January 13, 2025. Grímsvatn floods have occurred almost annually since November 2021. There are examples of volcanic eruptions occurring due to pressure relief in Grímsvötn after water gushes from there. However, glacial outburst floods have occurred much more frequently without volcanic eruptions.
Seismic activity near Grjótárvatn has increased with a tremor episode on January 2, 2025, indicating a potential deep magmatic intrusion. The IMO has reported earthquakes at depths of 15 to 20 km (9.3 to 12.4 miles) which suggests subsurface magma movement without surface deformation.
A strong earthquake swarm was registered on Iceland’s Reykjanes Ridge between December 28 and 30, 2024. The activity was concentrated in a tectonically active area, with the strongest reaching M3.6.
The Icelandic Met Office (IMO) detected an earthquake swarm in Hofsjökull volcano on December 13, 2024, with the strongest quake recorded as M3.3 at a depth of 8.8 km (5.5 miles). The last eruption of the Hofsjökull volcano occurred approximately 12 000 years ago.
A civil defense project to further raise earthen dams around the Svartsengi Power Plant was initiated on December 9, 2024. The effort aims to safeguard the infrastructure against future lava flows.
The eruption that started on November 20, 2024, at the Sundhnúks crater row near Grindavik, Reykjanes Penisula, Iceland is now the second largest in the volume of the eruptions that have occurred in the Sundhnúks crater row since December 2023.
