Volcano Alert: Sundhnúkur Crater Row Eruption Risk Rising
The Sundhnúkur Crater Row is on the brink of a potential eruption, with magma accumulation steadily increasing. This ongoing process, monitored by the Icelandic Meteorological Office (IMO), has been slow but consistent in recent weeks, raising concerns about an impending eruption.
Magma Accumulation: Slow and Steady
The magma accumulation beneath Svartsengi has been a gradual process, with the rate varying over time. Model calculations reveal that the inflow rate has decreased with each eruption, but it has remained steady over the past two weeks. This steady accumulation heightens the chances of a dike propagation or an eruption.
Timing Uncertainty: A Complex Puzzle
The timing of the next eruption is a challenging aspect to predict. When magma accumulation is slow, the uncertainty surrounding the eruption's timing increases. Current estimates suggest a window of several months, making it difficult to pinpoint the exact date.
Accumulated Magma: A Fifth Largest Volume
Since the last eruption, the amount of magma accumulated beneath Svartsengi has reached a significant milestone—it's the fifth largest volume to date. This accumulation has implications for the hazard assessment, which remains unchanged until January 6th, unless activity changes.
Seismic Activity: Low but Present
Seismic activity in the area is relatively low, with only a handful of small earthquakes detected in the past two weeks. These earthquakes are located between Stóra-Skógfell and Grindavík, indicating localized activity.
Weather's Impact: Sensitivity of Instruments
The weather forecast for the coming days includes strong winds and rain, which may affect instrument sensitivity. This is particularly true for fibre-optic cables, seismic, and real-time GPS instruments, which are crucial for monitoring volcanic activity. The IMO encourages the public to stay informed about weather warnings to ensure safety.
Historical Context: Past Eruptions and Accumulation
Looking back at previous eruptions, the rate of magma accumulation has been a key factor. The current accumulation rate is estimated at around 1 m³/s, and modeling shows that this rate has gradually decreased since 2023. The slower the accumulation, the more challenging it becomes to predict the timing of the next eruption.
Uncertainty in Timing: A Complex Puzzle
The timing of the next eruption is a complex issue. Experience from recent events suggests that even small changes in the accumulation rate can significantly impact the timing. This uncertainty is further emphasized by the varying thresholds for eruption triggers in different events.
Hazard Assessment and Monitoring
The hazard assessment, valid until early December, is based on modeling results and ongoing monitoring. The IMO closely monitors the situation, updating the assessment as needed. The public is advised to stay informed through official sources, as the situation may change rapidly.
Eruption Likelihood: A Rising Concern
The likelihood of a new magma intrusion and eruption is a growing concern. The accumulated magma volume beneath Svartsengi is approaching the threshold where the risk of an eruption increases. This situation warrants close attention and preparedness.
Seismic and Subsidence Activity
Seismic activity near Grindavík and the Sundhnúkur crater row is relatively low, with small earthquakes occasionally recorded. Meanwhile, subsidence continues near Krýsuvík, although at a slower rate in recent weeks.
Hazard Map and Monitoring
The hazard map, valid until late November, has been updated based on recent developments. The IMO maintains continuous monitoring, including real-time surveillance of seismic, deformation, and gas data, and provides regular updates to the public and relevant stakeholders.
Ongoing Monitoring and Preparedness
The IMO's 24-hour monitoring system ensures constant vigilance over Iceland's natural hazards. This includes the issuance of warnings, news updates, and situation reports, as well as the distribution of weekly summaries on volcanic systems. The public is encouraged to stay informed and prepared, as the situation may evolve rapidly.
