Volcanic Activity Near Grindavík: A Detailed Update
April 1: An Eruption Begins
On April 1, at 9:44 AM, a significant volcanic event unfolded north of Grindavík, with the emergence of a fissure that has been actively extending since the initial eruption. As of now, this eruption shows no signs of abating, and the fissure continues to shift southward.
The Latest on Magmatic Movement: April 8 Update
As of April 8, 16:15 UTC:
- Microseismic Activity: While there has been a decrease in seismic events close to the dike, ongoing microseismic activity indicates continued magmatic movements beneath the surface.
- Uplift Observations: Current measurements reveal substantial uplift below Svartsengi, occurring at a rate surpassing observations made after previous eruptions. This may be attributed to the recent release of approximately 30 million cubic meters of magma from the magma chamber.
- Future Predictions: While precise predictions concerning magma accumulation rates remain elusive, historical trends indicate that these rates typically decline over time, post-eruption.
Magma Intrusion
The latest calculations have confirmed that the April 1 event marked the largest magma intrusion since November 10, 2023. Approximately 30 million cubic meters of magma flowed into a newly formed dike. The persistence of seismic activity suggests that the volcanic threat in the Svartsengi region remains imminent.
Updated Hazard Assessments
The Icelandic Meteorological Office has conducted a comprehensive hazard evaluation, now valid until April 15, pending no significant changes. The assessment shows:
- Zone 3 (Sundhnúkur Crater Row): Reduced from “High” (red) to “Considerable” (orange).
- Zones 4 (Grindavík) and 5-7: These zones have shifted from “Considerable” (orange) to “Moderate” (yellow).
Despite the lowered hazard levels, ground collapse remains a concern, particularly near existing faults.
Observations from GPS and Seismic Data
Measurements from GPS stations highlight significant displacement and continue to inform experts about the ongoing activity. Uplift readings indicate that the northern part of the dike has extended nearly 4 kilometers north of Keilir, with notable fault movements observed within Grindavík.
Seismic Swarms and Implications
On April 3, a swarm of earthquakes was recorded near Trölladyngja, triggered likely by stress changes from the dike intrusion. This swarm included several notable quakes, with a peak magnitude of 3.9. Residents in nearby areas reported feeling these seismic events, a reminder of the dynamic nature of the region.
Conclusion: Continuous Monitoring Required
With magmatic accumulation still evident beneath Svartsengi, further intrusions and potential eruptions remain likely in the upcoming weeks. The Icelandic Meteorological Office will continue vigilant monitoring of seismic activities and deformation measurements to provide timely updates and guidance on safety measures.
As this situation unfolds, our commitment to keeping the public informed remains our priority. Individuals living near affected areas should heed advisories and remain aware of developments in volcanic activity and possible impacts on their safety and well-being.