The December 9 Eruption: Significant Geological Activity in Iceland
Updated December 19 at 17:00 UTC
- Lava Coverage: The recent eruption covered approximately 9 km2, with a total volume of around 49 million m3.
- Ongoing Developments: Continuous magma accumulation is occurring beneath the Svartsengi region.
- Future Predictions: The likelihood of dike propagation will rise in the coming weeks if the magma accumulation rate holds steady.
- Updated Hazards: The hazard assessment has been revised and is valid until January 2, 2025.
- Current Hazard Level: Considerable risks remain at the eruption site.
Aerial surveys conducted on December 13 by the Icelandic Institute of Natural History and the Survey of Iceland revealed the latest eruption’s lava field, formed between November 20 and December 9, exhibits a total volume of 49.3 million cubic meters over an expanse of 9.0 square kilometers. The thickest lava deposits are noted near the craters and by the Blue Lagoon, with an average thickness of 5.5 meters.
A lava thickness map, derived from photogrammetric data, illustrates the extent of the recent eruption. The yellow zone marks the latest lava field, while the purple areas represent prior lava formations over the past year.
This eighteen-day eruption ranks as the second-largest in volume at the Sundhnúkur crater row since December 2023. The previous largest eruption occurred from August 22 to September 5, with a volume of 61.3 million cubic meters and an area of 15.8 square kilometers.
The accompanying graph compares the eruption durations (blue) and volumes (orange) at the Sundhnúkur crater row since December 2023, based on a collaboration including the Icelandic Civil Protection, Náttúrufræðistofnun, and the Icelandic Met Office.
December 18 marked one year since the onset of eruptions in this sequence along the Sundhnúksgígar fissure system. In total, seven eruptions have taken place, lasting a cumulative 114 days and producing around 216 million cubic meters of lava flows.
A captivating image captured during the December 18 eruption shows a stunning lava waterfall. Photo credit: Halldór Björnsson/IMO.
GPS data indicates that uplift in the Svartsengi region persists at a consistent rate, implying ongoing magma accumulation. Should this trend continue, it is anticipated that the likelihood of a dike intrusion will increase within weeks. The Icelandic Meteorological Office (IMO) continues to meticulously monitor the area’s activity. Should significant changes in magma accumulation or seismic activity arise, updates will be disseminated promptly.
In light of recent events, the IMOs hazard map has been updated and remains valid until January 2, 2025. This assessment particularly impacts the Sundhnúks crater row (Zone 3), where the hazard level has been downgraded from high (red) to considerable (orange).
Updated December 9 at 15:10 UTC
- Last Crater Activity: The last visible activity in the crater was detected via webcams around 7 a.m. on December 8.
- Drone Surveillance: No activity was observed during today’s drone flights over the area.
- Eruption Duration: The eruption lasted for 18 days.
- Hazard Assessments: The assessment has been updated.
Confirming findings from drone surveys conducted by Civil Protection, the east of Stóra-Skógfell eruption has concluded. The last visible glow from the crater was captured on webcams the morning of December 8. Over its 18-day duration, this eruption stands as the second-largest in terms of area among the seven eruptions since December 2023.
A recent photograph depicts the now peaceful crater, taken around noon. (Photo: Björn Oddsson – Civil Protection, National Commissioner of the Icelandic Police).
Ground uplift has been observed reinitiate around Svartsengi, a trend maintained over the past few days, confirming that magma accumulation has begun again beneath the region.
Displacement data from GPS stations around Svartsengi illustrates ongoing changes in the area’s elevation, emphasizing the importance of continuous monitoring in this geologically active region.
Gas Pollution Remains a Concern
Despite waning volcanic activity, gas pollution continues to pose a threat. Today’s gas dispersion forecasts predict light variable winds, making significant pollution less likely in the vicinity.
This weekend anticipates northerly winds on Saturday, shifting to southerly winds on Sunday, which may result in detectable gas levels in Vogur on Sunday.
Visitors are advised to keep a close watch on gas dispersion forecasts from the IMO and adhere to safety guidelines concerning air quality.
Updated Hazard Assessments
The hazard assessment has undergone revisions based on recent measurements. In Zone 1 (Svartsengi), the risk is now classified as “moderate” (yellow), down from “considerable” (orange). The revised assessment reflects the current situation where no lava flows are threatening the area. However, gas pollution remains a significant hazard across multiple zones, particularly in Zones 3, 5, and 6.
Photo taken by the IMO showcasing the lava river’s flow towards Fagradalsfjall, captured this morning.
Overall, continued vigilance is crucial as Iceland’s volcanic landscapes remain dynamic and captivating.