Magma Depressurised,Boiled & Raised,Iceland Svartsengi Fagradalsfjall Grindavik Litli-Hrútur Volcano

Land has risen rapidly at Svartsengi in the last few days, much faster than before the earthquake on November 10. The center of the land giant is near Svartsengi. Pressure dropped significantly when magma flowed from the area, east under Grindavíkurveg and over to the Sundhnúka crater series. The magma tunnel stretches under Grindavík and out to sea in a southwesterly direction.

Freysteinn Sigmundsson, a geophysicist at the University of Iceland, says:
"When the pressure drops, favorable conditions are created for the magma to re-establish itself in this area. The most likely explanation for this is that magma is flowing into this magma accumulation area that had formed before," says Freysteinn.

Scientists have been watching the land rise this week, but it wasn't until the weekend that the signals became clear and distinct because the continued movements of the magma tunnel disturbed the measurements.


https://www.mbl.is/frettir/innlent/2023/11/20/kvika_streymir_a_ny_undir_svartsengi/

Since midnight today, over 700 earthquakes have been detected in the region of the magma intrusion, the largest of which was magnitude 2.7 near to Hagafell.

In recent days, between 1,500 and 1,800 daily earthquakes have been measured in the region, with the largest event registering magnitude 3.0 last Friday (17 November). Based on radar imagery from 18 and 19 November 2023, the latest interferogram of the magma intrusion and the surrounding area shows significant crustal uplift in the vicinity of Svartsengi. The newly processed interferogram was reviewed by experts during the weekend (18 – 19 November) from the Icelandic Meteorological Office, the University of Iceland, and the Department of Civil Protection and Emergency Management. The results were also discussed in today's status meeting, held at IMO. The rapid, ongoing uplift close to Svartsengi is occurring in the same area where uplift was measured before the magma intrusion formed on November 10. Geodetic models derived from satellite images show that the uplift in Svartsengi area is considerably faster than before. Generally, when a magma intrusion forms, subsidence occurs above the centreline of the intrusion, as seen in Grindavík, with signs of land uplift discernible adjacent to the intrusion. Crustal uplift in the Svartsengi region due to magma accumulating at depth has been measurable since the intrusion began to form on 10 November. Initially, the uplift sign was influenced by the formation of the intrusion, but now the dominance of deep magma recharge is apparent.

The clear sign of crustal uplift in Svartsengi region does not change the likelihood of an eruption from the magma intrusion. This is assessed, amongst other things, on the fact that the Earth's crust over the magma intrusion is much weaker than the crust over the uplift region close to Svartsengi. As long as there is not significant seismicity in the Svartsengi region, there is not a high likelihood of an eruption at that location. Moreover, an eruption is still deemed more likely from the intrusion, particularly if there is a sudden, large inflow of magma into the intrusion.

Our monitoring and hazard assessment preparations are still based on the assumption that the situation could change suddenly with little warning. The Icelandic Meteorological Office, in close cooperation with experts from the University of Iceland, will continue to monitor the area closely, with the goal of continually interpreting and evaluating all available monitoring observations.
https://en.vedur.is/about-imo/news/a-seismic-swarm-started-north-of-grindavik-last-night