In Iceland, the 3rd volcanic eruption of the Reykjanes volcano this year is almost certain
to occur by the end of the week.
And, when it does occur, there may be as little as 30 mintues of warning beforehand.
At the 5 kilometer or 3.1 mile depth magma chamber 1100 meters south of the Svartsengi
Geothermal Power Plant, magma is building in volume at a rate of approximately 4.3 cubic
meters per second.
Due to the seemingly repetitive nature of Reykjanes's overall volcanic activity since
October of 2023, it appears that a new volcanic eruption is most likely to occur between March
1st and March 3rd of 2024.
Although we do not know where exactly magma is most likely to erupt from, a number of
possibilities have been simulated to determine which areas are most at risk.
While a worst case scenario would involve either an explosive eruption occurring in
the ocean or lava erupting in the middle of the town of Grindavik, the most likely outcomes
involve lava erupting from a fissure in a similar location to its prior 3 eruptions
since last December.
One location which is receiving potential note is the possibility involving an eruption
occurring just west rather than east of the feature known as Hagafell.
If an eruption did begin there, there are two potential danger zones to keep an eye
out for where you do not want lava to flow.
The first is a narrow zone towards the east which has the potential to flow around the
existing lava barrier to the east and potentially hit structures.
The second possibility is more likely and involves lava flowing beyond the reach of
the January 2024 eruption lava field, hugging the lava wall until it goes beyond it, potentially
striking outlying structures within Grindavik.
Although there is no truly safe location for an eruption to begin, the further north you
go on the 15 kilometer underlying magma tunnel, generally speaking the less destructive of
an outcome there will be.
If lava instead erupted to the north of the white path I have drawn, then it would be
quite likely to recover roads overflowed by lava earlier this month, and in a worst case
scenario potentially advance onto a section of the Blue Lagoon's parking lot.
Due to the increased likelihood of an eruption occurring, the Reykjanes volcano's hazard
map has been updated, with a general hazard level increase in most areas.
Currently, magma has pooled to a volume of approximately 7.6 million cubic meters in
the shallow magma chamber.
For reference, all of Reykjanes's recent eruptions have occurred when this very body of magma
was filled to a volume of between 8.6 million and 16.8 million cubic meters.
However, I have something quite interesting to note.
Ever since November 10th, the rate of magma going into the underlying magma chamber has
been progressively decreasing, going from 6.94 cubic meters per second leading up to
the first eruption to 4.33 cubic meters per second leading up to the last eruption.
Additionally, the volume of magma required to trigger a so-called magma run event has
also been progressively decreasing and I believe I know why this is occurring.
My interpretation is that magma is increasingly sticking to the edges and especially the bottom
of the magma chamber, causing it to grow narrower and narrower as the weeks and months progress.
If this pattern continues, between 6 and 10 eruptions from now there will be no magma
chamber to fill, potentially causing molten rock to seek a new path to the surface.
The simplest path would be a preexisting one towards the east, causing it to develop in
another area.
However, it could also travel upwards and erupt directly south of the Svartsengi Geothermal
Power Plant.
While this is not yet believed to be a hazard, eruptions from this volcano are getting more
frequent due to the progressively smaller size of the existing magma chamber, occurring
about 2 days earlier each time than the time between the two prior magma run events.
As a final note, I would like to thank my new patron Jeffey Saff for supporting this
channel!