One other volcano in Iceland is on an elevated alert after an earthquake swarm and floor motion. As well as, the accessible knowledge exhibits that magma is accumulating beneath the volcano, steadily rising the chance of an eruption within the close to future.
However as you will notice, there may be multiple volcano able to erupt in Iceland. Furthermore, there’s a recognized historical past of widespread results on Europe and throughout the Northern Hemisphere from Icelandic eruptions. Because of this, every occasion is being monitored intently and brought significantly.
FIRE MEETS ICE
Iceland is a volcanic island within the North Atlantic and one of the vital lively volcanic areas on this planet. In its historical past, it produced vital eruptions with highly effective impacts on Europe, North America, and your entire Northern Hemisphere.
The island experiences fixed earthquake exercise as a result of it sits on the boundary between the Eurasian and North American tectonic plates. This boundary is also referred to as the Mid-Atlantic Ridge (MAR).
Because the plates transfer away from one another, they successfully tear the island aside. Iceland is the one place the place the Mid-Atlantic Ridge rises above the ocean floor.
The picture under exhibits the spreading tectonic plates and the place the Mid-Atlantic Ridge passes by Iceland. It enters the southwest on the Reykjanes Peninsula, going to the east and turning north. Purple triangles present the principle central volcanoes.
However the tectonic plates unfold aside down throughout your entire Atlantic Ocean. So why is that this location so distinctive, producing a big volcanic island over the thousands and thousands of years?
The reply is a vertical plume of scorching molten rock from the mantle, additionally referred to as a hotspot or a Mantle plume. In depth research have proved that it lies beneath Iceland. Subsequently, it’s extra generally referred to as the Icelandic plume. The picture under is a graphical presentation of the rising mantle plume beneath Iceland.
The high-pressure magma from the depths of the Earth has discovered its method to the floor with this plume. Following the trail of least resistance, it pushed by the cracks between the spreading tectonic plates, beginning to construct an island.
We will see the Earth’s terrain with out the oceans within the picture under. You may see the Mid-Atlantic ridge coming from the southwest. And likewise, you possibly can see the big “lava pillow” of kinds on which Iceland sits. It was produced because the mantle plume pushed by the spreading tectonic plates.
The plume has pulses or cycles, inflicting intervals of upper and decrease volcanic exercise in Iceland. We’ve entered a brand new interval of elevated exercise in recent times/a long time. However whereas the plume lies beneath the entire of Iceland, its middle is beneath the biggest Icelandic glacier referred to as Vatnajokull.
Under is a picture that exhibits the approximate middle of the place the plume connects with Iceland beneath the Vatnajokull glacier (black circle). You can too see the mid-Atlantic ridge in orange and volcano places.
Vatnajokull is the biggest glacier in Iceland and the biggest ice cap in Europe. It covers roughly round 7.900 km2 however is now decreasing over time. Beneath this glacier, many alternative volcanoes are hidden, coated by a whole lot of meters of stable ice and snow. The picture under exhibits the principle central volcanoes beneath northwest Vatnajokull.
THE LAST ERUPTION
There’s normally a volcanic eruption in Iceland each 4-6 years. The final eruption started on March nineteenth, 2021, and resulted in mid-September. This eruption was a extra peaceable lava stream within the Fagradalsfjall volcanic space. This space is discovered on the Reykjanes Ridge in southwest Iceland, as seen within the picture under by the Icelandic Meteorological Workplace (IMO).
Under is a picture of the lava area throughout the eruption. The eruptive cones are glowing purple, whereas the erupted lava is already cooling and turning darkish within the course of. There was near-constant lava spattering from the vents, which have been constructing cones above the eruption factors. Photograph by: Almannavarnir/Björn Oddsson.
Under is a video animation that exhibits the earthquake sequence within the first days of the earthquake swarm. It covers the interval from February twenty third to March 2nd, 2021. You may see intense bursts of earthquakes and fairly violent ground-cracking exercise.
The Icelandic Met Workplace (IMO) experiences that round 151 million cubic meters of lava erupted (5.3 billion cu ft), overlaying an space of roughly 4.8 km2 (1.9 sq. miles). Under is a map from @geoviews that exhibits the eruption cones (triangles) and the ultimate unfold of the lava area.
NEW VOLCANIC ACTIVITY 2022
However Iceland is at all times lively in some form or type. Presently, we’ve got new exercise on the Reykjanes peninsula, in southwest Iceland, round Mt Thorbjorn.
In mid-Could, greater than 3000 earthquakes have been mechanically detected within the Reykjanes/Svartsengi volcanic system. Essentially the most vital occasion had a magnitude of M4.3 and occurred on Could fifteenth. The seismicity is positioned at a depth between 4 and 6 km.
Current deformation observations (each GPS and InSAR) recognized the onset of a brand new inflation occasion west of Mt Thorbjorn, seemingly brought on by magma intrusion. Preliminary modeling outcomes point out the supply is positioned at a depth of between 4-5 km.
Up to now month, seismographs detected almost 9000 earthquakes within the space, largely associated to underground volcanic exercise.
The Reykjanes area lies within the southwestern nook of Iceland. Within the picture under, we are able to see the Reykjanes Peninsula marked. This space experiences near-constant earthquake exercise, together with occasional stronger occasions.
We’ve the final 30 days of earthquake exercise on the map under. The principle batch of seismic exercise is at the moment centered across the Grindavik space. Colour coding tells us the age of the seismic occasions, which signifies that currently, earthquakes have been centered extra on the Mt Thorbjorn space.
We will see this by zooming additional into the purple sq.. Based mostly on the colours, a separate seismic occasion occurred to the west round three weeks again. The newest exercise is principally centered across the Mt Thorbjorn/Grindavik space, extending to the northeast.
There are various seismographs on this area, so monitoring is superb. Under we’ve got an instance seismograph studying from the Grindavik space. You may see many earthquakes, all the way down to the micro-seismicity. Some occasions are too weak to be positioned, however they nonetheless depend as detected.
The graph under exhibits that over 1600 earthquakes have been manually reviewed and positioned within the second half of Could. However in complete, over 6000 seismic occasions have been detected by the monitoring stations on this interval.
Trying on the final 48 hours, we are able to see that the exercise is ongoing however at a lowered tempo. Round 100 earthquakes each day happen on this space, whereas round 800 occasions per day have been recorded on the peak exercise.
Floor motion across the volcano also can inform us so much in regards to the exercise. We have to discover indicators that earthquakes are brought on by the recent scorching magma coming into the volcanic system underground, accumulating and rising the stress within the volcano.
Like inflating a balloon till it explodes, the magma accumulating beneath the volcano will increase stress. The method of floor deformation brought on by magma accumulation is named inflation.
Under we’ve got a satellite tv for pc remark of floor motion throughout the peak of the earthquake exercise within the Grindavik space. We will see a transparent uplift sign, which signifies that magma accumulates underground. From April twenty eighth to Could twenty eighth, the land rose by greater than 5 cm (2 inches) and was co-occurring with vital seismic exercise.
There are additionally many GPS stations on the bottom which monitor floor motion with nice accuracy. For instance, we’ve got the vertical GPS knowledge under, which exhibits a fast inflation interval at Mt Thorbjorn since late April.
Elevated seismicity and inflation sign that the underlying course of should be magmatic. Knowledge evaluation and modeling counsel that the deformation supply is positioned round 4-5km deep.
ALERT LEVEL RAISED
In mild of the elevated seismic exercise and the continued deformation within the Reykjanes/Svartsengi volcanic system, the aviation colour code was elevated from GREEN to YELLOW. Earthquake exercise and fast inflation are at all times a reason behind concern with volcanoes, so a better alert stage is anticipated.
ROAD TO ERUPTION
However this exercise just isn’t new on this area. For instance, in 2020, an analogous occasion occurred in the identical space: elevated seismicity and floor deformation at an equal depth. Under we’ve got the earthquake swarm ongoing in early February 2020.
The strongest earthquakes ranged from magnitude M3 to over magnitude M4 occasions, just like the present occasion. The whole variety of earthquakes was smaller, however the power output of the swarm was not a lot decrease.
The graphic under, supplied by Iceland Met Workplace, exhibits the bottom inflation between the 18th and twenty fourth of January 2020, as measured by the Sentinel-1 satellite tv for pc and calculated with the InSAR method. We will see that the inflation occurred in the identical space as now.
We will safely say that this appears to be an analogous occasion with the identical trigger. Magma is accumulating beneath Mt Thorbjorn, at round 4-5km depth. This doesn’t point out that an eruption is imminent. However every such occasion of seismicity and inflation will push the volcano nearer to an eruption.
However there may be one other volcano in Iceland that can be on yellow alert and has a violent previous. That’s the Askja volcano.
ERUPTION RISK AT ASKJA VOLCANO
Within the picture under, we’ve got a map that exhibits the principle central volcanoes in Iceland. We will see the yellow alerts on the Reykjanes peninsula, and marked in purple is the Askja volcano on a yellow alert.
The Askja volcanic system is a part of the Northern Volcanic Zone. It’s round 190 km lengthy and as much as 20 km broad, consisting of a central volcano rising to 1516 m (4973 ft) a.s.l. and a fissure swarm. A caldera advanced lies throughout the central volcano. The youngest caldera is the Öskjuvatn caldera, now occupied by a lake.
The picture under exhibits the Askja central volcano and its associated fissure swarm. The pink and violet areas mark the previous lava flows from this volcano. It primarily erupts in an effusive fashion however has a recognized historical past of extra vital explosive eruptions from the principle crater.
Within the picture under by IMO, we are able to see the Askja volcano, which is extra of a caldera advanced. The crater lake shaped throughout its final massive explosive eruption in 1875, when ash was deposited over Europe.
We will see the extent of the ash deposits from the 1875 Askja eruption within the picture under. A big a part of Scandinavia had volcanic ash deposits. The ash cloud was carried over a lot of Europe and the North Atlantic and would trigger severe issues if such an eruption occurred once more.
For instance, we used the NOAA Hysplit mannequin to supply an eruption simulation. The picture under exhibits the air motion trajectories for an explosive eruption beginning early subsequent week and lasting for 3 days. The elevation is ready at 10km (6.2 miles), overlaying the cruising altitude of air site visitors.
In a big eruption, the climate sample would carry the ash cloud instantly into northern Europe. Such an occasion would shut the airspace over the area and sure over different components of Europe.
Because of its highly effective previous, we’re preserving a detailed eye on the Askja volcano. Under we’ve got the earthquake exercise in 2022 up to now. We will see a lot of the seismic exercise centered round the principle crater. Nevertheless, deeper earthquakes happen to the north and northeast, the place its magma supply is deep under the bottom.
However what’s extra placing is the bottom deformation. For the reason that finish of final summer season, the bottom at Askja has raised by 30cm (12 inches). It is a vital quantity and exhibits that the system is pressurizing.
The GPS plot under exhibits the vertical floor motion in Askja since final August. Once more, we are able to see that inflation is ongoing at a secure, quick tempo.
Askja is one other instance of earthquake exercise occurring with uplift at a volcano. There generally is a legit purpose for concern about an eruption after we see such alerts.
Most such occasions by no means trigger an eruption however present that the system is pressurizing. Nevertheless, the stress rises to a crucial stage at a sure level and may provoke an eruption. So we’ve got to deal with every such occasion as a possible hazard.
We have no idea which such occasion would be the final one which places the volcano right into a crucial stress part. So monitoring is crucial, and fortunately, Iceland has a number of the greatest monitoring gear on the sphere.
We are going to maintain a detailed eye on Askja and all of the volcanoes in Iceland, informing you of any vital growth. The official company in Iceland for monitoring volcanoes is the Icelandic Meteorological Workplace (IMO), the place you will discover dwell knowledge, extra info, and all official warnings.
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