A robust earthquake swarm has begun on the Reykjanes Peninsula, Iceland. Practically 4000 earthquakes have been detected within the first 24 hours, with the exercise persevering with at a robust tempo. First knowledge additionally exhibits tremor alerts, indicating that the exercise is probably going as a result of magma motion under the bottom.
This has prompted the officers to lift the alert stage within the space. An eruption is probably going, with the prospect rising steadily because the earthquake exercise continues.
WHERE FIRE MEETS ICE
Iceland is a volcanic island within the North Atlantic and probably the most lively volcanic areas on the earth. In its historical past, it produced important eruptions with highly effective impacts on Europe, North America, and your complete 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).
The picture under exhibits the spreading tectonic plates and the place the Mid-Atlantic Ridge passes by means of Iceland. It enters the southwest on the Reykjanes Peninsula, going to the east and turning north. Crimson triangles present the principle central volcanoes.
However the tectonic plates unfold aside down throughout your complete Atlantic Ocean. So why is that this location so distinctive, producing a big volcanic island over 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.
Under is a picture that exhibits the approximate middle of the place the plume connects with Iceland below the Vatnajokull glacier (black circle). You can even see the mid-Atlantic ridge in orange and volcano places.
However our focus is on the southwestern area, referred to as the Reykjanes Peninsula. Under you may see this space, together with the earthquake exercise earlier than the newest swarm started. It has regular background tectonic exercise.
That is additionally the place of the final eruption in Iceland, with the brand new earthquake exercise being very near the eruption space.
THE LAST ERUPTION
There may be often a volcanic eruption in Iceland each 4 to six years. The final eruption started on March nineteenth, 2021, and resulted in mid-September. This eruption was a extra lava stream from the Fagradalsfjall volcanic space. The eruption space is discovered on the Reykjanes Peninsula in southwest Iceland, as seen within the picture under by the Icelandic Meteorological Workplace (IMO).
Under is a picture of the lava subject in the course of the eruption. The eruptive cones had been glowing purple, whereas the erupted lava was 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. Picture by: Almannavarnir/Björn Oddsson.
The Icelandic Met Workplace (IMO) studies that round 151 million cubic meters of lava erupted (5.3 billion cu ft), protecting 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 subject.
EARTHQUAKE ACTIVITY BEFORE ERUPTION
The entire sequence started with an earthquake swarm on February twenty fourth. The strongest earthquake within the preliminary swarm had a 5.8 magnitude. There have been additionally quite a few M3 and M4 earthquakes in that swarm and plenty of robust aftershocks. The shaking was strongly felt all the best way to the capital Reykjavik.
Greater than 20.000 earthquakes have been recorded with the Icelandic Meteorological Workplace’s computerized seismic measuring system two weeks after the beginning of the earthquake swarm.
The preliminary swarm had robust magnitude earthquakes unfold out, targeted into two clusters. Cluster 1 was related to the Fagradalsfjall volcanic system, and cluster 2 was related to the Krysuvik volcanic system, which later quieted down.
By February twenty seventh, the principle earthquake exercise was targeted on the west cluster within the Fagradalsfjall volcanic system. Frequent magnitude 4 earthquakes had been detected. Shaking from the stronger earthquakes was felt throughout the area, all the best way to the capital Reykjavik.
The graph under exhibits the earthquake exercise on the peninsula up to now 2 weeks. Because the onset of the principle swarm on February twenty fourth, the earthquakes continued with frequent magnitude 4 and 5 earthquakes.
The earthquake evaluation for the interval as much as the swarm exhibits that this area is below fixed shaking. You’ll be able to see the earthquake swarm from February/March on the finish and the way highly effective it was in comparison with the earlier exercise, releasing extra power than mixed within the final a long time.
However an analogous space has now re-ignited with robust earthquakes and a big earthquake swarm.
LATEST EARTHQUAKE ACTIVITY 2022
At present, we once more have new exercise on the Reykjanes peninsula, in southwest Iceland, simply northeast of the earlier eruption website.
On July thirtieth, a robust seismic swarm has begun simply northeast of Fagradalsfjall. Set off earthquakes are occurring east and west of Fagradalsfjall. The exercise began round midday, and since then, almost 4000 earthquakes have been recorded on the IMO’s computerized system.
Probably the most important occasion up to now had a preliminary magnitude of M5.4 with a depth of round 2 km (1.2 miles) and occurred on July thirty first. Primarily based on the accessible knowledge, this new earthquake exercise is triggered by magma motion at a depth of round 5 to 7 km (3 – 4 miles).
The video under exhibits the shaking of the digital camera after being hit by a Magnitude 5+ earthquake on the Reykjanes Peninsula in Iceland. You’ll be able to see the steaming from the crater of the Geldingadalir volcano. This video was taken with a webcam from mbl.is.
Within the picture under, you may see the preliminary earthquake burst on July thirtieth. It’s positioned simply to the northeast of the lava subject produced by the eruption final 12 months.
Latest deformation observations additionally affirm that this exercise is probably going brought on by magma intrusion. Preliminary modeling outcomes point out the supply is positioned at a depth of between 4-5 km.
EARTHQUAKE SWARM 2022
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. Total, we are able to see the earthquake exercise up to now 8 days.
With the final 8 days of earthquake exercise on the map under, we are able to see the robust exercise from the brand new earthquake swarm (0-2 days outdated). Each the Fagradalsfjall volcanic system and the Krysuvik volcanic system are at the moment experiencing elevated earthquake exercise.
We will see this by zooming additional into the purple sq.. This revealed that many of the exercise is definitely positioned northeast of Fagradalsfjall. That’s the location of the eruption final 12 months.
There are lots of seismographs on this area, so monitoring is great. Under we’ve a seismograph studying from the Grindavik space, near the exercise. You’ll be able to see many earthquakes, all the way down to the micro-seismicity. The strongest wave is the M5.4 earthquake, the most important detected up to now.
Wanting on the decrease frequency plot, we are able to see robust power additionally within the decrease frequencies. This does point out that there’s extra than simply rock breaking happening. Low-frequency alerts can point out fluid motion, which on this case means magma at depth.
The graph under exhibits that almost 500 earthquakes have been manually reviewed and positioned within the second half of July. However in whole, almost 4000 seismic occasions have been detected by the monitoring stations within the final 2 days alone.
The automated earthquake detection system could be very delicate and picks up even on weak exercise. However the automated knowledge isn’t that correct. So guide overview is critical to refine the situation and depth of every earthquake, which is a time-consuming course of.
Wanting on the final 48 hours, we are able to see that the exercise is ongoing at a gradual tempo. The picture exhibits each the manually reviewed earthquakes and the auto-detected occasions. Not all of the occasions are proven on the map, as quite a bit are too small to be correctly positioned and plotted however are seen on the seismograph.
You’ll be able to see within the picture under how the tremor alerts are being recorded throughout the nation. The picture exhibits alerts from particular person monitoring stations throughout Iceland. The tremor alerts are robust sufficient to be detected throughout the nation, with alerts from stronger occasions reaching far internationally.
Talking of a seismograph, there’s a particular plot that exhibits the frequency of shaking and the related depth. Within the picture under, we’ve excessive, medium, and low-frequency alerts from a monitoring station close by.
It exhibits a good and steady tremor sign related to the earthquake swarm. That is additionally an indication of the magma motion being a consider these occasions.
FROM GREEN TO YELLOW LEVEL
In gentle of the elevated seismic exercise and floor deformation, the Krýsuvík-Trölladyngja volcanic system was elevated from GREEN to the YELLOW aviation code stage. Earthquake exercise and speedy inflation are at all times a reason for concern with volcanoes, so the next alert stage is anticipated if the exercise continues.
The ultimate graphic exhibits the projected path that lava may absorb a possible bigger eruption in the principle earthquake space. That is only a simulation based mostly on the present identified info and historic knowledge.
An eruption isn’t but sure at this level, however the longer the earthquake exercise continues, the upper the prospect of an eruption turns into.
It will take a robust eruption to supply sufficient fuel to succeed in Europe in dangerous focus. It has occurred up to now, with lethal penalties, and it might occur once more sooner or later.
But when an eruption does occur, it isn’t at the moment projected to supply such robust concentrations of volcanic gases.
There may be additionally a risk that the earthquake exercise may slowly scale back, ending with no eruption.
The official company in Iceland for monitoring volcanoes is the Icelandic Meteorological Workplace (IMO), the place you’ll find dwell knowledge, extra info, and all official warnings.
We are going to preserve you up to date as recent knowledge is obtainable and extra dependable projections will be made.
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