REYKJANES PENINSULA, ICELAND - An approximately 200 meter long fissure has opened up to the SW of the first eruptive vents at Fagradalsfjall at approximately noon Iceland time on April 5th. The fissure opened up some 200 meters from a rescue and aid camp that was set up nearby, which was quickly dismantled and moved.
New fissure outbreak at Fagradalsfjall.
The new fissure can be seen below in relation to the main vent, with lave spilling down a valley to the ENE.
New fissure on the lower left. (Photographer unknown)
A new fissure opening likely indicates that this eruption is far from over, and that more fissure outbreaks are possible. Nothing in the data seemed to indicate anything like this was about to occur, so it comes as a shock to the scientists working on the data at Reykjanes Peninsula.
Camera 1 from FUV.is now points to the new fissure: Live from Geldingadalir volcano, Iceland - YouTube
Camera 2 is pointing at the older, main vents: Volcanic eruption in Iceland! Live - Monday 5th - Camera 2 - YouTube
Due to the dynamic nature of this eruption, people should take extreme caution, and heed the direction of authorities. New fissures opening in the area can do so without warning, as these typically don't produce much in the way of detectable seismicity or tremor.
Speculation has gone on for weeks whether this slow effusion of lava was going to peter out, but it seems as though this new volcanic system may be just getting started.
Some have theorized that the new fissure may decrease pressure on the original eruption site, and cause it to die out, but I'm not quite certain about that. The new lava breakout is at a higher elevation, so it stands to reason that there is still sufficient magma pressure in the dyke system to continue the effusive eruption at the original site. At this time, effusion remains steady, but lava fountaining is at a slightly lower level.
The new fissure is directly draining lava into a nearby valley named Meradali, where it is rapidly pooling on the valley floor, forming a lava delta.
Meradali valley with the new lava delta. Photographer unknown.
Maradali valley, like Geldingadaulur, is not close to any human settlements and lava is not expected to affect any structures or infrastructure at this time.
Gas emissions in the area are significant, and the area has been closed by authorities and will not open at 6am as normal. Residents in areas affected by vog (volcanic fog) should remain indoors, with their windows and doors shut. People with breathing conditions should not venture outside. Vog is SO2 gas, and when combined with moisture turns acidic and can damage the lungs.
Another webcam view of the fissure, with, presumably, the Geldingadaulur eruption to the left, and the newer fissure to the right (hard to tell):
*****UPDATE 3/5/2021*****
The new fissure continues to emit lava at a fast pace. This fissure seems to be stronger at onset than the previous fissure (now affectionately referred to as "bob", the new fissure is now called "Flo" tentatively by netizens). The smaller vents now appear to be inactive (the smaller of the two new fissures) or overcome by the lava flow as to mask its exhalations.
Lava is swiftly filling the below valley of Maradali, and previous service roads which earlier saw a procession of motor vehicles departing the area has now been overcome by the advancing flow. While it is difficult to tell from the webcam alone, probably some 5-10% of the valley floor is now covered by the new lava.
Lava continues to rapidly descend down the valley channel that was established early on. There are some indications of the formation of temporary or permanent lava tubes as flowing lava builds a chute of sorts as its cooling surface welds itself into a ceiling. These are prone to frequent collapse as lava flow rates change.
Dawn view of Maradali lava delta being emplaced by the new fissure (Screenshot from Ruv.is Youtube Feed).
The eruption at Geldingadaulur valley continues, with steady effusion of lava, and frequent collapse events from the brittle spatter cones which have formed into two distinct vents.
The 'right' vent (as seen on the current webcam view) continually builds a 'roof' which frequently collapses. It's lava fountaining level is muted by the fact that this roof develops, and over time, it is destroyed and rebuilt again.
The 'left' vent of "Bob" is prone to frequent crater wall collapses followed by periods of spattering that rebuild the collapsed structures. Despite predictions by some that this may eventually lead to a merged vent, I see this as unlikely due to the rate of spatter, and the fact that the camera angle at current does not really show the true distance between the left and right lava channels. It is about twice as far as it appears on camera.
The new fissure vents are rapidly building ramparts and creating the foundations for a larger cone, if the outside spatter begins building one. At current the lava has an easy path to the below valley of Maradali, however this flow can redirect at any time. It is possible that lava builds a levee or joint in the flow that begins to send lava in another direction.
The most likely channel for this is the 'rear' (or opposite of the current direction of flow) of the fissure. If the cone begins to build internal barriers from the other vents and create a 'compound cone', it is entirely possible that a lava 'spine' is created between two vents, deflecting ballistic lava bombs in the opposite direction.
Such a structure would be prone to frequent collapse, and and deflected lava bombs would likely be much cooler in temperature than lava directly issued by the vents. In this scenario, the 'rear' of the vent would likely issue more blocky-type lava flows consisting of shattered lava bombs and pahoehoe clinker, which would travel at a slow rate.
It is still to early to tell whether or not this new fissure has the staying power of "Bob", but the next 24-48 hours will likely shed a lot of light on the nature of the eruption.
*****UPDATE 4/6/2021*****
A third fissure has just opened up somewhere between "Bob" and "Flo. This occurred at 12:08am Iceland time. It opened suddenly and is currently issuing lava. The fissure is still expanding at the time of this writing, and it is unclear how large it may grow. The area it is erupting in is between Geldingagaulur, and Maradali.
The new vent can be seen nearly in between the 1st and 2nd eruptions.
Given this new development in such a short period of time from the "Flo" breakout (less than 48 hours), it is likely that the area will become off limits.
You can watch live feed of this eruption here: Live from Geldingadalir volcano, Iceland - YouTube
UPDATE 2:
The lava from the new fissure vent is rapidly approaching Geldingadaulur and is about to enter the valley. The vent opened quite close to Geldingadaulur.
The new vent can be seen to the far left, and the new flow moving towards Geldingadaulur.
It now becomes more probable that Geldingadaulur rapidly fills up, or at least at an increased pace, and may begin to flow into other valleys. It is also possible that more fissures can open along the same lineament as the three current eruptive vents.
Lava is encroaching on the MBL.is webcam, and it may be on borrowed time.
A replay was posted on Youtube from the original cam angle, showing the birth of the fissure. You can see it here.
The lava is of the same characteristics of all other fissures, and is part of the same system. If lava continues to drain into Geldingadaulur, it may redirect or augment the flow of the first vent, accelerating the filling and spillover of Geldingadaulur to adjacent valleys.
The lava pool from the 3rd fissure and the original Geldingadaulur fissure are now beginning to merge.
Activity at the original fissure appears to be reinvigorated with frequent fountaining, however the output seems to be a bit reduced in regards to lava outflow. It is hard to tell given that certain angles of observation are no longer available near the extremes of the new lava fields.
*****UPDATE 4/7/2021*****
The webcam run by MBL.is did indeed get consumed by lava last evening, as MBL reports.
Webcam views this morning are obscured by snowfall for the most part, but reveal that the new fissure has already begun to build a spatter cone. The valley of Meradali has been partially filled by the lava from the 2nd fissure, although its spread appears to have slowed considerably.
As weather is not good for viewing at current, and the area is likely off-limits to visitors, the webcams are the only monitoring source at this time.
An aerial shot was provided by MBL.is which gives a pretty good view of the three active vents.
From right to left, fissure 1, fissure 3, fissure 2.
A new lava field map has been issued which shows the approximate location of the new lava fields.
*****UPDATE 3/7/2021*****
The eruption may be coming to a close, but it is too early to tell. All three vents are now displaying a low level of activity according to webcam observations. The vents that have opoened up are only showing light spattering at the moment, and are not issuing any strong lava flows.
Screengrab from RUV.is' webcam showing non-eruptive activity.
While the original vent (Bob) still shows some spatter activity, it is now very subdued.
There are a few likely scenarios:
- The eruption is coming to an end and future eruptive activity might be preceded by further dyke intrusion events.
- The eruption is recharging after a gap in activity and may resume
- The eruption migrates to the NE and erupts in a new location
As of now, it is too soon to tell. The next few days and weeks will inevitably give more data.
*****UPDATE 4/8/2021*****
The eruption continues with renewed vigor this evening as the 1st and 2nd vent display elevated lava effusion. New lava flows from vent 2 are descending down the valleys once more, while vent 3 shows weak spattering and viscous lava flows. Vent 1 (Bob) is displaying constant pahoehoe flow, with weak spattering and occasionally strong ejections of lava bombs.
Flo Cam from RUV.is showing vent 3 at the right, vent 2 in the middle (faint) and vent 1 at the far left.
Vent 1 (BoB) showing weak lava bomb ejection with strong lava effusion.
Seismicity remains low with few quakes above 1.5 magnitude being detected. Within the last several hours, no detectable quakes on the peninsula have occurred.
From IMO - seismicity is low or nonexistent for the past several hours.
Tremor is also low. This could indicate that the eruption has stabilized, and that further dyke intrusions are not occurring at the moment. This can change at any time.
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