The parasitic vent, Aug 9
Over the past weeks, the Fagradalsfjall has settled into in almost predictable routine. There are regular cycles of eruptions and interruptions. During the interruption, the tremor goes quiet. Nothing is shaking or moving on the drum plots. Over several hours, there is a slow build-up of the tremor. Lava begins to return to the crater in this phase. It reaches a peak when the crater is full and is vigorously bubbling. The crater overflows and the lava moves down the slopes, towards Meradalir. After 10 to 16 hours, the tremor very suddenly stops. The drump lot goes flat, and within minutes the lava disappears. A quiet, lava-free period begins; the cone is dark and empty. It stays likes this for perhaps 10 hours, the build-up starts and the cycle repeats. The build-up is slow but the end is almost instantaneous. In one case we saw that the end was triggered by a small wall collapse. The complete cycle takes about 1.5 days, or at least has done for the past week or so.
There are many drone videos of the eruption. Here is one that shows the phase of high activity. The vigorous bubbling occurs on one side of the crater, and it has build up a higher slope on this side.
Boom
During one of those quiet periods, there was a surprise. This was perhaps not unexpected. As one commenter wrote “This volcano keeps doing something different every few hours. Wouldn’t shock me if it started belching out wildflowers for a bit.” To be precise, a big bang. It was brief, and it was after midnight while nothing much was going on. The flash was still noted by the ever-present army of watchers, who see with blinding sight. After the flash, a gap was seen in the rim of the crater. The next day, lava flowed through this gap but it was quickly repaired by the eruption.
Here is the recording of the flash.
The flash came from the same area of the cone where the bubbling occurred during the active phase. It was not at the location of the gap and it seems this gap may have formed before the explosion, not during it.
Explosions are not uncommon during a phase where an eruption tapers off. The lava retreats below a blockage, either rubble or a thin surface of solidified lava no longer broken up by the movement of bubbles. Gas can collect below the blockage, and once the pressure become too much, cause an explosion. We have seen this happen in Agung. One explosion in the night is not yet a pattern, but it is a warning. Do not assume the cone is safe even during its sleepy time.
Gentle into that good night
Is it possible that the eruption is waning? Recent activity episodes have not been as vigorous. The lava does not get as far in Meradalir and instead spends more time building up the shield on the old valley-with-no-name which now is almost a hill-with-no-name. Where there used to be a lava river running down the slope, now there are many braided channels. Carl noted that the low-frequency tremor is beginning to lag behind the high frequency, and that the build-up phase takes longer. It is appearing as an eruption in decline. The coastal road may yet be safe.
The latest report can be found at http://jardvis.hi.is/eldgos_i_fagradalsfjalli, with data taken on August 8. They find that the flow rate is a bit lower, 9.3 m3/s averaged over 12 days. The rate has fluctuated over the past month. The scientists write ‘There are strong indications that the flow was lower in the first half of July, 7-9 m3/s, but then came a peak that lasted for 8-10 days, where the flow could have reached 17 -18 m3/s on average.’ It is too early to call an end, but the eruption is having difficulty in keeping going. Was the explosion its Rage, rage against the dying of the light?
Quarantine
In spite of its difficulties, it is already an impressive eruption. The volume has reached 0.12 km3; the area that is covered by lava is now 4.4 km2. The area has increased little in recent weeks, because it is locked in by the walls of Meradalir. Will it manage to break out?
The last few days have had fairly clear weather, a notable difference to the dense fogs of July. This has allowed some useful satellite images, not entirely cloud-free but giving us a complete overview of the lava fields. This satellite image is from August 7, taken with the ESA Sentinel. It was during a vigorous lava flow into Meradalir; the red flows dominate the image. How far did these flows get?
It is easy to recognize the hot lava. In contrast, the cold lava is black, not the easiest colour for images, and not easy to distinguish from the surrounding burned vegetation. We can see that the flows went into Meradalir, but to see whether they expanded the flow field requires a better comparison.
The current full extent of the lava flow can be found at http://www.viewsoftheworld.net/?p=5783 together with detailed contour levels. Taking that map and overlaying it with the satellite image shows where the recent flows reached the walls. This did happen but only at a few places. The flow is pushing the edges in the northern most lobe and it may still be expanding there. The only other place was on the eastern side of the northern lobe but there it is pushing against a hill – it can go up but not out. It is possible there is some further lava movement underneath the surface which is hidden from our view. But mostly it seems that the lava likes to stay in the upper reaches of Meradalir.
In the western part of Meradalir, the elevation of the lava now reaches 150, in places 160, meters. There is a 20 meter drop in level around the narrow part of the valley. In the north-south-oriented valley to the east, the lava has reached an elevation of 130 meter. Northward it still has to inflate by 20 meters to escape: Meradalir there is enclosed by the 150 meter contour. To the east and south there are some escape routes at 140-145 meters elevation. The lava is still some ways short and it won’t escape the valley until the lava flows reach these borders again.
Instead, much of the lava seems to be building up the shield in front of the cone, and also thicken the slope into Meradalir and the upper valley. It is not as mobile as it used to, either because of lower flow rates or because of higher viscosity. It is getting old, but still going. Old age should burn and rave.
For enjoyment, here is another recent satellite image. This was taken by Planet Labs, also on Aug 7 but during the quiet phase. The high resolution image can be found at https://postimg.cc/w1JWNddj It shows more detail, including the shape of the cone
Finally, the 3d overview always adds to the information:
Rhymes and Reasons
So why is the output currently cyclic? Why is it variable? Is this an old eruption needing its daily naps?
Let’s start with volcano basics, VC 101. The magma flow is determined by a combination of factors (ok, VC 102). One is the magma itself: the overpressure it is subject to, and the buoyancy. The other is the conduit: the capacity of the conduit is set by its width and by the viscosity of the magma, perhaps reduced further in places by bottle necks.
Originally the flow was fed by the magma dike that was emplaced in February and March. The conduit connected this dike to the surface, and it limited the flow rate to 5-7 m3/s. The increase in the flow rate came in April when a new vent opened, with (apparently) a wider conduit. The dike probably contained around 0.1-0.5 km3, within range of what has erupted so far. Whether the eruption is purely living of this magma emplaced in the dike or that it has direct access to magma from deeper down is unclear. If it is the former, then we may now be in the winding-down phase where the pressure is decreasing and the viscosity may be increasing. If the latter, then it could continue as we are for longer. Of course, if it did stop the pressure in the dike could still force another opening elsewhere to give it another (shorter) lease of life. And volcanoes have been known to push out a block viscous magma to restart the faster flow. The problem with predicting the future is that there are too many possibilities. There is a butterfly effect for the weather – perhaps there is an earthworm effect for volcanoes.
Local GPS stations, e.g. Krysuvik and Svartsengi, indicate a small amount of deflation, with the stations moving a bit closer (1-2cm) to the eruption site since May, and since mid July also showing downward motion of some 2 cm. Svartengi is almost back to the elevation it had before March. Krysuvik still retains more than half of its elevation gain. This tells us that the deeper magma (perhaps 5 km or more) may have lost some volume but the shallow dike is still there. Of course it may have partly solidified.
The rapid fluctuations in flow rate suggest that the magma flow is no longer limited purely by the conduit but that maintaining pressure is becoming a problem. The most likely cause for the sudden interruptions is that something is quenching the degassing. Gas bubbles make the magma buoyant, and if they suddenly dissolve back into the liquid the magma column will collapse. The fact the cycle is fairly regular indicates it is not due to random effects, but it is running out of gas. Once it is running low, and small disturbance which adds weight to the column (rubble falling down) can stop the eruption. Now it takes time for gas to be replenished from below, carried up by fresh magma. Bubbles slowly reform, the column rises and the eruption restarts.
Where does this happen? The degassing is mainly in the lava pond inside the cone. If the pond has a size of 100 by 50 meters, it would need to be around 100 meter deep to provide the amount of lava erupted in one cycle. This is a rather rough number but let’s assume that in the quiescent phase, lava withdraws to that depth. That means that without the aid of the gas bubbles the magma column would reach to 100 meter below the rim of the cone. This is the height reached by the pressure in the dike or conduit, and it is not sufficient to drive an eruption. The cone has grown much too tall for the eruption. The eruption is at risk of ending itself by over-ambition. It may explain the parasitic vent, by the way, as the capillary action of the rubble of the sides of the cone can aid the rising of the lava.
Aug 12
Aug 10
The cone is currently not increasing in height. The region around the cone is growing, and is doing so rapidly. You can see this by staring at the above images taken on Aug 10 and Aug 12, or easier from this animation close-up from the Meradalir camera. The shield to the left is notably growing: you can see how the two hills immediate to left left of the cone are disappearing behind the shield. (One is now only barely visible.) Much of the lava is currently going into building the shield and not into the valley. But the cone itself is not changing (and neither is the region to the right). It indicates that the cone has reached its maximum height: the magma has insufficient pressure to go higher.
This suggests a way the eruption could re-invigorate: get rid of the cone. A new outlet at the base of the cone would change the state of play and could restart a phase of continuous, perhaps even vigorous (if not too viscous) flow. Could the cone collapse? So far it has avoided that – not even the explosion did much damage. But this volcano is unpredictable. Creating a new eruption site is harder as it has to break a new conduit through the solid rock. That will only happen if the eruption stops completely and the current conduit blocks. The pressure inside will build up, and eventually a new fissure may form. Or if the energy is gone, Fagradalsfjall may fall silent again, for 10,000 years or more.
Helicopter view
The drum plot show the phase of low activity, the build-up and the high activity. You also see intermittent brief bursts of activity, lasting perhaps 20 seconds. These puzzled us for a while. They are seen at any phase, but only during day light – were they solar-induced? They are on a 2-hour schedule (notice the repeating colours), starting around 10am. We now think these are helicopters flying over the seismograph.
Origins
Early on in the eruption, it was found that the magma came from a depth of 14-16 km, which is almost exactly where the crust-mantle boundary is underneath Reykjanes. Crystals in the magma also showed that the magma had spend some additional time at a depth of 0.5-2 km, in the shallow dike. This was measured in the lava that was erupted during the first two days. The composition changed a bit in April, perhaps as the shallow dike became exhausted. The larger dike that was emplaced at 4-6 km depth during the rifting and shaking phase in February and March may have become the source of the magma, or it may be sourced directly from deeper down. Or both.
The bulk composition is shown in the figure earlier in the post. MgO started out at around 8.8% but increased after a few weeks to 9.6%. These values are high for Reykjanes: typical values are 7-8%. TiO2 is measured at around 1%, while for other Reykjanes lava fields it is around 1.5-2%. SiO2 has not been reported but for Reykjanes is normally around 49%. The magma clearly is not a common type for the region.
The bulk composition was last measured in June. It may not be easy to get access to fresh lava at the moment! (Note that this is NOT a call for help.)
Abundances of other elements can help in tracing the origin. These were measured in the first few days of the eruption, and to my knowledge not since. The most important result is from lead. This element has four common isotopes, which form in part from radioactive decay. That is a very slow process, but the mantle is a very slow beast. Different convection currents n the mantle can end up with material of different ages and therefore somewhat different isotope ratios. The different isotopes are chemically identical, so that the ratio of the original material that provided the melt is kept in the magma.
Lead isotopes 204, 206, 207 and 208 in Reykjanes lavas. Data from Peate, D.W., Baker, J.A., Jakobsson, S.P. et al. Historic magmatism on the Reykjanes Peninsula, Iceland: a snap-shot of melt generation at a ridge segment. Contrib Mineral Petrol 157, 359 (2009) and from http://earthice.hi.is/sites/earthice.hi.is/files/Pdf_skjol/Geldingadalir/trace_isotope_report_v1r3.pdf Black square: current eruption. Blue squares: historical lava flows in Krisuvik and Svertsangi, either side of Fargradalsfjall. Open squares: older lava flows n the peninsula. Red squares: recent submarine lava flows on the Reykjanes Ridge.
Here is the result. The lead isotopes follow the sequence of the other lavas, but with an interesting detail. The blue squares are the Krysuvik and Svartsengi lavas from 800 years ago. The cluster of open squares to the top right are other lavas from this period, the Reykjanes fires. The open squares on the bottom left are older lavas from the end of the ice age when there was a spike in activity driven by decompression melting. The top right is called ‘enriched’, for obvious reasons, and the bottom left ‘depleted’. The current eruption is less enriched than any measured lava of the previous period, but it is not as depleted as that of the post-ice-age period.
This sequence is thought to result from mixing of different magmas. How many different magmas there are is disputed, but it seems at least three are needed: the decompression melt at the ice age (long since run out), an enriched magma and a mildly depleted magma. The current eruption could be an almost pure example of the latter.
Notice the red squares? They are not on the peninsula but are from two recent lava flows (20th century) on the Reykjanes Ridge, in the Atlantic Ocean beyond Iceland. They are similar to those of Fagradalsfjall.
Lead isotopic ratio along the MAR, from Blichert-Toft et al. 2005, https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2004GC000788, with the value for the current eruption added (blue star)
This is worth exploring further. The lead isotopes have been measured below the sea along much of the north Atlantic rift – the MAR. This has shown a marked variation. While on-land a large range is seen, the MAR shows distinct regions can be seen, each with their own value. In particular, the Reykjanes Ridge shows a particular range with little scatter, with differs from that seen elsewhere. The Fagradalsfjall ratios are identical to those of the Reykjanes Ridge.
There are other elements in the lava. The rare earth elements in particular show notably low enrichment in the current eruption. On the Reykjanes Peninsula, high enrichment of rare earth elements is seen mainly in the east and the lowest level of enrichment are on the western tip. The off-shore lava is even less enriched. The current eruption is again close to the off-shore lavas.
As mentioned, recent Reykjanes magmas (i.e. the fires 800-1200 years ago) are thought to be formed by mixing two (or more) components: an enriched one and a less-enriched one. Fagradalsfjall is an example of the latter, and it seems to relate to the spreading ridge, which can cause melt at 20-50 km depth. This ridge magma would have collected at the crust-mantle boundary, 16 km deep.
There are other sources of magma in Iceland. The plume underneath Vatnajokull brings up a deeper melt, and this may spread to the peninsula. Magma pockets from previous eruptions may still be stored underneath the Reykjanes Peninsula, slowing changing composition as the magma evolves. At one time in the past there was also decompression melt, affecting shallower regions in the mantle and perhaps the upper crust. This last component is now gone: magma left behind from this will have solidified. The mixing of the other components cause the spread in lava properties on the peninsula.
Fagradalsfjall is in a funny place for an eruption. There are four volcanic centres on the Reykjanes Peninsula, but this eruption is in between two of them. There were eruptions north of here after the ice age, but Fagradalsfjall itself may not have seen an eruption since 35,000 years. The magma that had collected at the top of the mantle came up to feed the new eruption. But it did not find other magma pockets or stores: This was not a volcanic area. It gave us almost pure (primitive, as it is called, to the horror of any archeologist) mantle magma. What we see here is in effect a mid-oceanic rift eruption – on-land. It is not identical to one: the magma formed under an additional few kilometers of crust which may have provided extra weight and insulation, increasing both the temperature and the pressure. In particular, the high MgO and low TiO2 of Fagradalsfjall are not typical for the Reykjanes Ridge, or for other mid-oceanic spreading ridges. But it is close, and the lead isotopes and rare earth elements suggest the material shares its source with the MAR.
We know little about mid-oceanic-ridge eruptions. The most recent case on the Reyjanes Ridge was in 1970, at Eldeyjarbodi, 55–60 km off-shore, where lava was found to have formed on the sea floor. The eruption itself was not observed. This same region also erupted in March 1830, causing a large plume that was seen from Reykjavik. That eruption lasted with intermittent activity for a year. Perhaps it gives us an idea what to expect from Fagradalsfjall. Or perhaps not. But it is an interesting idea that we are seeing a real-life MAR eruption, the first ever tourist-friendly one. There is much to learn.
Albert, August 2021
[img]https://pbs.twimg.com/media/E86GBNCXsAENLV-?format=jpg&name=4096×4096[img]
A picture of the new island formed in Japan as well as the pumice from it’s recent eruption.
https://pbs.twimg.com/media/E86GBNCXsAENLV-?format=jpg&name=4096×4096
Can someone tell how me to include pictures here?
That worked. This finally showed me where the eruption was. Based on previous information, it seemed very close to Iwo Jima South. This puts it a little further from there
Lakigigar
You will need to get the photo posted on a website that will create a actual addressable link. I use Flicker but there are many different options. This image’s address given to it by flicker is
“https://live.staticflickr.com/65535/49380223481_3c5e1c8759_z” I left the .jpg off so it would not produce the image twice. It has to have a JPG, Or PNG……..
This is just a photo
Mac
The “parasitic” vent at Geldingadalir is splattering away. It’s building its own edifice!
I wonder how long it will last?
I’d hazard a guess that the “parasitic” vent is not much different in size to the very original vents just after 19 March. Quite a comparison!
The parasite has become top dog. It has build the biggest vent. By ‘standing on the shoulder of giants’
Is both a great comparison of how big the eruption has gotten since then, and also an idea of what is to come, this vent might take over the original at this rate, with the whole cycle of evolution we have seen since May to repeat all over 🙂
This vent already though looks more powerful than the original Bob, sustained fountain not just spattering.
It was reminiscent of Suðri for a while, getting tall with a “lava slide” down one side, but now it’s reminding me more and more of “Ragnar” when it took over from the other vents and started to get significantly bigger than any of them had previously been.
As I recall, next came the pulsing with extremely high fountains, followed by the pulsing massive overflows … will these stages be recapitulated? Wait and see. 🙂
Just back from the Fagradalsfjall route c. No good clips due to fogg but good views with a telescope. Can tell that while the big lava pond is still there, the parasitic vent has taken over as the high pressure actor making splashing fontains. The sounds are very impressive indeed!!!
Our little side vent is putting out some nice fountains.
That might change the landscape if it continues for longer – and for the worse if the lava flow is redirected towards the South…
Here is a schematic of the current situation.
😁
Yes would be cool to see the plumbing inside
well, now I see another parasitic cone starting up and heavy steaming off that north flank of the big cone. Maybe more parasitic cones are starting up? or will the whole north flank give way?
Do you remember how there was persistent smoke for days from the site where the new cone now is? Well, that’s been happening on the left hand side as well for most of the day. In fact, it looks to be getting stronger. Wild punt: ANOTHER new vent is going to open up on the left.
At 22:54 some small fountaining starts on the left. MAY just be degassing from the end of a lava tube, or maybe…
Seems to be building up, but it’s in a race against time, this eruption phase is probably nearly over.
The ‘parasitic cone’, or via Giggle Translate, the sníkjudýr keila, is certainly vigorous today.
And this makes me wonder…
If I recall aright from previous posts, the MAR runs through Geldingadalir. The intrusion runs from Keillir down to the eruption site, and the volcano erupted pretty much on the fault/MAR. We talked of the chance of the intrusion going under the MAR but this has not happened (yet). Video shots of the empty cone seem to show the conduit crack lying east to west. So the intrusion conduit is blocked by the east-west MAR line and reached the surface pretty much on the MAR. Think of an upside-down T shape.
Could the intrusion have pushed up a new conduit further to the east, along the MAR itself, presenting as our ‘parasitic cone’?
Hope that makes sense. I’ll now await for those in the know to crush my hypothesis mercilessly… 😀
The cone is really going tonight.
Gutn Tog has released another video from his new drone.
https://www.youtube.com/watch?v=KzXX04zk1sY
This man should be given an award, a medal, heck a Nobel prize!
Is it possible that another vent is emerging down the slope from the parasitic cone? mls camera starting around 22:54:00.
mbl.is camera sorry: https://www.youtube.com/watch?v=ZHZ9LU4vpf4
If it walks like a duck…
Sorry, Boogah I didn’t see your comment. I always forget to refresh.
Hi Hildur. No need to apologise in the slightest. 🙂
Looks like there is yet another new vent appearing now a little bit further to the left. It’s tiny but lively.
And getting bigger since I first watched it. And I am watching a patch on the wall which is emitting dense clouds of volcano smoke, and I wouldn’t be surprised to see another spatter cone start up there.
Starts around 22:53.
I question whether this is the primary vent location?
Note how at the end of the episode when the new vent goes dark, the main crater begins to illuminate the clouds again. The main cone is still the primary vent. The two new leaks in the side could be significant but we need to wait for the weather to clear. They are at the same level as the lava channel outflow. The small spattering cone down-stream is just the top of the build up area: it is powered by the speeding up of the flow as it goes down the slope. It is not separate vent.
It is not clear where the parasite connects tot he main flow. I think it connects to the bottom of the lava channel, in such a place that it acts as a chimney for the gas, bringing the lava with it. The lack of boiling from the main cone suggests the degassing uses the new channel. At the end it accounted for perhaps half the outflow from the main cone, with remainder going through the usual lava river. It seemed quite a vigorous episode, perhaps because the chimney allows for an easier escape route. The big cone may now be wide enough to allow for bifurcation of the conduit?
The tremor plot showed a different low-frequency behaviour. It increases slower than usual, and when it peaked it immediately started to decline again while the higher frequency tremor stayed high. I wonder whether that is because the new vent is much narrower than the main cone, so causes higher frequency noise.
It would be completely irrelevant to point out that parasitic cones normally develop towards the end of the life time of a volcano..
https://www.youtube.com/watch?v=MhHQl3BKJLE
second new vent isnt in the channel. New cone/Narlet is also a lot taller than the lava in the mai ncrater, and the fountain is high and vigorous, it has a deep source. The channel doesnt start next to it, the lava next to Narlet within the main crater is pretty still.
The second vent is not a vent. It is an opening in the outflow. We have seen such spatter locations several times. The parasite is on the side of the main outflow channel. As you know, it is not hard to raise the level higher in a narrow outlet compared to a big one, based on the same pressure, as long as the liquid is moving. It will be interesting to see how this affects the outflow channel. If it blocks it, the side of the cone might rupture.
The channel isnt fast next to Narlet, it begins behind it further to the left but in all the videos it only speeds up down the spillway some distance away. Both of these vents also erupted for nearly an hour after Nar stopped overflowing, the crater still had the lava lake and glow but the outflow channel was dark, and there was no spattering. But there was still strong fountaining from Narlet and Narlet Jr.
There was also a breakout through the wall just next to Narlet, it was a fast flow but no spatter at all.
A quick measurement indicates a slope of roughly 20 degrees at the location of the spatter. It is quite steep.
And now the MBL Natthagi cam is showing lava flowing into Natthagi again!
Thats not lava. It’s people walking back home from the eruption.
MBL’s Meradalir camera is back in operation: https://www.youtube.com/watch?v=8RV4ZhGJM5g.
@0028:51….looks like the wall to the left of the parasitic vent has breached, and it appears ‘rather’ low as well.
Game changer event?
Eruption stopped at almost the same time so we probably won’t see the result until the next cycle starts.
We really need a helicopter or drone view of the recent episode, of course there is the main new cone, which is being called ‘Narlet’ 🙂 but there is also a smaller one that is quite obviously detached, and there was spattering well behind Narlet towards the end of both this episode and the one yesterday, as though there is a new vent that is drowned beneath the lava channel, or maybe even on the north side.
To me after trying to plot it out on google earth it looks like this is actually a separate fissure line entirely, it looks very close to the main crater but the vent feeding that is on the far side, with a shallow section of lava lake before it goes into the channel, so Narlet is quite independant.
They must be connected somewhere, the activity is not completely separate, but the fact they dont stop at the same time showsthe connection is not a surface level feature, might even be a km deep or more. The ground is going to be very hot there so perhaps that is why there was no seismic activity forming this new dike.
https://www.youtube.com/watch?v=MhHQl3BKJLE
I think it is pretty undeniable now, new vents for sure and they are not aligned with the fissure from March-April, parallel a few hundred meters east.
There’s no gas plume coming from the lower spattering, so it has likely been degassed already. Probably a lava tube skylight.
Maybe, but I cant recall there being a tube here and the spattering is really high sometimes, tens of meters. Tubes breaking out usually make dome fountains not high spattering.
It also only lasted around 2 hours so maybe just didnt get started properly, there was not much lava flowing out of it at any time. Tomorrow will be interesting for sure.
At 22.54 on the MBL Close-up camera what could be a new vent begins spattering about 2/3 of the way down the slope from the parasite vent; which has grown its own significant cone. Then at 00:28 two holes are punched through the wall of the main cone with significant flows for about half an hour before activity in the cone stops for the current cycle.
Oops – old news. Should have refreshed before posing.
Monday
16.08.2021 22:49:28 64.062 -21.405 3.7 km 3.1 99.0 2.8 km N of Hellisheiðarvirkjun
If (I’ll use that word for now) these are new vents on a parallel fissure further east, how does that align with the cracks that were seen on Theatre Hill recently? It could mean those are expansion cracks due to increasing pressure underground. However, as they would be on the south side of the MAR fault, they will be limited to only expansion, as no lava reaches that far south.
They line up but not directly, parallel with the cracks and also with the original fissure line. I dont know it is so impossible for vents to cross the fault, just because it didnt happen originally doesnt mean it is a hard rule, fissures in other systems do with little resistance it seems. Might even be a coincidence the eruptions have all been north of the fault.
I think the main reason why it is hard for the intrusion to cross the MAR fault is that whatever crustal weakness the intrusion has exploited on its way up, simply isn’t there on the other side of the MAR. The crustal movement has moved that line of weakness off to the side, and the rock that abuts the intrusion is a lot stronger.
That said, it could cross if it happens to find a line of weakness that more or less lines up on either side.
Ready to be proven wrong, of course, as tends to happen often when willful volcanoes are involved 🙂
I noticed the drumplot for faf fra picked up something at 22:50:00 which was just a few minutes before the 2nd ‘disturbance in the lava’ started a bit further down from the parasitic vent.
https://ibb.co/VjjTzZ3
It’s so annoying to visit this site. There are hardly any volcano discussion forums, and i wanted to see on what some people had to say on that Japanese submarine volcano, and all you can find are hundreds of Icelandic posts. It’s so annoying…
We are a small team running this in our spare time. I am sorry if you find us annoying.
RE:”We are a small team running this in our spare time. I am sorry if you find us annoying.”
“Holy, ‘you can’t please all of the people all of the time’, Batman!!”
I don’t think you’re annoying. It’s just i wish there was more structure in these discussion posts and a bit more coverage (if not in a general post, just here in the comment section) about the submarine volcano, although there is in general a lack of information, except for twitter posts that are repeated a 1000 times.
Really gives you an idea of how developed volcanology as a science is… . The only thing i know is that we in general – as amateurs or scientists – don’t know anything about it, less than almost any other exact science subject imo, and yes that frustrates me.
There were some posts on the previous page of comments about the Japanese volcano.
There are more camera’s and updates available for Iceland, hence it getting more attention
https://watchers.news/2021/08/16/new-island-major-submarine-volcano-fukutoku-okanoba-japan-august-2021/
https://www.volcanodiscovery.com/fukutoku_okanoba/news/138672/Fukutoku-Okanoba-volcano-Japan-satellite-image-of-pumice-swirling-in-the-Pacific.html
A post on the Japanese volcano would be interesting, since it seems to be a fairly large eruption. You could use it to discuss the process which barely underwater volcanic eruptions follow. Apparently the new island is 1 km, though it looks like it should erode away quickly
There have been several islands here from previous eruptions. They tend to last a month or so.
If a topic is not covered, then write about it!
VC is a friendly place and no-one trashed my rather badly written articles. 🙂
Writing an article is a great learning experience and diversifies the subjects we can talk about.
That would take rather more free time than I have at the moment. Plenty of class-related writing in my immediate future!
What do you guys make of this?
There seems to be a whisp of SO2, coming out of Michael (Sandwich Islands Volcano).
https://www.windy.com/-Show—add-more-layers/overlays?tcso2,-59.210,-26.587,6
It looks like it has a history, so well worth watching!
https://volcano.si.edu/volcano.cfm?vn=390090
RE: “https://volcano.si.edu/volcano.cfm?vn=390090”
Thanks for this. I’ve bookmarked the link to the home page.
https://www.icelandreview.com/news/reykjanes-eruption-giant-gas-bubbles-linked-to-fluctuating-activity/
Eruption temperatures of 1240 C been confirmed! For fagradalshraun thats as hot as Kilaūeas summit lava lakes! ( But Kilaūea is much much hotter at depth )
Fagradalshraun coud last decades the geologists belives. Now its an open pathway pipe. With crust tank that empty during 12 hours of eruptions and refills during nearly a days sleep
The eruptions are growing longer and volume is Increasing.. very predicatable. Its making itself a lava shield. Becomming a Mauna Ulu perhaps
It simply wont stop at all .. the supply keeps comming. So it coud .. last decades
This is becomming a major game changer for icelandic tourism. The lava have not yet reached the Atlantic ocean as its keept inside the fagradals Mountains near Grindavik.
Its quite odd that this activity have not yet happened inside the huge high supply central volcanoes in Iceland. But Grimsvötn have developed a gigantic Sulfur output since march 2020 ( perhaps a Halema’uma’u style lava lake is in making there too )
I thought of Mauna Ulu, too. Both Ulu and O’o developed wandering satellites off the initial fissure, too.
Well, “could last decades the geologists believes” is not what I read in the article. It says, what we all believe anyway, namely that “Experts have stated there is no way of knowing how long the eruption will last: it could end at any moment or continue for years or decades.”
Looked at the satellite pic in this excellent post and then the latest 3D update. Something very Slake Moth about it.
New post is up! Escape from Fagradalsfjall?
https://www.volcanocafe.org/escape/
The volcano seemed to be ramping up to another episode, according to the tremor graph, when the YouTube video just quit on me! It acted like it had reached the end of a non-live video for some reason, and I can’t get it working again. Seeking doesn’t work, etc.
How do I fix this? Hurry, there could be lava visible any minute now if the tremor graph is to be believed.
And [i]why[/i] am I constantly besieged by problems with bloody YouTube? I’ve got a bog-standard browser and OS. Nothing peculiar here that could be raising compatibility issues.