Kilauea Erupts, La Palma Eruption Intensifies, Fagradalsfjall Quakes Raise Questions

 HAWAII, USA - Kilauea began a new eruption after weeks and months of inflationary tilt and occasional quake swarms. As of 3:20PM HST, USGS posted the following update:

"Kīlauea volcano is erupting. At approximately 3:20 p.m. HST on September 29, 2021, the USGS Hawaiian Volcano Observatory (HVO) detected glow in Kīlauea summit webcam images indicating that an eruption has commenced within Halemaʻumaʻu crater in Kīlauea’s summit caldera, within Hawai‘i Volcanoes National Park. Webcam imagery shows fissures at the base of Halemaʻumaʻu crater generating lava flows on the surface of the lava lake that was active until May 2021. 

The US Geological Survey Hawaiian Volcano Observatory (HVO) is elevating Kīlauea’s volcano alert level to from WATCH to WARNING and its aviation color code from ORANGE to RED as this new eruption and associated hazards are evaluated.   The activity is confined to Halemaʻumaʻu and the hazards will be reassessed as the eruption progresses. 

USGS volcano alert levels and aviation color codes are explained here: https://www.usgs.gov/natural-hazards/volcano-hazards/about-alert-levels 

The opening phases of eruptions are dynamic and uncertain. HVO continues to monitor the volcano closely and will report any significant changes in future notices. Stay informed about Kīlauea by following volcano updates and tracking current monitoring data on the HVO web page (https://www.usgs.gov/volcanoes/kilauea/volcano-updates) or by signing up to receive updates by email at this site: https://volcanoes.usgs.gov/vns2/. 

HVO is in constant communication with Hawai‘i Volcanoes National Park as this situation evolves. The eruption is currently taking place entirely within the closed area of Hawai‘i Volcanoes National Park. 

Hazard Analysis: This new eruption at Kīlauea’s summit is occurring within a closed area of Hawai'i Volcanoes National Park. Therefore, high levels of volcanic gas are the primary hazard of concern, as this hazard can have far-reaching effects down-wind. Large amounts of volcanic gas—primarily water vapor (H2O), carbon dioxide (CO2), and sulfur dioxide (SO2)—are continuously released during eruptions of Kīlauea Volcano. As SO2 is released from the summit, it will react in the atmosphere to create the visible haze known as vog (volcanic smog) that has been observed downwind of Kīlauea. Vog creates the potential for airborne health hazards to residents and visitors, damages agricultural crops and other plants, and affects livestock. For more information on gas hazards at the summit of Kīlauea, please see: https://pubs.er.usgs.gov/publication/fs20173017.
Vog information can be found at https://vog.ivhhn.org/. 

Additional hazards include Pele's hair and other lightweight volcanic glass fragments from the lava fountains that will fall downwind of the fissure vents and dust the ground within a few hundred meters (yards) of the vent (s). Strong winds may waft lighter particles to greater distances. Residents should minimize exposure to these volcanic particles, which can cause skin and eye irritation. 

Other significant hazards also remain around Kīlauea caldera from Halemaʻumaʻu crater wall instability, ground cracking, and rockfalls that can be enhanced by earthquakes within the area closed to the public. This underscores the extremely hazardous nature of Kīlauea caldera rim surrounding Halemaʻumaʻu crater, an area that has been closed to the public since late 2007."

The eruption is occurring within the summit lava lake which was recently formed in December 2020, when a small fissure poured into the water lake which had accumulated after the caldera forming collapse of 2018.  

The lava appears to have had no trouble in breaking through the still-cooling lava lake to 'reactivate' it, and is currently filling the caldera with newly erupted lava. This appears at this time to be a different fissure, perhaps related to a magma intrusion that occurred several weeks earlier.

From HVO, current thermal image of the Halemaʻumaʻu caldera with the new lava fountains.

Halema'uma'u erupting new lava into the May 2018 caldera, post 202 Dec eruption. 

Summit webcams can be found here: Webcams (usgs.gov)

LA PALMA, CANARY ISLANDS, SPAIN - The eruption of La Palma's Cumbre De La Vieja which began after months of low level quake activity continues with vigor, and as of yesterday, the lava flow is now entering the Atlantic Ocean. The events began with a bang, as on the central West slope of Cumbre De La Vieja (literally 'Old Summit' - which is a misnomer as this is the younger of two coalescing stratovolcanoes on the island), as a new pyroclastic cone has been constructed along several small fissures.

The unfortunate placement of this eruptive vent has destroyed hundreds of homes, cut across main highways and roads, and completely disrupted travel to and from the island. The government has promised swift and unimpeded aid to those displaced by the eruption. 

You can view a live feed of this powerful eruption here.

Live 24/7 coverage (in Spanish) can be seen here.

The last eruption on La Palma occurred some 50 years ago, at the Southern tip of the island, and lasted for several months. While it is too early to tell how long the current eruption may endure for, it could be assumed to be similar in duration.

REYJANES PENINSULA, ICELAND - The eruption at Mount Fagradals has gone into a quiet phase for about 10 days now, the longest pause since its 9 day hiatus weeks earlier. During this 'quiet' phase, tremor pulses have been erratic but weak. However for the past few days, a quake swarm has been rattling the region with small, but numerous temblors.

From IMO, the tremor at Fagradalsfjall is picking up. 

 

This has been interpreted in two ways: 1) It could be the 'death throes' of the eruption, signifying small internal collapses within the magma channel, and the readjustment of the crust surrounding it while it 'relaxes', or 2) It could mean that magma supply to the main vent at Fagradalsfjall has been cut off and the magma is trying to find a new pathway to the surface, presumably closer to Mt. Keilir, which was originally assumed to be a possible eruptive center.

Elsewhere in Iceland, the Askja (Ashes) volcano is displaying an abnormally high rate of earthquakes with accompanying deformation. The land has risen over 15cm within the last month, and shows no signs of slowing down. Icelandic geologists are installing more equipment to better monitor this very dangerous volcano, however they have been hampered by poor weather conditions in addition to its remote location.

And that's not all from Iceland... Several other volcanoes are beginning to show some warning signs including Katla, Hekla, Bardarbunga, and Grimsvötn. Grimsvötn's Vatnajökull glacier recently had a massive jökullhlaup (glacier outburst flood) which sustained for weeks, which has raised some concerns that the volcanoes of Vatnajökull are preparing for eruptions.

Quakes at Hekla, which are uncommon but can preceded eruptions, have been ongoing for quite a while, and scientists say that it is more pressurized than it was during its last large eruption. 

And surprisingly, there is even some geological action out in the Snaefellsnes Peninsula, where the volcanic system of Ljosufjoll is displaying seismic activity as well. The last eruption in this region was some 1000 years ago. 

Eruption at Fagradalsfjall Continues After Lull

 In Iceland, on the Reykjanes peninsula, the eruption at Fagradalsfjall entered into a 9 day dormancy, which caused some to speculate that the eruption may be ending. This was proven false several days ago, when rock fracture volcanic quakes, and a gradual increase in tremor resulted in a new phase in the eruption. Currently the volcano is 'pulsing' with activity that ranges from 10-15 minutes of lava effusion, and about another 15-20 minutes of quiet. This pattern has continued for several days now.

Today, a large lava breakout near the main erupting crater created a cascade of lava down into Natthagi valley (translated to 'Nigeria Valley' with online translation). 

The current view from Nigeria Valley. Courtesy of mbl.is.

Earlier, cameras trained on the volcanic crater also captured an individual scaling, then walking along the crater rim of the main vent, which was, to say the least, extremely foolish and a poor example for others. Icelandic authorities have had to repeatedly warn people not to tread on recently cooled magma both in Nigeria valley, but at Geldingadalur valley. 

Months earlier, one man, who later identified himself on social media, was spotted near the main crater narrowly escaping a sudden lava gush.

People should be reminded this volcano is unpredictable, and has shown to be hazardous in many ways. Gases that may seem to be blowing away from you could swiftly shift direction. Lapilli in the air can cause lung irritation. Lava breakouts, and new fissures are still possible. The very ground could open without warning, and issue hot gases and lava. Volcanoes are not toys, and they're not good for the 'Gram if you're dead.

End PSA.

Tremor plots currently show a high level of activity, and it is unknown whether the tremor plots currently being displayed are the result of a computer glitch, or if they are truly what is occuring. 

Krisuvik graph showing massive tremor range to the right. From Iceland Met Office. 

Fagradalsfjall graph showing more intense 2-4hz frequency amplitude.

As both graphs show similar data, it is probably not a data artifact, rather, the volcano is entering a phase of more fierce degassing after being 'clogged' essentially for over a week. Think of it a bit like putting your thumb on a hose filled with carbonated water. If you hold the hose upright, a gas chamber builds, and when released, the gas emission increases (which did happen), and then you get the mostly degassed liquid spouting out first, then the gassier liquid rises faster.

I expect this activity will continue until returning to the phase that was going on previously, with long, intense periods of lava effusion followed by long, quiet spells. But as many Icelandic scientists note, this is not a predictable eruption, and may be the first of its kind to be recorded in Iceland.

The magma source isn't coming from a magma chamber, rather it is coming from the mantle with a clear shot to the surface. Over time, the volcano may end up constructing its own main magma chamber. The past week's activity suggests some smaller ones may already be forming under the newly erupted lava, evidenced by today's outburst of lava from under the crust of the Geldingadalur lavas. 

Some scientists have speculated that even when activity in the main crater is not evident, magma is still gathering under the solidified lava.

In any case, the eruption continues to surprise scientists, delight tourists, and as far as eruptions go, this one has been mostly beneficial to Iceland. 

But please, for all that is sane and good in this world - DO NOT STEP ON THE LAVA.

Why The Eruption At Fagradalsfjall Is Unprecedented

 The eruption that began in Iceland's Reykjanes peninsula in March of 2021 has for the most part shocked scientists, volcano enthusiasts, and tourists alike. The volcano, it seemed at the time, was (or still is, depending on who you ask) part of the Krýsuvík-Trölladyngja system, which was experiencing its first magmatic eruption in some 800 years. The conventional wisdom at the time was that this was a relatively small eruption that would probably only last a few weeks. This has been proven wrong, the question now is why?

One need not look much farther than Iceland itself. Icelandia is a submerged continent who's geological history is incredibly complex. Until recently, Iceland was thought to be a volcanic hotspot underneath an oceanic spreading ridge. It turns out, that not only is Icelandia a continent, it may have existed since before the ridge, been submerged, only to split and have a hotspot form under it in the last several million years. 

This is significant, since original, ancient continental crust would provide more protection/insulation from magmatic intrusion, but since the continent of Icelandia drifted into (or was split in two by) an oceanic rift, the geology is unique. On one hand you have very thick crustal regions, and in the split middle, you have a thin layer of hardened material before you reach a mantle source, in some areas.

This explains in part the presence of stratovolcanoes on Iceland, as typically a stratovolcano is constructed by means of recycled or at least conglomerate material - mantle sourced, primitive magmas, mixing with more advanced, modern crustal material, which incorporates both H2O and organic components leading to explosive, tephra generating eruptions.

 Without any crustal 'recycling', you'd expect the entirety of Iceland, or at least most of it, to display mostly Hawaiian-style hotspot eruptions much like the current eruption at Geldingadalur. 

Back to Iceland's newest eruption, it has not gone according to conventional science, however there is precedent. 

A few days ago, Fagradalsfjall volcano had a brief period where ash was emitted, in what was thought at the time to be the end of the eruption. A similar event occurred at Kilauea, on the big island of Hawaii, at Pu'u'O'o crater. Magma had drained down rift, rapidly draining the small magma chamber under the spatter cone of Pu'u'O'o, and quickly, the roof of the chamber caved in, generating a rather interesting plume of ash, gas, and vapor. While magma has not yet returned to Pu'u'O'o, it can be reasonably assumed that it may, given the right circumstances.

Fagradalsfjall, however, is brand new! This is a magma dyke that has come from quite a depth, far deeper than any extant magma chamber in Iceland. It is not a magma chamber, rather it is a crack that goes down far enough to a mantle source, to build a magma chamber ABOVE land. It is building a new shield volcano. A Shield volcano forms layer-by-layer. The most famous example of which is probably Mauna Loa, the largest active volcano by volume in the world, on the big island of Hawaii.

Mauna Loa likely started life out just as Fagradalsfjall, as a minor crack in the ground, slowly growing and expanding, issuing fluid lavas, until a massive, shield-shaped mountain formed. Over millions of years, volcanoes like Mauna Loa grow their profile, building their own reservoirs of magma, and over time, building their own magmatic plumbing systems. The older they get, the less likely magma injections lead to eruptions (at least for most non-hotspot shields). 

Hotspot shield volcanoes, like Mauna Loa, however, can grow to immense proportions, and last for millions of years. While it is highly unlikely that the new volcano at Fagradalsfjall will be as dynastic as Mauna Loa, it is far, far too soon to tell.

What is clear, and what I will predict is that Fagradalsfjall (or whatever the official name for it will be in the future) is likely to be a very long eruption, with minor pauses, sometimes even months, in between. But this volcano is likely here to stay, providing Iceland with a bit of tourism excitement, but also questions in regards to how ti handles the eruption and disruption to infrastructure.

Already, Iceland has fought this volcano. It has constructed several dirt and rock berms by which to redirect the lava flows away from roads, homes and infrastructure. While the first two berms constructed did fail, several others appear to have learned from the previous berms, and have held. One is preventing the lava from spilling into a valley to the SW of the main vent, while the other is preventing lava from advancing towards the South Road highway, and several farm houses. 

Whether this is going to work or not is unclear, but one thing is certainly notable - Iceland is the only country that I am aware of to successfully fight and redirect lava flows when they threated critical infrastructure. This is quite an impressive feat, and civil engineers should take note. 

Today's activity at Fagrdalsfjall seems to consist mostly of lava-lake activity within the main vent, with some occasional overflows and large strombolian explosions. A new pattern has emerged in the past several days, from an easy-effusiveness to violent lava lake activity, followed by periods of outflow, then massive overflows. This is then typically followed by a period of perceived inactivity (although we cannot tell what is going on under the crater, it is assumed that 70% of the eruption and effusion is occurring out of view in underground lava tubes). 

The resumption of activity is typically begun by gas emissions, followed by the gradual appearance of lava fountaining, and eventual resumption of overflows. The time is not consistent between events, so it is unclear whether this is just a random 'sputter' or if the volcano is building up to something else, or building to an end. I suspect this will keep going on for several years, if not decades. But only time will tell. 

Second Fissure Opens Up At Fagradalsfjall (UPDATE - THIRD FISSURE ERUPTS)

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 flow from the new fissure is beginning to pool on lava issued by fissure 1 (Bob). 

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.

Hraunbreiðurnar ná nú saman (mbl.is)

*****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. 

ERUPTION In Iceland! Fagradalsfjall ERUPTS

 About 1 hour ago, Mount Fagradalsfjall erupted. Some webcams are able to see the eruption including this one. Color video (not the best shot) can be seen here. A camera from RUV.is is here. 

Location of the new fissure from MBL.is

A massive glow can be seen above the mountain, in the area that was predicted to be the most likely spot for an eruption to occur. 

Fissure vent is feeding pahoehoe lava flows.

Screengrab from the IPCAMLIVE 

Image from Icelandic Coast Guard chopper aerial flight. 

A helicopter is apparently flying around as can be currently seen in webcam video.

While it is nighttime, it is impossible to see how high the lava fountaining is at the moment.

The Iceland MET Office has confirmed the eruption.

As stated in a previous post, it is not uncommon for quakes to stop, or slow once an eruption is imminent, and that was the case here. Seismicity dropped to lower levels with very few large quakes. Some scientists believed that an eruption would not occur. Others are theorizing that this may be a new phase for the entire peninsula. Seismicity is still quite low, even with lava now escaping to the surface.

Current seismicity remains lower than the last several weeks.

It is not known how long this eruption may last for, or where the new lava flow models predict that lava will go. We will likely know more once the sun rises in Iceland and more coverage begins. 

There are a few possibilities:

- The eruption is short-lived, lasting only hours to days

- The eruption gains a steady, deep supply of magma and erupts for weeks, months, or years

- The eruption occurs in phases, in fits and starts, until ceasing altogether

As magma is theorized to still be coming into the dyke system, this eruption will likely at least last for a week or two, although it is anyone's guess at this point.

Currently, the magma appears to be fast-flowing pahoehoe style lava, similar to Hawaiian eruptions. Lava this fluid may travel fast.

I will update this post separately from my previous post on the quake swarm, as an eruption is now underway, however if you'd like to refer to the lead-up to the eruption, you can see my previous coverage here. 

*****UPDATE 3/21/2020*****

The eruption at Fagradalsfjall continues. It is as expected, a low-threat eruption with little to no ash emissions. Iceland has cancelled the aviation warning. Many people are showing up to the sit to view the eruption up close. While the eruption may seem safe, this is not advised. New cracks, fissures, or vents can open at any time, as was the case in the Leilani Estates fissure eruption on the Big Island of Hawaii. People should avoid the area, and only take helicopter tours if possible. Of course, you cannot completely deter thrill-seekers, and this would be difficult to control around the clock.

The lava cone that has become the main vent collapsed earlier, spilling out a large pahoehoe flow which is advancing off-camera at ruv.is. It is unknown at this time whether this means the lava flow has found a new outlet and will drain further out of the main area. As lava flows cover the initial zone, it will create ledges, and lava will find a way to its lowest point. If the lava flows continue for weeks or months, it will likely flow to the lowest area it can find. 

This part of the eruption is expected to last from days to weeks, but probably not much longer unless another large injection of magma feeds into the current system. Flow rates fluctuate slightly, but overall the eruption appear consistent in its flow rate. 

Minor Strombolian and major pahoehoe effusive activity is occurring at the moment, with little to no change since the onset of eruption, although the number of active vents has now been reduced to around three or four. 

The fact that pahoehoe is the main product of this eruption strongly suggests a mantle source, as this would not be 'old' magma erupting as lava, however that is yet to be determined by volcanologists. Lava samples are needed to determine crystallization, gas, and other metrics to show whether this is older lava that has been forced up by newer magma, or if this is a mantle sourced 'new' channel. 

*****UPDATE 3/22/2021*****

The eruption continues at Fagrdalsfjall. The new eruptive center has been named for the Geldingadaulur valley, which roughly translates into 'Castration Valley' in English. While the eruption has occurred in Fagradalsfjall Pleistocene volcano, some sources theorize that the eruptive fissure is sourced from the more recent Krysuvik-Trolladyngja volcanic system, some miles to the East. However this is yet to be determined, as no chemical analysis is yet available, and data is still coming in.

What we do know at this point, is that base don historical data, activity in Reykjanes peninsula seems to come in long phases, followed by long periods of rest. It seems that the last period of rest is over. Some volcanologists and bloggers suggest that this could be the start of a new 'volcanic dynasty' in Reykjanes, or that eruptions should take place nearly every year for the next several hundred years. 

I do not share that assessment, although it is too early to tell. In my own opinion, volcanism from this vent will continue for several weeks, to perhaps more than a month, followed by a period of quiet, perhaps more than several years, before another monogenetic event breaks out. This might continue for a couple of decades or so, with rare, but predictable events occurring down the peninsula. However there is no concrete evidence at this time that points to a prolonged volcanic period on the peninsula.

I of course could be flat wrong here, however I don't think that current events indicate a 'major' change in activity, but perhaps a rare avenue for a minor magma surge to emerge and create a spectacle. 

This of course could change if major activity resumes after the eruption halts, or if a major tectonic event opens up wider avenues for magma to flow up to the surface. In any case, the current spectacle is simply amazing, and fun to watch. It is fortunate this eruption has not impacted any communities, and provided a bit of excitement for locals and media during what is probably the worst last couple years in human memory with the misery of COVID-19. 

You can watch the eruption on YouTubelive from RUV.is below.

*****UPDATE 3/23/2021*****

A mantle source for the lava currently being erupted in Geldingadaulur has been confirmed, which completely changes the calculus for Iceland regarding the eruption. Fluid lava is issuing at a steady, if not increased pace at the current vent area, which now consists of a ~400 meter high lava cone (prone to frequent collapses yesterday), with an insulated lava vent on its side. A second vent opened up (to the left on the above camera) which is vigorously issuing lava at around the same rate as the 'main' vent. 

It is now being theorized that due to the steady effusion, and fluidity of the magma, that this comes from a mantle source some 40-km deep (or deeper), and that this magma freshly broke through the crust, and could be a distinct magmatic system from nearby volcanoes like the Krysuvik-Trolladyngja system. 

If this is true, Iceland could be in for a very long eruptive period with a shield-building event not unlike the long eruptions in Hawaii. When magma finds a steady channel to the surface, there is not a lot that will stop it from continuously flowing to the surface. The only things that could stop the eruption would be that magma injection slows to the point it can no longer erupt, and the dyke that was feeding the lava to the surface cools. This does not appear to be a likely outcome any time soon. If anything the rate of flow has increased since the onset of the eruption.

The other option is that this is a long-lived monogenetic event that persists for years, not unlike the Paricutin eruption in Mexico.

Gas in the area is now extremely hazardous as the winds have died down somewhat, and the lava field grows. Icelandic authorities are having to station police and emergency personnel near the eruption site to keep people from getting lost, or putting themselves in danger to see the volcano. It is advised that if you want to watch the eruption, simply stream it rather than putting yourself at risk.  

New satellite imagery of the eruption site was also released by MBL.is today (image below)

NASA image of the eruption site.

*****UPDATE 3/24/2021*****

The eruption at Fagradalsfjall/Geldingadaulur continues. Effusive eruption continues at a steady rate, with no signs of weakening as of yet. Pulses of extremely vigorous emission have been observed. There have been several instances of lava tubes forming on the flanks of the main cone, which is now joined to a more vigorous, elongated vent which is just as active as the former main vent, if not more so.

The lava is pooling in an area with no outlet at the moment, so over time, lava channels will probably redirect the the lowest point on a perched table, which may speed up lava advances to lower valleys like the originally speculated eruption location of "The Night Pasture", or Nátthagi valley (Icelandic translation is not perfect here). If lave begins to enter this valley, it would likely become a main exit for new flows, but that of course could change if vent structure does. 

For now, the lava is pooling in a relatively safe area, with no threat to infrastructure or residents. It could probably not have erupted in a more convenient area, which is quite fortunate for the town of Grindavik, which is the nearest to the eruption site. 

*****UPDATE 4/1/2021*****

The eruption continues, with no sign of slowing down in terms of lava output. Tremor remains variable, and several quakes of up to magnitude 2.9 have occurred in the last several days. No news yet on whether deformation changes indicate any change in the rate of eruption, or any indication of whether or not this will continue for a long time.

Geldingadaulur vally is nearly filled with lava. A recent article by MBL.IS has posted the below photo of the current amount of lava filling the valley as seen on 3/31/2021. 

Photo from RUV.IS showing the extent of the lava in Geldingadaulur valley.

The eruption will likely continue until the magma pressure is cut off, and the surrounding cooler rock solidifies the magma dyke. If the eruption continues, with mantle driven magma, there is every chance that the dyke will erode and melt its boundaries, becoming wider. If this indeed mantle driven magma from a deep source, this could indeed create a larger magma channel over time, if the pressure persists.

If a new, large magma channel is formed, this can create a shield volcano over time. Although it is too early to tell, some have speculated that this is the birth of a shield style eruption.

However, it should be noted that a similar eruption in Mexico of the Paricutin volcano, was similar in many ways. This could be a 'monogenetic' event where a new lava/spatter/cinder cone/lava dome is formed, and never erupts again. 

The Reykjanes Peninsula is riddled with monogenetic cones with large lava flows. It stands to reason that this eruption might not be much different. But with volcanoes, and mantle-driven sources, the proof is only in the results, as we cannot truly see deep enough to know what to expect. This could end up being a very long eruption, the tip of something bigger, or a small eruption that entertained Iceland and petered out after several months or years. 

Hopefully, in the coming weeks and months, more and more data metrics will give a clearer picture of the mechanics of this eruption, and enhance volcano science for the better. It has been a long time since humans have witnessed a 'new' volcano being born, even if all of Iceland is in fact volcanic in origin. This remains an exciting event.