Friday, November 18, 2016

Bardarbunga Returns

Bardarbunga Volcano has just now initiated a series of larger-than-normal background activity quakes which could indicate a new eruption is not far away. In Bardarbunga's caldera, SW from the Holuhraun eruption of 2014-2015, a quake swarm with the maximum magnitude of 4.0, followed by several smaller quakes, and than several 3.0-3.4 quakes hit within the last hour.

What this means is not certain, but it is a part of a pattern of magma movement, that much is clear. Iceland is undergoing a period of active rifting. This rifting enabled Bardarbunga's lava flow at Holuhuraun by making it easy for up-welling magma to find weaknesses in the crust to penetrate and form a dyke intrusion. This eventually gained enough pressure to burst through the crust and create a massive lava field.

The current activity can be seen below:


Current image from Iceland Met Office showing vigorous quake swarm at Bardarbunga Caldera.

The last time Bardarbunga erupted, it was an effusive, not explosive eruption. It was characterised by a fissure opening in the earth, with lava pouring out at a vigorous rate. This was the largest lava-field creating eruption since the devastating Laki fissure swarm in the 1700's. The eruption lasted for months, and created a vast lava field that reached to the boundaries of the Askja volcanic system, which may could also be getting pressurized by the rifting of Iceland. Seismicity in that area has been at a steady level for quite some time now, and it is anyone's guess when it can erupt. 

If, however, Bardarbunga chooses to erupt from it's caldera, this could pose a very large threat to air traffic, local farms and livestock, and create a fair amount of havoc. Eyjafjallajökull's eruption in 2010 was small compared to some of its neighbors like Hekla, Katla, and Baardarbunga. Even the eruption of Grimsvötn (Grimsnes) in 2011 would be much smaller compared to Bardarbunga. It has a much larger caldera, and has proven to have been able to produce very large, up to VEI 6 (Feb. 1477) eruptions.

The main threats from Bardarbunga are large scale plinian eruptions (from the caldera), coupled with lava interacting with ice (which produces pulverized ash, which is quite fine and carries very well on wind currents), and the sheer scale of the magma we're talking about. It's currently, not a small amount. Plainly, it probably won't be much fun for anyone within its reach. And definitely not for aircraft. 

At current I do not believe an eruption to be imminent, but as with all Icelandic volcanoes, sometimes they don't give much warning, so it is worth keeping an eye on tonight. 




Friday, September 30, 2016

Katla Volcano In Iceland Alert Raised [UPDATED 10/16/16]

Katla volcano in Iceland has been raised to Yellow status, as a near three day quake swarm is rattling the massive volcano. A warning from Icelandic authorities has been issued as follows (translated):

"The National Commissioner of Police and the District Commissioner of Police in South Iceland have declared a Civil Protection Uncertainty phase due to seismic unrest in Katla volcano in Mýrdalsjökull.

The contingency plan for an eruption in Mýrdalsjökull has been activated accordingly. Uncertainty phase means that a course of events has started that may lead to natural hazard in the near future. Monitoring, assessment, research and evaluation of the situation is increased.

Increased seismic activity started on September 29 and is still ongoing. Following a meeting with the Scientific Advisory Board of the Icelandic Civil Protection it is likely that the seismic activity is caused by magma movement within the Katla caldera. Three most likely scenarios have been defined.

1. Seismic activity dies out with no further consequences
2. Glacial outburst flood, jökulhlaup, will emerge from the glacier due to a small eruption
3. Eruption starts in Katla Myrdalsjökull that will force its way through the ice with glacial outburst floods and ash fall Accordingly a warning has been issued for travelers in the vicinity of Mýrdalsjökull especially around glacial rivers."

Katla volcano has not erupted since 1918, according to the Smithsonian GVP. It's smaller neighbor, Eyjafjallajökull erupted in 2010, with an eruption of Grimsvötn (Grimsfjall) following the next year.

In the past few days, there have been hundreds of quakes within the caldera under the glacier Myrdalsjökull. This follows the events of August when two earthquakes of mag 4.5 were detected in the caldera. Many of the quakes in the current swarm are 3.0-3.5 in range.

Screenshot from Icelandic Met Office Website

It has been theorized for many years that Katla was 'overdue' to erupt, given that it is typical for Eyja to trigger Katla, or vice versa due to a theory that says the two magma chambers may share a sill that allows their magma chambers to interact.

According to some, Katla may have long been 'primed' for eruption and was awaiting some seismic activity to trigger it, much like Japan's Mt Fuji is theorized to be. It is still of course possible that this earthquake swarm does not end up in an eruption, or has a small sub-glacial eruption, but time will tell. This is a vigorous and apparently escalating swarm. It is a great time to keep an eye on it. There is a good webcam here.

*****UPDATE 10/6/2016*****
After a few days of absolute quiet at Katla following last week's vigorous swarm, a new swarm has begun at Katla in much the same location within it's glacier-covered caldera that last weeks swarm occurred in. So far today, three quakes above mag 3.0 have occurred. Weather interference is preventing some of the equipment from tracking the smaller <1.0 mag quakes, however this should clear up for a short window of seismic recording by sometime tonight. 

This does now appear to be volcanically, not tectonically, related. At the time of this writing, this is the current snapshot of the swarm from Icelandic Meteorological Office:

Screenshot from Icelandic Met Office Website

The quakes have so far not resulted in any eruptive activity, although prior to this week, elevated conductivity and gas levels were detected in one of its river outlets. This typically can indicate magmatic activity. Further, some quakes do now show the telltale sign of magma movement. 

It is still possible that the quakes will not result in an eruption. Some 80% of magmatic activity and dike intrusion does not immediately result in an eruption. But Katla has been silent for many years, so this activity does not lessen the chance of one. 

Meanwhile to Katla's NE, Bardarbunga is again experiencing some heavier seismicity. It is suspected that the fissure eruption to the ENE of it's caldera at Holuhraun could have been a prelude of a much larger event years later.

Other volcanoes showing a bit of life in Iceland include Hekla, which has had several minor quakes this year (it does not typically give warning before an eruption, so quakes are concerning), and Askja volcano to the North of the Vatnajökull ice glacier (which covers Bardarbunga, and Grimsvötn, among other large volcanoes). Askja has been showing increased seismic activity since the dike intrusion and fissure eruption of Bardarbunga. It's last eruption in the early 1900's was one of Iceland's largest since the eruption of the fissure swarm Laki. 

Long story short, Iceland is primed to be a hotspot of eruptive activity in the near future, and will no doubt cause more travel chaos in Europe and perhaps the Northern Hemisphere.

*****UPDATE 10/16/2016*****

Another quake sequence has begun in the last couple hours at Katla volcano. The pulses are now forming somewhat of a pattern, although that probably means nothing. In these 'pulses' of activity, after the larger sequences, the quakes don't seem to go above mag 2.5.

The current quake sequence is more than likely due to magma intrusion. Elevated seismicity within the caldera has now become so persistent, it would be a good bet that an eruption is on it's way in weeks or months. 


Screenshot from Icelandic Met Office Website

The current activity has resulted in higher gas and conductivity levels within glacial runoff streams. Recent weather diluted the streams with rainfall, and interrupted measurements, but newer ones confirm something is going on under Myrdalsjökull. It is only a matter of time in my opinion.

Friday, September 2, 2016

I Live in Hawaii Now!

As it happens, becoming obsessed with volcanology as a hobby can drive you to do things you may not have thought you could do. My wife and I successfully, and smoothly, moved to Oahu, Hawaii last month, and for a volcanophile, this is heaven. The Hawaiian island chain is made of of progressively older volcanoes, with the Big island, of course, being the newest addition.

Oahu is much older than the Big Island, however it does posess several young volcanic cones sush as the famed Punchbowl, Diamond Head, Hanauma Bay Crater, and Koko Head (among several others). Hanauma bay is a magical place, yet sadly overrun by tourists (and thus losing much of its natural beauty). However you can learn quite a bit at the visitor center at the summit entrance.


Hanauma Bay, Oahu, Hawaii (c) Matt Dotseth 2016


Some lava flows have been identified within Hanauma bay that are approximately 3,000 years old, and thus is still a potentially active volcano. However unlikely, it is possible that Hanauma and several craters could still hide a lurking active volcanic system under Oahu! Again, this is unlikely, but fun to ponder.

The Big Island is the main show, with Kilauea adding some 5 acres of land after the last lava breakout from the 61G lava flow. I haven't had the chance yet to fly over and check it out, as I'm in the middle of going through job interviews, but I fully plan to take a weekend jaunt over to Kilauea to see Pele in action.

As much action as Kilauea is having right now, its much larger neighbor, Mauna Loa continues to stir, and is continuing its long buildup to its next eruption, which, honestly, could be any time.
Typically the earthquake activity has been concentrated on its SW flank, but on its ENE flank today, there is a series of shallow quakes occurring. This is a little unusual for any quakes to be in that location, so it's something worth watching. When Mauna Loa erupts, it really erupts. 


Mauna Loa quake swarm, Google Earth w/USGS, and my database.




Monday, August 29, 2016

Iceland's Katla Volcano Grows Restless

The Iceland MET Office raised the volcanic alert level to Yellow today for one of Iceland's largest and more dangerous volcanoes, and neighbor to nearby Eyjafjallajökull, Katla on Monday. Katla has long been suspected of leading up to an eruption after the 2010 eruption of its neighbor, and after a series of  Mag 4.0 or greater quakes, followed by numerous other quakes over 3.0, it seems that the time may be near for Europe to prepare for another round with Iceland's volcanoes.

Image from en.vedur.is - Iceland Met Office showing Quake swarm at Katla.

Katla's last confirmed eruption was October 12, 1918, (and it has possibly had some minor subglacial eruptions in later years, though these eruptions are only inferred through glacial floodwater analysis), which means, like Eyja, it has gone quite a long time (from our perspective) without a large eruption. 

An eruption from Katla would likely be many times the size of 2010's Eyja eruption, and 2011's Grimsvötn (Grimsfjall) eruption. Both eruptions suspended air traffic across Europe, and the gases emitted caused things like acid rain and crop damage across Europe. Katla is capable of much larger eruptions, up to VEI 5, like its eruption in 1721, according to the Smithsonian GVP. Eyja's 2010 eruption was categorized as a VEI 4 due to the amount of ash and gas emitted in total.

If Katla is preparing for a major episode (emphasis on IF, there is no guarantee this will actually lead to an eruption), it will likely cause similar economic and travel turmoil across Europe, and locally, will likely result in lots of flooding and damage to nearby roads and bridges, which is common in Icelandic eruptions. Local farm communities to the South and South East of Katla would likely bare the brunt of the damage, however they are sparesely populated, and the fact that Katla is a very well monitored volcano should give people time to evacuate should it get ready to erupt.

For you volcanophiles, it may be a good idea to start checking in on the Mila webcams, which can be found here. The 2010 eruption of Eyja, and the recent eruption of Bardarbunga/Holhuraun were live-streamed through this portal, and did not disappoint.

If Katla does erupt, I'll just post a new blog. Stay tuned.

*****UPDATE*****

According to Icelend MET Office:

"Glacial water is flowing into Múlakvísl river, south of Mýrdalsjökull. Increased conductivity has been measured in the river and gas measurements in the area show high concentrations of sulfur dioxide and hydrogen sulfide. People are advised not to travel near the river, due to gas pollution. It is not uncommon for glacial water to flow into Múlakvísl, causing increased conductivity and gas pollution.

According to local reports, the level of the Bláfjallakvísl glacial river is unusually high. Bláfjallakvísl originates from the northern side of Mýrdalsjökull and people are advised to show caution when crossing the river."

This could indicate geothermal activity underneath the glacier is now taking place...

Monday, June 20, 2016

Moving to Hawaii

It's been a while since I've posted much here, but with pretty good reason. I'll be moving to Oahu, Hawaii in about two weeks. This is first and foremost born out of a desire to move out of San Diego, CA, where - dare I say it - climate change is in full force here. California is experiencing a record-setting heat wave in conjunction with a long running drought. As I am currently writing, the temperature here in East San Diego County has reached an abominable 110 degrees Farenheit, and I'm nowhere near the desert.

Another reason - of course - is that I love volcanoes, and Hawaii's Kilauea and Mauna Loa volcanoes are some of the most active in the world. Kilauea has been in constant eruption since 1984, with no pause in activity. Mauna Loa is currently inflating, and will erupt in the near future (although it is impossible to say when). I want nothing more than to be there, in person, for that show, while helping to provide info, and volunteer assistance with what will likely be a crisis for many if lava flows advance onto people's property.

And of course, I've been in San Diego my entire existence, and my wife and I are due for a change. There are many jobs there for I.T. people (I am a network engineer and admin/CIO by trade), and teaching jobs (my wife currently teaches 5th grade students in high-risk neighborhoods).

The focus of this blog will likely shift somewhat to the Hawaiian volcanoes, at least for a time. Kilauea isn't exactly doing anything different than what it has for the past 33 years, and HVO does quite a nice job of... copying and pasting with minor updates. But Mauna Loa is going to be a big story, at least in the near future, and it will be neat to kind of chronicle the process of inflation leading to an eruption.

In any case, my reports will probably be a little sparse in the next couple of months as I get settled on Oahu (thankfully, extinct). But things will pick up again soon, I promise!

Cheers.

Iceland's Hekla Volcano Primed For Eruption

Iceland's Hekla volcano is ready "To go at any time" according to Iceland geophysicist Páll Einarsson. (Link is in Icelandic). According to him, the Hekla volcanic system is at a higher state of pressure than the 2000 eruptions, and previous eruptions. I've personally been watching this volcano and it's goings-on for some time now, and what I've seen has been a bit worrying.

As pointed out by the article, it's nearly two decade long dormancy has given way to a booming tourist industry, where 40-50 flights occur daily over the volcano, in conjunction with a high population of hikers and photographers. The problem here is that Hekla, unlike many volcanoes, does not typically give much warning before erupting. Most volcanoes at least show some signs of volcanic quakes, which can give some forewarning of an eruption.

Hekla however is not that kind of volcano. Its eruptions are typically sudden and without much warning... but Hekla is having volcanic quakes, which could signal that the next eruption may be much larger than previous ones. As the volcano is not prone to showing much seismicity, rather, gradual deformation when its magma chamber is inflating, this is a bit worrying.

If the volcano is already displaying some warning signs (a 2.5 quake occurred within 48 hours of this writing according to http://en.vedur.is/), this could be all the warning we get.

Many scientists are cautioning against visiting this volcano within several tens of kilometers, as there is simply no way to tell when it will erupt - just that it will erupt in the near future.

Iceland's last major eruption from Bardarbunga's Holuhraun fissure North of Vatnajökull caused soem disruption due to gas emission, but was largely very harmless. An eruption of Hekla - much closer to tourist accessibility, and some small properties, makes this a more dangerous eruption, however the area is sparsely populated. The threats from this volcano would be rapidly melting ice which causes flooding, lahars, pyroclastic flow (due to magma interacting with ice), lava flow, and gases.

The biggest threats are ash (due to aircraft and nearby farmlands) and disruption of flight paths, gases, and flooding.

Keep an eye on this volcano too, Iceland has been very good about posting links to various volcano webcams, when it does erupt, it should put on quite a show.


Sunday, January 24, 2016

Mexico's Popocatépetl Volcano Causes High Alert

There is a lot of bad reporting going on about Popocatépetl in Mexico lately, so I thought it might be a good idea to set everything nice and straight. Some reports are suggesting Popo hasn't erupted since the year 2000. False, it has been in a continuous state of unrest with occasional ash emissions since 2005. That's upwards of 11 years. 

The volcano has been having more frequent and more powerful ash emissions, with multiple dome building/collapse events and small pyroclastic flows for quite some time. The media does love a good panic story, so when Mexico raised the alert level to "yellow", they freaked out. 

Yes, this is a volcano that is dangerous. It is capable of large eruptions up to VEI 5 (but not since  3700 BCE ± 300 years according to the Smithsonian GVP), however it is more than likely going to be (if it has a serious explosion) a VEI 2-3 event, most likely 2. 

The volcano, while quite massive, simply has no recent evidence of an eruption large enough to damage surrounding cities. The real danger from this volcano is not blasts or explosions, rather the fine ash that it generates that can cause lots of problems. It weighs down roofs, it chokes animals and livestock, and creates a fair amount of misery for the surrounding areas. 

It can be expected, depending on the weather, that there would be some ashfall in Mexico city, however Mexico City is not threatened in any serious way by Popo's activity. It's simply too far away at some 44 miles. However the surrounding towns such as Amecameca, Atlautla, Ecatzingo, and Tetela del Volcán would be quite a bit more vulnerable due to their immediate proximity to the volcano. All are small(ish) towns surrounded by farmland.

The Yellow alert raised by Mexico is a precautionary measure meant to prepare residents for immediate evacuation if necessary. It is simply an alert status, not a "MASS EVACUATION ALERT" (in bolded caps) as some yellow-journalists out there are parroting. It is meant to have residents have what they need prepared in case Popo does decide to blow. At this time, nobody is actually being evacuated, as some outlets are suggesting.

The base of the volcano is surrounded by dense(ish) forests which don't show any signs of stress (except for human logging) past about 2 miles from the summit. This probably rules out the danger to towns for pyroclastic flows. Gas and ash probably would be the worst it can do to the surrounding areas. At the most, a 10km exclusion zone would probably do the trick to keep people safe. 

That does not mean evacuations won't occur if activity increases and heavy ashfall starts making life miserable for people, but it's not happening right now. 

I will update this post if anything changes.