Another Quake Swarm At Katla And Whispers Of Impending eruption [UPDATED 3-5-2012]

Katla volcano has had over 16 quakes in the caldera area in the last 36 hours. 11 of these were in the last 12 hours as of this writing, with most a bit under mag 1.0, but some almost to a 1.9 magnitude. The largest eent was a 2.1 mag quake slightly outside the caldera. Harmonic tremor is also being detected at the volcano, again raising the specter of a Katla eruption. Whether or not it's going to be a small event like the 2011 minor eruption remains to be seen, but one thing is becoming abundantly clear. Katla is waking up, and it will erupt soon.

My guess based on constant observation of this volcano and reading Icelandic blogs and media reports is that Katla will likely have an eruption either this year, or sometime next year. As there are no instruments that can tell us the location of the magma in the chamber, or how much is being injected, it is very hard to tell, if not impossible to predict what will happen. If history is any guide, we might be expecting a very large eruption sometime soon. But then again, looking to history for apparent patterns in volcanic activity is something we humans do, even if it truly means nothing in reality.

A large Katla eruption has been expected after its neighbor blew up in 2010. Eyjafjallajökull has been characterized by some volcanologists as being slightly connected to Katla's magma chamber via a lateral dike-like structure. Historically speaking, each recorded eruption at Eyjafjallajökull was followed usually within months by a Katla eruption. But this sort of proves how historical "patterns" may not always be so. It has since been almost two whole years since Eyjafjallajökull erupted, and despite the tiny eruption from Katla (which may have been a result of left over magma from Eyjafjallajökull's eruption via the lateral dike I mentioned), Katla has remained restless, but non-eruptive as some people predicted.

Time will tell, but it's probably a good time to start really keeping a close eye on what's going on at Katla, especially for Iceland and Europe. Due to its location next to Eyjafjallajökull, it is quite possible that a large ash producing event from Katla would have very similar effects on the Eurozone that Eyjafjallajökull did when it exploded. This could easily cause more economic hardship to Europe, at probably the worst time to do so if it were to erupt rather soon.

I'm going to be keeping my eyes peeled on Katla this week, and if more activity occurs, you'll hear about it here!

*****UPDATE*****

Another swarm of quakes were recorded today at the Katla caldera. 4-5 quakes ranging from less than 1.0 to around 1.5 occurred within an hour period. Again, this is most likely more magma dike intrusion into the caldera system.

El Hierro Eruption Continues At Low Level

While the harmonic tremor readings are nearly flat, and visuals on the surface of the ocean have been few and fr between, the El Hierro submarine eruption is continuing at a low rate. For the last few days, the "jacuzzi" and stain area have made faint appearances, and water temperatures over the vent are still high enough to generate a steamy haze over the vent area. Today the jacuzzi area is a bit stronger, even though harmonic tremor is about the same as it has been for the last week or so.

The earthquakes to the West of the eruption zone have been continuing, varying from up to 20 quakes per day, down to a low of about 7. They are getting shallower in this area, indicating the possibility of more magma movement possibly to a different area. This could explain why "Bob" (the unofficial name for the submarine volcano) has shown minimal activity, because magma may be finding another route through the crust. It could also be that "Bob" is simply re-pressurizing, and the renewed jacuzzi and heat activity could indicate that the cone itself is heating up again and getting ready for another round of eruptive activity. Only time will tell. This could simply be underwater cooling and degassing, but this would not account for the activity today (the ocean is a GREAT heat sink, especially for cone building events such as this).

There have been regular scientific expeditions to the eruption area, with several scientific vessels taking bathymetry readings, and sonar scans of the ocean floor. From what I've read on Earthquake-report.com (they are fortunate enough to have a local reporting for them and taking daily photos), an ROV missions is planned in the near future to take direct video of the vent area, however due to currents and sometimes bad weather, they haven't had much luck getting the remotely operated vehicle deployed yet (they are insanely expensive, so they will always err on the side of caution when it comes to this equipment).

So until we have direct observations from the sea floor, it is hard to tell what the state of the eruptive cone is in at this time. All we can infer from tremor, and surface observations is that this eruption is continuing at a low level as it has been for the past week or so. This could change at any time.

In a previous post about El Hierro, I pointed out the similarities between El Hierro and the Hawaii island chain. While Earthquake-report.com picked up on this idea as well, they erroneously compared this eruption to that of Kilauea, instead of its newer and less active neighbor, Loihi. The surface eruption on Hawaii's Kilauea volcano is unimpeded by ocean water, and is able to create stable channels for lava to flow onto the surface. Loihi (first detected in eruption in 1996) is a submarine volcano SW of the Kilauea summit, and has periods of activity followed by long periods of dormancy, and has a lot of the same characteristics of the El Hierro submarine eruption.

While it is my belief that El Hierro, like Hawaii, is a "hot spot" type volcanic system, the dynamics are different from Hawaii. The chemical makeup of the lava is different, the location is certainly different, and instead of an underwater shield volcano (like Loihi), this seems to be a mere cone building event not separate from the main volcanic system at El Hierro.

Hot spot volcanic systems like the Hawaiian and the Canary islands can have long period of eruption like Kilauea, or short periods of strong activity... really the range of activity these spots are capable of is huge. El Hierro might be entering a phase of long term activity given the quakes, their locations, and the duration of what people thought was probably going to be a very small event. This is a volcano still worth watching, and is of great scientific interest.

*****UPDATE 2/27/2012*****

Activity at El Hierro is unchanged. Low and almost nonexistent harmonic tremor, coupled with light degassing and small jacuzzi visible. Probably the actual eruption of "Bob" the underwater cinder cone is over. However GPS data indicates uplift of the island of El Hierro itself, and quakes are clustering at the northern end of the island. El Hierro appears to be inflating, and it is not unreasonable to think that another cone building event, possibly on the island itself, may occur in the future. When is impossible to say.

More Activity at Salton Sea (Salton Buttes) California

The Salton Sea is shaking. Over the last few weeks, many very shallow tremors have been occurring on the fault line that runs through this SE California farming town. The largest events so far have been around 3.5 in magnitude, and are clustering on the SE shore of the Salton Sea, just East, and overlapping, the Salton Buttes; lava domes that were extruded along this spreading fault line some 5,000 years ago.

The Salton Sea is home to a geothermal power plant, as well as having the unfortunate location of being right on top of a spreading rift that includes the Cerro Prieto volcanic center, near where the Easter 2010 Southern California quake struck, shaking San Diego County and Mexico with a 7.2 magnitude quake.

The region has shown many quakes since the 7.2 quake, most of these fault stress adjustments and minor slippage events. It is likely that Southern California will experience heightened seismicity for decades. This is actually good for Southern California since tectonic stresses are being released slowly. When quakes stop in this area, it's time to worry about another big one like the Easter quake. Fortunately for Californians, our buildings are built to withstand up to a magnitude 8.0 quake with little to no damage. The same cannot be said for the majority of Baja California and Tecate, which experienced heavy damage from that quake.

As the Salton Buttes are classified by CalVO as an extreme risk for future eruption, the general consensus seems to be that volcanic activity in the area is expected in the future, however the area is currently not monitored by CalVO. It is for that reason that I'm planning to go to the area to look for myself to see if there is anything strange like gas fissures, plant kill, or heightened activity of the various mud volcanoes in the area. Other indicators of rising magma could be dying fish in the lake, however that's actually pretty common since the lake is one of the most polluted on the planet.

The Salton Sea is surrounded by agriculture, and ghost towns, where abandoned cars and other vehicles, as well as garbage and toxic waste, were carelessly tossed into the Salton Sea. The agriculture activity is responsible for a lot of the pollutants and toxins in the lake. It is common to see dead fish and other animal life on the shores of this lake. Locals would probably rather starve than eat the fish out of that lake. So dead fish int he lake would not be a good indicator of activity, unless an extraordinary amount of fish ended up washing to shore.

In any case, I hope to have some pictures and direct observations of this area soon... gas has now climbed to an astonishing $4.59 a gallon for 87 octane and is expected to rise sharply in the coming days/weeks. So if you'd really like to see some firsthand pictures, video, etc, please do feel free to toss me a couple of bucks on my Google Donate button, which will go directly to this planned trip. I'll probably end up going anyway, but it would make a difference to me if the readers of this blog chipped in for the trip... there is something going on out there that hasn't happened in a while, and I, like you, am quite curious. 

Costa Rica's Rincón de la Vieja Volcano Erupts

Rincón de la Vieja, Costa Rica's largest volcanic complex, is experiencing an eruptive phase after 14 years of quiescence. Tremor and explosive activity has been reported by Wired.com Eruptions blog, and local Costa Rican news sources. The explosions were not damaging to surrounding areas, and are reported to have been contained inside the most active (middle) crater of Rincón de la Vieja. Volcanologists say that this is not the result of new magma being injected into the crater, rather this is a phreatic eruption.

Phreatic eruptions occur when water seeps into cracks or fissures, and comes into contact with cooling magma or superheated rock, which in turn causes the water to flash into steam, creating enough pressure for an explosive event. These types of eruptions are considered to be one of the least dangerous types, however they are still quite dangerous as they can occur with little to no warning. These types of eruptions generally do not generate any seismic signals until they actually occur, and are not able to be predicted. They are typically small eruptions, however larger phreatic eruptions, more specifically, ones that can create a 'maar' have occurred in many other volcanic systems, such as the Soda Lakes maars in Nevada, or the Ubehebe craters.

It is probable that this will be some of the only activity for now from Rincón de la Vieja for a while, unless new magma is injected into the chamber. It is anyone's guess at the moment as to if this has occurred or will occur. However the Costa Rican government would be wise to excersize caution, as a 1966 eruption caused a very large, VEI 3 sized eruption, which produced many deadly pyroclastic flows. An earlier eruption in (around) 1820 BC produced a much larger VEI 4 size eruption, which produced the Río Blanco tephra layer, was the largest eruption of the volcano that we know of.

Rincón de la Vieja is the site of geothermal drilling and exploitation.

Rincón de la Vieja does have the potential for extremely explosive events, and it is looking like the volcano is awaking from its slumber... at least for a little while. It is entirely possible that after these phreatic explosions, that will be all and the volcano will go back to sleep. I for one wouldn't plan any trips to the summit any time soon, and would opt to admire the volcano from a good distance!

More Shallow Quake Swarming At Salton Sea (Salton Buttes)

The tectonic activity continues at the Salton Sea (Salton Buttes) fault area in California, as many tremors at very shallow depths (some have an odd depth recorded of 0.00 km) in the same region as the previous swarm, directly on the 'corner' of a transform fault line. Activity in the area has been elevated since a 7.2 mag quake struck the Mexico/Southern California region in August of 2010. This area of activity is on the same fault line.

These quakes are most likely tectonic in nature and not related to magma intrusion, however the area is a geothermal development area, and does have several small rhyolitic lava domes which are exposed on the South shores of the Salton Sea. The area has mud volcanoes, and at least one geothermal power plant. The newly minted CalVO (California Volcano Observatory) classifies the Salton Buttes area as a high risk for future eruption, so they seem to think the area will most certainly see volcanic activity one day.

Given the seismicity in the surrounding area, from San Diego county up to Los Angeles County, it is clear that the faults in the area were shaken up by the 7.2 Easter quake. This can be a good thing, or a bad thing. The more energy slowly released by some fault lines can diffuse crustal tension and prevent larger earthquakes from occurring... but they can also create tension at other faults that are not in motion, such as the Los Angeles area of the San Andreas Fault, which has shown very little activity since the large quake south of the border.

It is good advice to keep an eye on this quake swarm. The USGS has so far not released any statements on what the cause of the quakes are, from minor tectonic activity to possible dike intrusion, so I'll keep most of the speculation to a minimum. If USGS has any info on this current swarm, I will update this post.

*****UPDATE 2/23/2012*****

CalVO does not monitor the Salton Sea as of yet, so there will probably not be any incoming USGS analysis to these events.

A 3.0 magnitude tremblor struck the swarm region on the 20th of February, as well as a continuing swarm of smaller quakes at very shallow depths of less than 1 KM. Something is going on over there, I might actually take a trip to the lake and quake area to see if there is any indication of gas release or plant kill. Gas is close to $4 a gallon, and in some areas is much higher (almost $4.50/gal) so I'll need to see if I can afford such a trip. This area is getting more interesting by the day.

*****UPDATE 2/26/2012*****

A magnitude 3.2 quake struck the same region today,a s well as several smaller tremblors. These also took place at depths of less than 2km, with the shallowest quake at a depth of .10km. Gas prices are horrendous right now so I will need to wait until this weekend to make a trip out there to see what's going on with my own eyes. Hopefully nothing out of the ordinary and just the normal "California shuffle".

Volcanoes and Doomsayers

Humanity as a whole has either revered, or feared volcanoes depending on the culture experiencing this geological process. Some cultures deify volcanoes and associate them with various gods, while others fear volcanoes as a malevolent and destructive force. Science has explained a great many mysteries of volcanic processes since the dawn of man, but with progress on the scientific front comes resistance from the spiritual front. Such has been the case since anything resembling the scientific method has been used.

From religious fundamentalists who believe in the "End of Days", to conspiracy theorists who postulate that governments around the world can actually make volcanoes erupt, volcanoes in the media have had a bad rap since nearly the beginning of written language.

My blog, which is really catching on thanks to news organizations, other bloggers, and enthusiasts (my blog has recently overtaken several in Internet ratings, probably due to the fact that I actually vet my information, and check my spelling and grammar!), is dedicated to the idea that science and the scientific method are better used to explain the reality in which we live than say, spiritual or pseudo-predictive opinions. That all being said, I find it both amusing and frightening that information about volcanoes is used in the realm of spirituality to frighten or persuade people into believing that the end times is upon us.

Let this be said and understood. The Earth IS billions of years old. It HAS hosted many generations of life from single celled organisms to macroscopic life forms that inhabit and in some cases dominate the planet on which we live and grow. From amoebas to dinosaurs, from small simians to humans, this planet has a rich (and provable via the fossil record) history of life over countless and unfathomable amounts of time. This time has been filled (on this planet) with geological events, cosmic events, and plenty of important biological events. To consider that we are in some way special and unique in this span of time is, in my view, wholly foolish. We are but specks of dust in the grand scheme of the cosmos, and our planet is unique.

Volcanoes are definitely powerful forces. They do indeed inflict destruction on civilized man, but also provide benefits of which news and religious organizations often fail to recognize. Why, we might not even exist if it weren't for the volcanic chemistry set that the Earth is made of. Volcanic soil produces some of the most fertile land that we are capable of farming due to the minerals that it creates. Volcanic processes create new land and real estate. They fuel our economies in some cases when benign eruptions draw tourists to our towns. They create some of the most spectacular and awesome landscapes that we've come to know and love (take my banner on my page for example, a panorama I took of Crater Lake in Oregon during a gorgeous day!). Or how about the materials we use to make cement, roads, bar-b-que pits, rock gardens, and more?

Yes, volcanoes can and do visit the occasional mass destruction on our planets inhabitants. But they do give as good as they get. If this planet had no volcanoes, we wouldn't even exist. So before anyone goes on a tirade about "the impending eruptions of super volcanoes" or "Anak Krakatau (or as the less informed know it, Krakatoa) is going to wipe out all life in the Southern Hemisphere", you may wish to re-think your position on volcanoes. After all, chances are 100% that the ground you are standing on had an igneous origin, or that the materials you use in every day life are created by volcanoes.

We as humans tend to build structures and societies where the land can produce crops, and the scenery is impressive. And it is no coincidence that this usually means that you're building on a former area of intense volcanism, due to the resources that are derived from volcanoes. We currently generate power, farm crops, harvest cinders for gardens and building materials, chemicals like sulphur and gases, pumice for soaps and exfoliation products, even toothpaste... the resources we actually get vs what we give back from volcanoes are one sided in our favor. So before demonizing volcanoes and blaming them for an impending apocalypse, try and think of all the things they provide that make your life easier, and then think about how absurd it is to think that a volcano will (at least in our lifetime) end life on the planet as we know it. Chances are good that aside from a volcanoes small radius of destruction, that in the end, everyone benefits.

That's the truth of the matter.

Katla Volcano Showing More Tremor

Katla volcano in Iceland has been showing more harmonic tremor pulses as well as minor earthquake swarms within the caldera. This has been typical of Katla for almost a year now ever since it's very minor eruption in mid 2011. Icelandic scientists are quite sure this is minor magma dike intrusion into the caldera system. Katla will erupt in the future, however when is anyone's guess, but it will be sooner rather than later.

The winter in Iceland usually calms geological processes while the ice accumulates, but during spring/summer, the massive amounts of ice start to disappear, making it easier for gases to escape and making the potential for volcanic activity a bit higher. Some scientists believe that melting glaciers on volcanoes can initiate a 'rebound' effect on volcanoes that were covered in ice, resulting in a volcano that is able to erupt more easily. The rebound effect can be seen in the USA's Great Lakes region, an area of former glaciation that is rising geologically very fast (around a couple of cm a year) after the ice sheet retreated following the last ice age. This leads scientists to assume that in Iceland, volcanic activity can actually be affected by the seasons. While this has not been 100% proven and made scientific cannon, it is a compelling theory. Scientists have long theorized that the continent of Greenland might be hiding 'suppressed' volcanoes under the vast plains of ice that make up most of the continent. Again, this has never been proven as the ice is far too thick for a geological readout.

But Katla doesn't seem to mind the ice and snow. Last year it had a minor subglacial eruption (or what is firmly believed to be one) that resulted in glacier outburst floods and damage to a bridge and road. This occurred despite the massive glacier on top, and has erupted before through many meters of ice. I'm not entirely sure Icelandic volcanoes are affected much by being capped with Ice. Grimsvotn volcano doesn't seem to mind the ice either.

The swarm today was particularly strong at Katla, with over 15 quakes within the last 24 hours, all under magnitude 1.5. but clustered very close to each other in the caldera. Check out the swarm below.

Alaska'a Kanaga Volcano Raised To Alert Level Yellow

Alaska's Kanaga Volcano in the Aleutian Islands is showing signs of activity according to seismicity and observations made by AVO. The latest report states:

"Possible explosive activity and a likely ash cloud indicate new unrest at Kanaga Volcano. AVO is increasing the Aviation Color Code to YELLOW and the Volcano Alert Level to ADVISORY.Volcanic tremor was detected from 15:23-15:27 UTC (6:23 AM AKST) followed by numerous small events for about an hour at Kanaga Volcano. A possible weak ash cloud was also detected in AVHRR satellite data from 15:35 UTC about 39 km (24 mi) NE of the volcano.This new unrest indicates a possibility for sudden explosions of ash to occur at any time, and ash clouds exceeding 20,000 feet above sea level may develop. If a large, explosive, ash-producing event occurs, the local seismic network, satellite ash alarms, infrasound, and volcanic lightning will alert AVO to the new activity."

Kanaga's last eruptive phase was in 1994-1995, and produced large ash plumes reaching up to 20,000 meters. 

Japan's Mt Fuji May Be Preparing To Erupt

Volcano-Report.com is reporting that Japan's Mount Fuji (Fujiyama) volcano is showing signs that it is getting ready to erupt. While translating Japanese to English using Google translate leaves much to be desired in terms of readability, the news story (in Japanese) appears to be saying that fumerolic activity and steam emissions have increased, with an unclear anecdote about a 50m wide "new" crater. The only picture I was able to find (below) was a bit grainy, and appears to be showing a snow-less crater on a very snowy mountain. I cannot personally confirm whether or not this is actually a picture of Fuji as there are no other identifiable landmarks in the photo. 

Image from Japanese media of a supposed "new" crater on Mt. Fuji (Fujiyama)

Following the Japanese 9.0 megaquake, there was a magnitude 6.4 quake slightly West of Fuji at it's base. Other quakes of smaller magnitudes (4.0-5.5) have also struck within 50km of Fuji.

While it is unclear from the photos if this is truly a new flank eruption of Fuji (I imagine if the weather was cloudy that people might not notice, but the volcano is easily seen from a great many cities in Japan from a great many angles), the photo does not seem to have an ash layer over the snow. The recent eruption of Mt Etna in Sicily occurred in a supposedly similar fashion, with a cone building flank eruption producing lava flows on a snowy landscape. The ash was clearly visible on the snow for many days.

Mount Fuji last erupted in 1707, in what is considered its largest historical eruption. This eruption was characterized by a massive flank explosion that left a very large crater on the East side of the mountain. This eruption devastated villages nearby, and was strong enough to cover Tokyo with ash. Many current communities in the area are actually built on thick historical lava flows from this event. Nobody alive has ever seen Fuji erupt, but they all know the stories from well-kept records of that period, and the last eruption was very well documented in Japanese historical archives.

Over 100 cinder cones and vents dot the landscape around Fujiyama, highlighting the unpredictable nature of eruptions from this volcano. Fuji could start out with a cone building phase, and enter into a more explosive phase, or this could be all that happens at Fuji for the next hundred years.

If any new information comes available, I will update this blog immediately.

NASA MODIS Satellite Captures Remote Eruption

Some volcanoes are simply too remote, or obscure to have regular monitoring by human eyes. That's where NASA's MODIS satellite comes in to fill the gap. From monitoring volcanoes in Alaska's Aleutian islands, to the most remote volcanic islands like Ascensión, MODIS has been able to capture remote volcanoes doing their thing while nobody's watching. MODIS just captured the very remote and uninhabited Tinakula island in a steam emitting eruptive phase. This would have gone unnoticed by us humans if not for the satellite.

Image from NASA MODIS Satellite of Tinakula in eruption.

The isolated volcano is surrounded by a series of small coral atolls, and sits about 20 miles NNW of Nendo Island of the Solomons. The island was not always uninhabited. An eruption in 1840 produced catastrophic pyroclastic flows that covered the entire island, and annihilated the small indigenous population that called it home. No efforts by anyone have been made to re-establish a population (gee, I wonder why?). The volcano is frequently seen in eruption by passers by, and has been since colonial times.

NASA's MODIS satellite has been busy lately keeping track of the slowly erupting Cleveland Volcano in Alaska, as it continues to be on alert level Orange (out of green, yellow, orange, red) as it effuses a slowly growing lava dome at its summit. AVO speculates that the slow eruption could burst into a more explosive phase at any time, so flights over the volcano are not permitted at this time.

MODIS has thermal sensors to detect heat anomalies, ash emissions, and steam. With a high resolution telescopic camera, the images it is capable of producing are highly detailed. It is capable of seeing wavelengths that our eyes cannot, which proved useful in detecting lava flows from Nyamuragira volcano in the Congo, as well as the new eruption of the long dormant Nabro volcano in Eritrea.

El Hierro Volcano Eruption Winding Down

After 3-4 days of continually weak harmonic tremor at El Hierro volcano, it appears that the eruption is starting to wind down on the underwater cone. This does not mean that the risk of further activity, or other eruptive vents opening is over. Over the last few days, around 20 or so earthquakes a day have been recorded to the West of "Bob" (the tentative name for the underwater cone), gradually rising from 20KM beneath the surface, to 7KM yesterday, indicating a rapid dike intrusion. The GPS data shows a stable (not deflating) surface, which indicates that the magma chamber is still quite loaded.

Currently, the harmonic tremor at El Hierro is at a very weak level, with very minute occasional spikes (most likely those spikes are related to the earthquake activity to the West, and not from the vent itself), with the trend going lower and lower. This of course could indicate that the vent has collapsed and is simply re-pressurizing, and is merely gearing up for more action, but as the tremor has been gradually decreasing to the point it is now, my guess is that the vent is sealing up to the point where it can no longer erupt without some massive pressure from the magma chamber.

If anything further happens at El Hierro, rest assured I will cover it. For now, it may be time to finally say, "Bob has gone to sleep"

*****UPDATE 2/17/2012*****

Last evening, there were some images captured of nighttime smoking lava stones seen on camera, a bit to the East of "Bob", even while harmonic tremor remains nearly flat, proving once again that HT readings often do not correspond to actual lava emissions. HT is flat again today, although there was a 2.5 mag quake in the area which residents probably felt a little bit. There is no visible stain on the oceans surface, however a research boat and her crew reported smelling sulphur directly over the vent. It's really anyone's guess at this point as to what the situation looks like. It could easily be a "pillow lava" flow going on at the ocean's floor with occasional rising lava balloons (gas filled lava blobs that combust on the the ocean surface). Pillow lavas typically do not emit underwater "smoke" nor do they release a large amount of gas (it's more like squeezing toothpaste out of a tube, and is fascinating to watch video's of). At least this is my theory. If anything else happens, I will post another update.

*****UPDATE 2/18/2012*****

Tremor still extremely low, but surviving. It is probable some activity is occurring underwater, however any activity is weak with no visible "jacuzzi" area, and there has been no visual observations of lava balloons, or a stain. Current webcam views show a calm blue sea, with no disturbances.

Earthquakes however continue to pick up, with approximately 20 quakes a day over the last few days, and a 3.3 magnitude tremblor this morning. This definitely says that there is still a large, and active magma chamber underneath the island that probably has more in store. With the final collapse of "Bob" and cessation of eruptive activity, it is entirely possible that the magma must find another way to the surface in another location. With the locations and depths of the current quake swarms, it looks a bit likely that this might end up being off of El Hierro's SW coastline, directly W of the main vent.

This could end up being the last post about El Hierro for a while, as other volcanoes demand attention.

New Earthquake Swarm in Katla Volcano

Katla volcano in Iceland had a swarm of quakes within the caldera region today, with the largest magnitude hovering around 2.5. Quake swarms have been a common occurrence in the volcano since its small, but damaging eruption in 2011 where a glacial outburst flood (jokullhlaup) destroyed some public infrastructure (bridges).

Blogger Jon Frimann, who is typically the best direct source for Icelandic volcanic events, has been monitoring what he considers to be magma dike intrusion beneath Katla since this eruption. Katla volcano was expected to have a large eruption after the eruption of Eyjafjallajökull in 2010, but has since proven that attempting to predict volcanic eruptions of any kind is a foolish endeavor. Many Icelandic scientists have been quoted as saying, "It's not a matter of if, but when". We are on the "when" stage of an eruption for Katla now.

Katla has the potential of generating huge eruptions (of a probable VEI 3) if it was to get a large injection of magma into its chamber. Currently, it appears that if this is indeed magma dike intrusion (which is definitely a strong possibility with this volcano), the intrusion appears to be quite minor. It is probable that any eruption from Katla at this time may be very small, as larger magma intrusions generate much larger quakes.

However, if magma is able to create a solid and consistent channel to the surface, there is the possibility for a stronger eruption. Katla volcano is overlain by the Mýrdalsjökull glacier, many meters thick. So an eruption of Katla would likely be a repeat of the Eyjafjallajökull conditions where hot magma/lava hits glacial ice and creates a large and fine ash cloud. This of course waits to be seen.

Below is the tremor graph for today's quakes, showing both the location and timeline for the quakes.

Image copyright Iceland Met Office.

An earthquake swarm also occurred at the Hengill volcanic area, but this is mainly due to geothermal power development in the area. This is quite similar to the seismicity at the Clear Lake volcanic field in California, USA.

Golden Trout Creek Volcanic Field Experiences More Earthquakes

The quake swarm at Golden Trout Creek in California has added several new tremors today in what is looking more and more like magma dike intrusion. The quake area (as shown in a previous post) is less than a mile away from two separate hot springs; Joran Hot Springs, less than 1 mile from the swarm area, and a thermal area to the West of the quake region (or what appears to be one on satellite). The quakes started out at depths of around 8KM, and in the course of one day have progressed to a magnitude 2.3 at a depth of 3.8KM.

There were four magnitude 2.0 or greater quakes today in the area, with many smaller tremblors dotting the area. Aside from the obvious trend in quakes getting shallower, the area being very near thermal hot springs begs the question, "Is this Pleistocene/early Holocene volcanic center having a magma intrusion"? My guess at this point is yes, however the newly minted CalVO (Formerly LVO) has yet to publish any analysis. This area does have active fault lines, and it could be that this is only tectonic, however the area is known for at least 4 monogenetic cinder cones, and a random cone building event may not be out of the question.

I do try not to speculate, as many other bloggers have done, in the name of good journalism and science, but the trend is starting to look very convincing.

Image from Google Earth with USGS overlay detailing the location, magnitude, and depth of the most recent quake. 

If this does turn out to be an eruption (keep in mind, if this is magma, it still has around a mile or so to go before it breaches the surface), it would be the first in California in nearly a century. The last eruption of any kind occurred at the Lassen Volcanic Complex in Northern California in 1915, when one of the Sierra Nevada range volcanoes entered into a two year long eruptive cycle. To my knowledge, that is the only eruption in California you can actually find (black and white) pictures for.

This could easily turn out to be nothing, and the area is so remote, people would not be in harm's way whatsoever. If anything, this might turn out to be a nice tourist attraction for thrill seekers, much like the tourist who flew to Iceland during the April 2010 eruption of Eyjafjallajokull (I'm too lazy right now for the umlauts, sorry Nords!). This would be pretty great for California, as my home state depends heavily on tourism for a lot of its revenue. However, wishful thinking does not an eruption make, and only time will tell.

 *****UPDATE 2/15/2012*****

A 2.3 magnitude quake occurred today at a depth of only 3.8KM (*2.36 mi) indicating a strong, and rising source of seismicity. If more quakes occur in the same location at even shallower depths, I would start thinking that this is definitely volcanic related activity.

*****UPDATE 2/24/2012*****

Another round of tremors hit the same region today, this time at a LOWER depth of 8.0 km (down from 5.0). Three quakes ranging from mag 1.7-2.1 occurred within a 24 hour period in the same location as the previous quakes.

Eruption at El Hierro Slows, But Quakes Increase

The harmonic tremor at El Hierro has been extremely low for the last couple of days, but the volcano is still weakly erupting magma, and mostly degassing. However there were a record of over 20 earthquakes yesterday and into today, with the quakes becoming shallower and shallower, possibly a precursor for another vent in the SW part of the island off the coast. The magma chamber is not done yet with El Hierro.

The harmonic tremor is at a low point due to probable vent collapse, and re pressurization of the chamber (think of it like putting your thumb, or a cork, in a running garden hose, but on a much more massive scale). The pressure will build up and the eruption of the current vent will either resume, or the magma will find another route to the surface. It is anyone's guess where and when, but it seems likely that the new vent if it does pop up will be to the West of the current cone (Bob).

The current tremor and analysis from El Hierro volcanologists confirm this, and now the island waits to see the next phase of this historic event. More than likely, this will result in another submarine cone building event. If another cone/fissure does erupt in another location, you can be pretty sure that the first cone (Bob) will stop erupting as magma diverts to an easier route. This may be already taking place, with harmonic tremor so low, and quakes so numerous and shallow, it could very well be that "Bob" is dead.

This would actually end up being a good thing for the village of La Restinga as their main port and tourist spots have remained closed out of an abundance of caution, and all sea faring routes have been cut off. This has hit the economy hard. An eruption to the West of "Bob" would be of minimal consequence to business, especially if "Bob" is confirmed to be done erupting and the government re-opens boat traffic to La Restinga (not to mention the hotels and cafe's).

El Hierro Tremor Increases, Activity Resumes

2/09/2012

After a two day break from anything major at El Hierro, the volcano is gradually picking up steam again. Tremor for today shows a very slowly increasing amplitude, and webcam images show a very prominent stain with jacuzzi area once more. Some smoking stones could be seen on the water's surface.

Seismograph from IGN for today which shows slowly increasing harmonic tremor.

The activity at El Hierro is hard to predict, and even harder to forecast. At this point, the eruption is clearly a much longer term eruption than scientists could have expected, and it appears to have no real end in sight. Earthquakes and tremor are persistent, and the cone shows no signs of stopping its growth any time soon. I am awaiting the results of the latest survey of the cone to see whether or not it is getting much closer to the surface. At last glance, it was approximately 35M below the sea surface, but the cone has suffered several collapses so this is probably no longer accurate (could be higher, or lower).

There have been a couple rumors (but they are ONLY rumors) of thermal areas being detected on the terrestrial island, but this has NEVER been confirmed. A good NASA snapshot could easily kill that rumor, and one will probably come along eventually. 

*****UPDATE 2/9/2012-2/10/2012*****

The tremor is still increasing, while surface activity remains unchanged. What this means at this time is unknown, but could indicate further magma injection into the El Hierro magma chamber. This has been steadily increasing since early yesterday until now, with tremor showing no signs yet of abating or decreasing. This probably means further underwater explosive activity will occur within the next day or so. The reinvigorated tremor readings from IGN can be seen below.

*****UPDATE 2/11/2012*****

The tremor at El Hierro is decreasing again, after three days of moderate and sustained tremor. A stain is still visible on the water surface, and a jacuzzi area comes and goes.

Decreasing tremor at El Hierro today.

*****UPDATE 2/13/2012*****
The harmonic tremor readings at El Hierro volcano in the Canary Islands have been erratic the last couple of days. Frequent fluctuations between medium-strong, to barely readable have been the pattern the last couple of days. This most likely indicates an unstable cone/fissure vent, and consistent magma pressure on the vent. Currently, tremor is low, but picking up, suggesting that the volcano is slowly clearing whatever obstruction may be in the vent.

Below is the current tremor readings for today.

                           

4.3 Magnitude Quake Hits Clear Lake/Geysers Geothermal Field

A much larger quake than normal hit the Clear Lakes/Geysers Geothermal Field area on Monday at about 4:30am, in an area that has seen much elevated seismicity since the development of the geothermal field for power plants. This is one of the largest and most productive geothermal energy sites in the world, with smaller quakes being pretty common due to drilling and the pumping of water into the hot rocks beneath the volcanic field. The quake was a magnitude 4.3 and shook up the entire region as you can see in the below screenshot from Google Earth with the USGS overlay/Shakemap overlay.

Google Earth/USGS Overlay screenshot of the quake area with the shake map overlay enabled.

This particular quake was extremely shallow, at less than 0.40km beneath the surface. This quake is most likely a result of the geothermal drilling in the area, although this is a few magnitudes greater than what is normal in the area. Typically, quakes in this region don't exceed much more than a 3.2, and those are pretty rare.

The newly minted CalVO (California Volcano Observatory, formerly Long Valley Observatory) classifies Clear Lake as a high threat based on the surrounding population, history of Holocene eruptions, and the presence of an active geothermal system. It has been added to the new California volcano monitoring system.

It is unclear at this time whether this is purely a geothermal event caused by power plant development, or if this is tectonic (this is an area that is part of the San Andreas fault line), or if this could mean some magma movement below. This area has not had a magmatic or phreatic eruption in a very long time (probably over 10,000 years). The Clear Lake field is classified as active based on geothermal activity, and a large silicic magma chamber provides the heat source used to power the steam turbines at the geothermal plants. So there is magma down there (most likely what scientists refer to as 'crystal mush'), but it is apparently much too cool to erupt.

This event was not likely related to dike intrusion or injection of fresh magma (the event was much too shallow), and more than likely is a result of underground steam explosions or rock fracturing/slippage. If any USGS analysis comes out I'll post a link to it. Keep your eyes on Clear Lake in the meantime!

Large Swarm Of Earthquakes Occurring at Salton Sea, CA

The Salton Sea/Salton Buttes area, approximately 100 miles from San Diego and San Diego County, is experiencing a long duration earthquake swarm along one of the regional fault lines. The quakes are centered at and around the SE shore of the Salton Sea lake, near to some geologically fresh obsidian domes that were erupted in the area around 9,000 years ago.

The area is known for very active seismicity, and it is entirely possible that the quakes on the fault are related to magma dike intrusion, however the quakes are very shallow, indicating this is probably only tectonic in nature, as any magma at shallow depth would produce things like dying crops (the area is heavily agricultural), probable C02 emissions, and eventually ending up in some sort of eruptive activity (possibly phreatic or dome building). This is not occurring at the moment.

Above screenshot from Google Earth with USGS Real-time overlay. This shows the relative distance of the Salton Sea to San Diego, one of California's most populous and affluent cities.

This screenshot from Google Earth with the USGS Real-time overlay shows the largest event in the last few days, a 3.0 quake, at shallow depth.

In the second picture, you can see the tectonic fault as a red line. This is a transform/spreading fault. The quakes occur on a stress point for these faults, so these are probably purely tectonic in nature. The USGS and newly formed CalVO (California Volcano Observatory, formerly LVO, the Long Valley Observatory) does classify this area as a "High to Very High Threat Potential" for future eruption. The statement from their new web page says this:

"The Salton Buttes lie within the Salton Sea Geothermal Field located about 145 km (90 mi) southeast of Palm Springs in Imperial Valley, California. The geothermal system is fueled by heat emanating from zones of partially molten rock (magma) deep below the Earth’s surface. Eruptions occurring about 400,000 years ago were followed by a long lull in volcanic activity until about 18,000 years ago. The most recent eruptions, which took place about 9,000 years ago, started explosively, then progressed to relatively gentle effusion of dense, glassy-looking (obsidian) lava domes. The Salton Sea Geothermal Field, which currently produces enough power to supply about 325,000 homes, has persistent small to moderate earthquakes related to the geothermal system and to movement along regional faults. Monitoring of earthquake activity began in the 1930s, and the dense seismic network installed in the 1970s is operated by the USGS and the California Institute of Technology (Caltech). The available data are insufficient to establish a pattern of volcanic activity to determine the likelihood of eruption. The high heat flow from the area and relatively young age of Salton Buttes, however, attest to the potential for future eruptions."

The region was recently destabilized by a magnitude 7.2 earthquake centered just 40 miles south of the Salton Sea, near Mexico's Cerro Prieto volcano, which also hosts a large geothermal area. Reports from people living near the epicenter told of fountains of sulphuric and foul smelling red water geysers occurring in farmlands during the quake, which ended up contaminating much of the farmland in the Mexicali area. This fault is the same fault line as the Salton Sea, and has seen hundreds of quake occurrences a day since the 7.2 magnitude quake. This, to me, says that this is probably the fault line still in motion, but could coincide with geothermal/magmatic movement.

In any case I will be keeping a close eye on the Salton Sea, and may even pay it a visit since I actually live in San Diego, and it wouldn't be too much of a drive (gas is VERY expensive out here at the moment however, almost at $4/gal)... about two hours or so. Hopefully, this is purely tectonic and the people out there can relax. If anything new occurs, I will update this post. 

Site Updates

Over the next few days I will be making some format changes to the Volcano Science and News Blog, including better navigation, explanation of myself, donation, and other policies, and eventually including my "favorites" link to provide you with the same resources that I use on a daily basis. I will also be looking for a way to share my Google Earth database that I have been working on painstakingly for years, for your pleasure and maybe your research projects. Keep your eyes peeled and stay tuned. My aim is to make this one of the most useful sites for all things volcano on the Internet!

New Guinea's Karkar Volcano Spews Ash

The Smithsonian GVP (Global Volcanism Program) reports that an eruption from Karkar volcano island off the coast of New Guinea has erupted, sending a possible ash plume upwards of 10km. Karkar has had historical eruptions in the past, mainly from a cone constructed within a large caldera. Most eruptions have been restricted to the inner caldera, and most have been minor phreatic events, and cone building events, so highly explosive activity is somewhat new in terms of human observation.

Outside the caldera, you can find several tuff rings, maars, and cinder cones that are currently highly vegetated and probably very old. There have been no historical reports of flank eruption from this shield volcano.

The GVP report did not provide many details in regards to this eruption, but here is their statement nonetheless.

"KARKAR Northeast of New Guinea (SW Pacific) 4.649°S, 145.964°E; summit elev. 1839 m

Based on analyses of satellite imagery, the Darwin VAAC reported that a possible ash plume from Karkar rose to altitudes of 7.6-10.7 km (25,000-35,000 ft) a.s.l. and drifted NE and E on 1 February.

Geologic Summary.

Karkar is a 19 x 25 km wide, forest-covered island that is truncated by two nested summit calderas. The 5.5-km-wide outer caldera was formed during one or more eruptions, the last of which occurred 9000 years ago. The eccentric 3.2-km-wide inner caldera was formed sometime between 1500 and 800 years ago. Parasitic cones are present on the northern and southern flanks of basaltic-to-andesitic Karkar volcano; a linear array of small cones extends from the northern rim of the outer caldera nearly to the coast. Most historical eruptions, which date back to 1643, have originated from Bagiai cone, a pyroclastic cone constructed within the steep-walled, 300-m-deep inner caldera. The floor of the caldera is covered by young, mostly unvegetated andesitic lava flows."

Large Earthquake Swarm at Reyjanes Ridge, Iceland

A large and long duration earthquake swarm hit the Reykjanes ridge of the SW coast of Iceland today, and is ongoing. The largest events were slightly above 3.0 magnitude, with many smaller events. The Reykjanes Ridge is part of the underwater seafloor spreading system that occurs between the North American plate, and the European plate, and is prone to frequent submarine eruptions and seismicity. It is unclear at this time from reading bad Icelandic translations from Ruv.is whether they are saying this is an eruption, or simple seismicity (I suspect the translated word "eruption" is misplaced in this article, and might mean "swarm", but as I do not speak the language, that's a guess!).

Tremor Graph from Reyjanes Ridge. Image copyright Iceland Meteorological Office.

Locations of the earthquake swarm (SW). Image copyright Iceland Meteorological Office.

Judging from the placement, location, and size of these quakes, it could be reasonable to assume that an underwater eruption might be occurring, however the depths, weather, and other factors could easily prevent direct observation, and volcanologists would have to infer an eruption from instrument readings (which can sometimes lie). At this point, nothing has been confirmed nor denied.

The GVP characterizes this area as such:

"The submarine Reykjaneshryggur volcanic system off the SW tip of Iceland is part of the Mid-Atlantic Ridge, which is exposed subaerially in Iceland. Numerous submarine eruptions at Reykjaneshryggur dating back to the 12th century have been observed during historical time, some of which have formed ephemeral islands. Basaltic rocks of probable Holocene age have been recovered during dredging operations, and tephra deposits from earlier Holocene eruptions are preserved on the nearby Reykjanes Peninsula."

There are no volcanoes on the Reykjanes ridge that have breached the sea surface in historical time. There is a small 'chunk' of an island along the ridge that was formerly (most likely) a volcanic feature that has since been eroded to a steep walled 'plug', named Eldey, which has the sad distinction of being the last known location of the 'great auk', a penguin-like bird that was hunted to extinction, and the last known living specimens strangled and their eggs squashed by careless hunters. The Wikipedia article on this bird is particularly sad.

I will keep my eyes peeled on the Reykjanes ridge for the time being, and post updates if anything new develops.

Italy's Mt Etna Eruption Intensifies

Mount Etna on the island of Sicily, Italy's most active volcano, is in an eruptive phase again, with explosions occurring minute to minute. The webcam shows many explosive events occurring, with lava appearing quite brightly on the images. The image refreshes about twice a minute, and is not a live 'stream' so it is unfortunately difficult to get a real great picture of what's going on there. The eruptions seem to be emanating from a large cone/fissure system near the summit.

Etna has more or less been continuously active throughout human history, with frequent lava flows, cone building episodes, and paroxysmal events that keep residents on their toes. Eruptions are frequent, and occasionally dangerous, although by and large this volcano poses no threat to the surrounding community, which occasionally has to deal with "vog" (volcanic gas fog) and light ash fall on surrounding towns.

Enjoy watching the web camera, if you can't be there in person to witness the eruption!

Mount Cameroon in West Africa Erupts

Mount Cameroon, West Africa's highest volcano, displayed a brief amount of explosive activity, according to a report from OfficialWire.com. Mount Cameroon is Cameroon's most active volcano, one of many in a SW-NE trending line which include the also deadly and famed Lake Nyos. Cameroon's last major eruption in the 1999 resulted in a long pahoehoe lava flow that stopped just short of the coast.

While some reports of volcanic activity out of Africa are mistaken for wildfire, or plain false, Cameroon's frequent activity and reports from the area are typically accurate. There have been several "less than credible" accounts of some eruptions in Africa, like the supposed eruption in Nigeria around a year ago that turned out to be not only false, but politically motivated (the villagers were feeling a bit neglected by their government, so their local news fabricated a story about a volcanic eruption in an area not known for any previous volcanism). This is unfortunately common in Africa, a continent gripped by poverty, hardship, and militaristic rule.

Whether the Smithsonian GVP publishes this activity in their weekly volcanic eruption update remains to be seen (they publish their weekly reports on Wednesday at about 12PM PST typically). This was the only article I found that cites this activity, however Africa does not have a well-equipped news corps, so reports from the area are typically few and far between, and sometimes full of speculation.

(From Smithsonian GVP):

"Mount Cameroon, one of Africa's largest volcanoes, rises to 4095 m above the coast of west Cameroon. The massive steep-sided volcano of dominantly basaltic-to-trachybasaltic composition forms a volcanic horst constructed above a basement of Precambrian metamorphic rocks covered with Cretaceous to Quaternary sediments. More than 100 small cinder cones, often fissure-controlled parallel to the long axis of the massive 1400 cu km volcano, occur on the flanks and surrounding lowlands. A large satellitic peak, Etinde (also known as Little Cameroon), is located on the southern flank near the coast. Historical activity, the most frequent of west African volcanoes, was first observed in the 5th century BC by the Carthaginian navigator Hannon. During historical time, moderate explosive and effusive eruptions have occurred from both summit and flank vents. A 1922 SW-flank eruption produced a lava flow that reached the Atlantic coast, and a lava flow from a 1999 south-flank eruption stopped only 200 m from the sea."

Powerful Tremor This Morning At El Hierro, Then Significant Decline

Early morning at El Hierro displayed lots of activity at the volcano, as seismic tremor more than tripled the average of the past few days. After this long (3-4 hour) period of heightened activity, the tremor has ground to a near halt for the last 12+ hours. This has become quite the pattern at El Hierro, where there will be periods of heightened explosiveness underwater, followed by a day or so of quiescence, with violent resumption of activity for a few hours after the pause. I would assume that given this pattern, there will most likely be more activity tomorrow morning.

The current tremor graph below:


                               
El Hierro has been a confusing volcano to watch as it has stopped and started its eruptive phase several times. It is unclear at this point whether or not this will be the main event at the volcano, or if there is more in store for this island. There have been rumors of thermal anomalies on the actual island as of late (as per a video on Earthquake-report.com) that are UNCONFIRMED, and probably bogus, as well as rumors of a 2nd vent in the El Golfo region of the island (the North shore). Due to depths off the North shore, this has never been confirmed.

The magma chamber under El Hierro has seismic implications of being quite large, not by any means a monogenetic cinder cone eruption. It is likely that this eruption, and activity at El Hierro as a whole, may continue for some time.

After the activity this morning, El Hierro has been pretty quiet. Late afternoon observations showed a weak stain, and high surf, which has washed a lot of the discolored water away from the vent area. When the ocean calms down, activity will likely be more apparent.

*****UPDATE*****

As I suspected, given the pattern of eruption so far for El Hierro, tremor has indeed again picked up some 24 hours after the last spurt of activity started. The eruption is currently producing elevated tremor, and the occasional flaming lava balloon can be seen on the water surface. Below is today's tremor reading, where you can see the nearly perfect 24 hour relation that has been the case for the last week or so.

The volcano will probably have 2-4 hours of high tremor, collapse the vent again, and re-pressurize about 20-25 hours later resulting in the resumption of tremor... let's see if this pattern holds!

Tremors at Eyjafjallajökull and Katla (Iceland) Today

Several small quakes struck Eyjafjallajökull today, as the seismic swarm continued at Katla caldera in Iceland. Two small flank tremors and one at the summit hit Eyjafjallajökull within the last 12 hours. Numerous other small tremors have also continued under the Mýrdalsjökull glacier capping Katla's caldera system. Several volcano moitoring scientists, agencies, and bloggers have noted the unrest under Katla, and suspect that minor dike intrusion is occurring under the volcano.

The quakes and tremors under Eyjafjallajökull are small, but four have occurred within the last 12 hours. Numerous tremors can be seen under Katla. None of these quakes exceed magnitude 3.0.

In the case of Eyjafjallajökull, it is entirely possible these are not volcanic quakes, rather they could be structural adjustments to the volcano due to it having had a recent eruption (April 2010), and further settling of the volcano on the crust. GPS deformation charts are not available to look at at this time, so it is unclear if inflation or deflation is occurring. Looking at the Iceland Met Office website, all GPS data looks flat on all sites, so their equipment may not be functional at this time (I blame the weather). It will be interesting to keep an eye on, nonetheless.

Eyjafjallajökull caused havoc for air travel to and from Europe during its eruption that began in April of 2010. It was a fascinating eruption to watch, as it started out with a somewhat benign and beautiful fissure eruption on its NE flank (in an area known as Fimmvörðuháls) between the main summits of Eyjafjallajökull and Katla. This eruption lasted around a month, and became quite a tourist attraction, with a great webcam view for a time. After the cone ceased to erupt, there was a short lull in activity from the volcano, before it erupted suddenly and powerfully from its main summit caldera. The eruption was actually rather minor for an Iceland volcano, but due to prevailing winds, and the latitude of the eruption, Europe and Europe's airspace was choked with ash.

This resulted in a months long ban from air travel, while Europe and other parts of the world bemoaned Eyjafjallajökull and the severe inconvenience it brought upon them. Celebrities were stranded, industries were paralyzed, and in the end, Eyjafjallajökull caused billions of dollars to be lost due to economic damage.

Iceland volcanoes have a violent history. Some of its eruptions have been devastating on a global scale, especially the famed Laki fissure eruption that covered a large part of Iceland in volcanic basalt lava, and unleashed incredible amounts of sulphur dioxide into Earth atmosphere for years. This caused a worldwide famine, global cool down, and some say it was actually responsible for sparking the French Revolution! And eruptions from Hekla are famed for the terror they caused to ancient Vikings, who referred to it as "The doorway to Hell".

This has made any news about Iceland volcanoes hot topics for tabloid news, and the usual rabble like Fox or the BBC/Daily Mail. Eyjafjallajökull is NOT currently erupting, nor is it expected to again any time soon. However, volcanoes do have a habit of reminding us that they cannot be predicted in the first place, so vigilance is important with volcanoes, especially the ones that have erupted in historical time. So to be clear, there are NO eruptions currently going on in Iceland, and nothing is imminent. It looks like Katla might be reloading, as well as Grímsvötn (American name). But neither has erupted yet this year.

Alaska's Mount Iliamna May Be Erupting

Indications from USGS seismographs, and the corresponding Google Earth Plugin suggest that an eruption is either about to take place at Iliamna volcano in Alaska, or is already occurring. Earthquake plots from the last week until now seem to indicate rising and frequent tremor, with apparent explosions on the seismographs.

Iliamna is not near any population center, and Alaska is currently experiencing extremely cold weather (down to -48 C) which would hinder anyone or anything from making good direct observations of this remote volcano. It is probable that no observation via satellite, eyewitness, or airplane will be available for some time due to the harsh weather cycle this year. It is highly unlikely that during this period any visual observations could be made except by aircraft seeing an ash plume, which may or may not occur.

Below is a screenshot from Google Earth, with the USGS Real Time Overlay, where you can see quakes within a week (most magnitude 1.1-2.8) in yellow, and the more recent (and larger, up to mag 3.0) coded in orange, denoting a quake in the last 24 hours. These all occur at relatively shallow depths, and are directly beneath the summit, and along the flanks at lower depths. This indicates a rise in magma, and a possible eruption. These signals and the depths at which they are occurring can only mean magma intrusion, as this is a subduction zone, and most non volcanic quakes in the region happen at a much deeper depth (around 210km), not less than 1km. Subduction zones create an exteme amount of energy which heats the rock and creates magma plumes. The volcanoes of the Aleutian arc are very similar to the volcanoes of the Cascades and Indonesia in this respect.

AVO has stated "Since the middle of January 2012 there have been a sequence of earthquakes with several greater than magnitude 2. It is common to have earthquake swarms in the vicinity of Iliamna and the ongoing activity is being closely monitored by AVO seismologists.". They are aware of the current seismicity.

Image from Google Earth with USGS overlay. You can see the localization of the quakes here.

The seismographs from AVO seem to also indicate activity at the volcano. If it has not erupted already, there has CERTAINLY been a large intrusion of magma into its chamber, and will erupt soon.


                                     

Image of AVO seismograph for the last 24 hours. Clearly indicating possible dike intrusion.

Keep your eyes on Iliamna volcano. Especially the AVO seismographs. Unfortunately, this volcano does not have an active webcam to go with the seismograph, and people are very unlikely to be mounting an expedition to this volcano during the inclement weather that Alaska is experiencing right now. Indeed, the only report aside from this one (AVO would never speculate on their volcanoes without proof after all) would be from pilots. So for now, I'll say this. I absolutely suspect an eruption is either taking place at Iliamna currently (or already has), or it will happen very soon.

If there are any updates to this from any official source, I will update this post.

*****UPDATE*****

It appears via seismograph that constant harmonic tremor is now taking place at Iliamna volcano (see above seismograph image). After several large 3.0+ earthquakes, it does appear Iliamna may be erupting, or that there is further magma intrusion into the volcano. If AVO confirms this, it will be the first eruption of Iliamna since the 1950's.

El Hierro Eruption Back to Full Force

The eruption at El Hierro has gained much strength since yesterday. There is consistent harmonic tremor, lots of lava stones floating to the surface of the water, and increased gas emissions. The eruption is now back to the same strength more or less than when it began some months ago. The eruption has had short periods of quiescence as the magma chamber re-pressurizes and explodes after multiple collapses of the underwater vent system.

Below is a live JPG of the current harmonic tremor for today.

                                            
The past few days have seen a dramatic rise in both tremor and surface activity. For the past two days, smoking lava stones could be seen on the live webcam at La Restinga, and CO2 emissions have been steadily rising once again. By all indications, this will be a long eruption with many pauses, but ultimately resulting in either the birth of a new Canary Island. Keep your eyes peeled for its first appearance soon!