El Hierro Activity Ramping Up Again

El Hierro, the volcano in the Canary Islands, may not be quite done yet (as was suspected by a great many following the behavior of this volcano). Although officially the government had lowered the volcanic threat alert level down to "Green", many volcanologists and volcano enthusiasts (including myself) were skeptical about the government's stance on the volcano. This week nearly 20+ earthquakes occurred at depth and some more shallow, as a science vessel captured images of a submarine ash and gas emission at "Bob", the submarine cone of El Hierro.

Other indications point to renewed or at least intermittent activity of the volcano, and much to the chagrin of the authors at Earthquake-report.com, the Spanish government seems to be covering it up, or at least attempting to obscure observations from the rest of the world and scientific community. For what reasons, nobody knows, but I suspect it is another wrong-headed attempt to get tourists to come back to the island.

While the El Hierro submarine vent has been relatively quiet these past couple of months, it has remained in a state of degassing, and the recent emission points to the possibility that the eruption could easily resume at any time. The amount of magma erupted is still far smaller than the volume of the actual magma chamber, and most likely much smaller than the amount of new magma that was injected into the chamber. Due to these facts, it is likely that the El Hierro island could see a longer period of eruptive activity in the future (this could be a precursor event to a more 'traditional' eruption above land, but so far there have been no records of serious GPS deformation, or increased CO2 emission on land).

The volcano caused quite a stir in the scientific community when the eruption was preceded by many thousands of small quakes. The island itself had not had an eruption since the 1700's, which was poorly documented internationally (locally, there is a wealth of knowledge and history), and most people had thought the Island to be dormant. That changed when a presumed eruption started taking place off the coast of the fishing village of La Restinga. The eruption was spotted when dead fish started washing ashore, and a large 'stain' on the oceans surface manifested. This was followed by what is known as a Serretyan eruption, which produced 'lava balloons' - bubbles of gas filled lava that would float to the oceans surface, and produce a fiery burst when the lava cracked and exposed superheated gas to oxygen. The lava rocks would then fall back to the ocean floor, building the underwater cinder cone further.

This continued for some months, and eventually dwindled down to a degassing phase. Many people had hoped/thought that the volcano would eventually create a brand new mini Canary Island, in what is called a Surtseyan eruption (where a submarine volcano breaks the water's surface to crate either an ephemeral island, much like what occurs regularly in the Marianas island/volcano chain, or a more permanent island like the recent eruption of Jebel Zubair in Yemen). It would have been a spectacular site for those on the island, and those that were watching the eruption webcam before the Spanish government shut it down (apparently running a webcam is really expensive! Yeah right...).

So I will again follow the goings on at La Restinga like I did before the eruption ended to bring you updates as they happen. This is a fun and suspenseful volcano for me to write about because it is such an unusual eruption, and it's occurring on an Island that didn't have much historical eruptive history. I always enjoy a good surprise. I'm not so sure the residents at La Restinga do however, as apparently they are beginning to loathe the attention that their volcano is getting, both from the reporters at El Hierro, and their own government.

Large Quake Swarm Under Herðubreið in Iceland

A large swarm of earthquakes is occurring just NE of the Askja caldera in Iceland. This began sometime yesterday and continues to the time of this writing (see below pic). It has recently been noted that Askja caldera was strangely ice free during the cold months, with the water still quite cold, yet unfrozen. Some theories about this pointed to possible underwater fumeroles, to chemical changes, and other theories, but as of yet nobody can fully explain why.

Picture graph from Iceland Meteorological Office


The current swarm of earthquakes is most likely related to magma dike intrusion. Currently I am unable to determine the depth of these quakes, but most quake swarms in Iceland are volcanic in nature, given that the entire land of Iceland is basically riding on top of a mantle plume, and is also smack-dab on the middle of a spreading ridge between the North American and European plates which are drifting away from each other.

The swarm's location is actually under a "tuya" named Herðubreið. A tuya is a volcano that most likely formed underneath a glacier, but never pierced the surface to produce an explosive eruption. There are many examples of tuyas in Iceland, Canada, Alaska, and other cold regions of the world where volcanism occurs. Most tuyas were formed during the ice age, as the ice back then was extremely thick and not even a volcanic eruption would have been able to break free of the ice. Herðubreið is theorized to have erupted in the last glacial ice period.

The nearby volcano, Askja, has also seen some recent possible activity (I covered the strange happenings at Askja in a previous post). The last time Askja erupted, according to the Smithsonian GVP, was in 1961 and produced lava flows from a fissure vent system near Öskjuvatn lake. The caldera forming event occurred in 1875, and was one of the largest eruptions seen in historical times by Iceland (with of course the exception of the famed Laki eruption that has been blamed for famine in Europe and the eventual catalyst for the French Revolution). An eruption from Askja today would likely consist of fissure fed lava flows with some minor explosions. The last report on activity at Askja included a satellite photo that seemed to show some very minor ash deposits near a crater on the rim of the lake, which may or may not be the result of an eruption (it could also be that it was ash was blown that direction from another deposit).

It is completely unknown at this time whether Herðubreið is an active volcano, however given the quake swarm, I would suspect that it is not completely dead. As Chaiten volcano, and Nabro volcano both recently proved, volcanoes long thought to be dead can spring back to life without warning. This is more than true in Iceland, so Herðubreið is a volcano that should be monitored in my opinion (and I am quite sure that it is now). There is no way to tell what type of eruption might occur at Herðubreið, but I would suspect that if any eruption occurs, it will be explosive. There are no towns or villages near Herðubreið as it is in one of the more remote and inhospitable locations in Iceland, so the danger level from pyroclastic flow or otherwise is quite low, however its location could pose a nuisance from ash to Europe.


*****UPDATE 5/18/2012*****

The quake swarm under Herðubreið is still ongoing at this time. Approximately 15+ quakes have occurred under the volcano within the last 48 hours.

Katla Reported To Be Melting Ice

A report from the Iceland Volcano and Earthquake Blog by Jon Frimann seems to suggest that Katla volcano in Iceland has been experiencing some ice melt and creating some jökulhlaups (glacier outburst floods). Jon suggests that a geologist who is close to the monitoring efforts on the volcano is recording harmonic tremor since April 28th, which suggests magma is on the move, and possibly making contact with the base of the glacier.

The months of April and May have so far been pretty quiet for the volcano when it comes to seismicity. While there have been many small earthquakes, they are few and far between. Tremor is not necessarily registered as an earthquake by seismometers, but is picked up by waveform monitors designed to listen to this type of tremor. Harmonic tremor typically denotes the movement of magma within a system, and is typically seen as a precursor to a potential eruption...

But then again, oftentimes (a recent figure from the USGS states something more like 90% of the time) harmonic tremor and magma intrusion doesn't lead to an eruption. Personally I would not go ringing the alarm bells yet on Katla volcano. If it was actually gearing up for an eruption, it is highly likely you would see many more rock fracturing earthquakes, followed by land swell indicated by GPS measurements. This would most likely take at least 1-2 weeks given the history of many Icelandic volcanoes, and would give us plenty of warning ahead of time.

Indeed, there has not been a recent eruption in Iceland that did not give off some fairly obvious warnings before the main event. The eruption of Eyjafjallajökull was preceded by GPS measurements that indicated the mountain was swelling outwardly, then harmonic tremor/volcanic quakes, ultimately resulting in the fissure eruption at Fimmvörduhals, and finally the main caldera eruption at the summit. Katla, despite its ongoing geothermal action, has not yet displayed the sequence of events that suggest an eruption is imminent.

Katla volcano will erupt in the future. Maybe even the very near future. But right now, I wouldn't hedge any bets on this being really soon. As the summer months warm Iceland, ice will most certainly melt, and it will be easier for geothermal heat to assist in this process. There will undoubtedly be adjustments to the earth's crust when the level of ice falls, and seismicity will probably pick up a little bit. For now, I (and I'm sure Jon Frimann) will be watching Katla a bit more closely. 

Japan's Iwo Jima (Ioto) Volcano Showing Signs of Activity

A report from Japan's Meteorological Agency indicates new activity at the famed WWII island of Iwo-Jima (Ioto). The report details that a new fumerole has opened, and there was water discoloration in the water near the island. Famed for its role in WWII when US forces were striking at Japan, most people don't realize it is actually an active volcano! While Iwo-Jima didn't have explosions during the war (without the aid of bombs and artillery), the island constantly fumes with acidic pools, fumeroles, and is prone to frequent, and small, phreatic eruptions.

The Smithsonian GVP characterizes Iwo-Jima here:

"Ioto (also known as Iwo-jima) in the central Volcano Islands portion of the Izu-Marianas arc lies within a 9-km-wide submarine caldera. Ioto, Iwo-jima, and Io-jima are among many transliterations of the name, which means "Sulfur Island;" the volcano is also known as Ogasawara Io-jima to distinguish it from several other "Sulfur Island" volcanoes in Japan. The triangular, low-elevation, 8-km-long island narrows toward its SW tip and has produced trachyandesitic and trachytic rocks that are more alkalic than those of other Izu-Marianas arc volcanoes. The island has undergone dramatic uplift for at least the past 700 years accompanying resurgent doming of the caldera. A shoreline landed upon by Captain Cook's surveying crew in 1779 is now 40 m above sea level. The Moto-yama plateau on the NE half of the island consists of submarine tuffs overlain by coral deposits and forms the island's high point. Many fumaroles are oriented along a NE-SW zone cutting through Moto-yama. Numerous historical phreatic eruptions, many from vents on the west and NW sides of the island, have accompanied the remarkable uplift."

The island rises from the seafloor to the surface due to the Pacific and Asian plate subduction zone, very close to the Marianas Trench, the deepest chasm on earth, where famed film director James Cameron just set a new depth record for an upcoming documentary on the trench. The Marianas Trench is a result of severe collision and subduction of the two plates and is prone to frequent submarine, and island volcanism, as well as very powerful earhquakes ranging up to 8.6 in magnitude (as far as we know). This is South of the fault that caused the devastating 9.0 earthquake in Japan last year which resulted in a large tsunami, and damaged the nuclear power plant at Fukushima.

Other volcanoes currently erupting in Japan include Sakura-jima, Kirishimayama (Shinmoedake), Miyake-jima, Suwanose-jima, Satsuma-Iojima, and Fukutoku-Oka-no-ba.

Japan, much like Indonesia, Russian Kamchatka, The West Coast of the USA, and the entire coast of South America, is part of the so-called Pacific Ring of Fire, and is quite prone to earthquakes and frequent volcanic eruptions. Most eruptions are fairly benign, and Japan has a large appetite for geothermal energy, and volcanic hot springs which the locals consider great medicine for skin ailments, and skin health. Locals love to use the hot water, and fine ash for exfoliation, and relaxation, and the volcanic resort towns are world renowned for their innovative use of what most people consider to be a dangerous and destructive force... but when your culture is as old as some of the volcanoes themselves... well, you either adapt or you don't!

A follow up also on the purported activity at Japan's Mt Fuji, which I touched on a while back. NO new info, video, photos, or anything of the sort has confirmed the news report from Japan about a "row of new craters" on the eastern flank, and recent satellite photography did not reveal these features on the mountain. I suspect that someone was rather mistaken, and wished to hype up the possibility of the eruption. In my previous blog post on Mt. Fuji, I pointed out that I was highly skeptical of the possibility of eruption, due to Fuji's worldwide fame, and the swiftness at which social media can cover such an event. Fuji is not an inconspicuous volcano, and I assume if there was ANY activity, it would be huge news quite fast.

New Info On Yellowstone Suggests "Super Eruption" Was Two Smaller Eruptions

Yellowstone volcano has long thought to have had a large super eruption over 2 million years ago, but new evidence is suggesting that while 2 million years ago Yellowstone DID erupt with a VEI 7 or 8 eruption, it was not as big as once thought, and was followed 6,000 years later by a smaller eruption. The result was an ash layer that appeared to be one layer but was actually two. This suggests that Yellowstone is NOT as powerful as once thought, but is more active.

The study revealed that the Island Park Caldera is actually much more active than previously thought, and the new information might assist scientists in better predicting an eruption from Yellowstone, given that the timeline has now changed. The last magmatic eruption in the Yellowstone caldera was some 70,000 years ago, and an episode of phreatic eruptions that created a 5km wide crater (now Yellowstone Lake). 

Scientists were using a new "Rock Clock" method to determine the ages of ash and rock layers within the Huckleberry Ridge, and were surprised at the data they found. The data suggests that Yellowstone's explosive eruptions were around 12 percent weaker than previously thought, but smaller eruptions are actually more numerous. The last eruptive activity of any kind in Yellowstone occurred somewhere around 1350BC (give or take around 200 years), and was limited to hydrothermal eruptions.

Knowing when, or how, Yellowstone might erupt in the future is one of volcanology's biggest challenges, given the impact an eruption from Yellowstone might have. But the new data seems to shrink the idea that Yellowstone is capable of a world-ending eruption (one thing I highly disagree with most scientists about is that any event on earth is capable of wiping out 'all life'... life did not simply get wiped out and reappear on the planet, there are always survivors). Indeed, the new data seems to suggest that Yellowstone is not capable of "blotting out the sun worldwide", but is still a very dangerous volcano to anyone within about 100KM.

This is good news for anyone who was worried that Yellowstone could be a 'world ender', and probably bad news for anyone who wants to scare people into doomsday nonsense for the tabloids. An eruption from Yellowstone today would likely be much weaker than previous eruptions, given that as far as anyone knows, no new magma has been introduced into the Yellowstone system for a very long time. Scientists theorize that the current magma chamber consists of partially cooled magma known as 'crystal mush', and any eruption would likely result from water flashing into steam when it seeps into hot rock (a phreatic eruption). These types of eruptions are short lived, and very rarely pose a threat outside of 1km, but anything is possible.

In any case, this new info will definitely be helpful to understanding further the history and potential of the Yellowstone caldera.

Alaska's Mt. Iliamna Volcano Rumbles Away

The heightened seismicity at Alaska's mt. Iliamna continues, and today the seismicity is stronger than it has been. At around 6am UTC seismicity increased and is ongoing at this time. This probably indicates further intrusion as the seismicity does appear to be harmonic tremor. Mt. Iliamna has not erupted in historical time, but the mountain displays vigorous fumeroles at the summit and flank. A previous visit by AVO scientists revealed heightened temperatures and gas emissions from the fumeroles, but they were quick to point out that the current unrest is similar to events in the 1990's when magma dike intrusion occurred, but did not lead to an eruption.

Live webicorder of Iliamna seismicity from AVO.

However the current unrest at the volcano is strong compared to previous events, and has now been underway for well over a month or so. It is my guess that intrusion is definitely taking place. Whether or not this actually leads to an eruption remains to be seen, but all the indicators are there.

Live image via AVO webcam of Mt. Iliamna

An eruption at Iliamna would most likely start off explosive, most likely phreatic eruptions. Phreatic eruptions occur when melt water comes into contact with a subterranean heat source like a magma chamber or very hot rock. This results in water flashing into steam and creating a steam driven explosion. Once this occurs, it can release pressure holding back the magma, and would likely enter a dome building phase. Of course, this is speculation because we've never seen the volcano erupt in historical time, and the structure of the volcano is highly eroded by glaciation.

Currently the visual indicators from Iliamna (via webcam) show nothing unusual, but as is the case for volcanoes that haven't recently erupted, this can change suddenly at any time. Eyjafjallajökull in Iceland experienced a couple hundred years of dormancy until seismicity increased, and began with a small fissure eruption, and then a main event that caused a widespread ash cloud to strand passengers in Europe for weeks on end, causing economic hardship in the Eurozone, not to mention a lot of frustration.

Due to Iliamna's location on a heavily trafficked air route, an eruption would cause some travel disruptions if an ash cloud was produced. However, there is no threat to any human population due to its remoteness but ashfall would likely occur in some towns near the area (including the area where the webcam is placed!). Alaskans are no stranger to ash covered homes and cars, as two volcanoes, Cleveland and Augustine frequently erupt and produce fine ash.

As it stands right now, there is no imminent risk of eruption, just heightened temperature and seismicity. You would likely see a much more dramatic rise in harmonic tremor and larger, more frequent, and shallower quakes if the eruption was about to start or was underway. But the best indicator of all, of course, is the webcam and visual observations. Until then, Iliamna rumbles away, keeping us all guessing.

My Beef With a Wired.com Article [Opinion piece]

Recently I happened upon an interesting article (or rant) on Wired.com's Eruptions blog, where the author, Erik Clemetti had challenged readers to describe or otherwise link the technology that would be required to successfully predict an imminent volcanic eruption. You can find my comments in the comments section of the article, but I was immediately like one of those kids who KNOWS the answer to the question in any school class raising his hand "Pick me! Pick me!".

Recently I started looking into what it would take to predict a volcanic eruption. I had seen several National Geographic specials about volcanic eruption prediction, and the pains to which some scientists have gone to make this sort of method or technology a reality. Erik seems to believe that A) No progress has been made and B) that it never will be... Allow me to retort!

First of all, there are some VERY interesting technologies out there to which he might be unaware. One such technology involves using muons (or more specifically, muon detectors). In a recent project undertaken by Japanese scientists, it was shown that placing muon detectors in a 360 degree pattern around a volcano, you can construct a complete 3D image of the volcanoes magma chamber. This technology works by calculating the number of muons flowing through a point in this 3D space to reach its destination. Muons thankfully are formed by the cosmos, so you need no machine, no projector, no generator to produce muons. They fly from all vectors and angles, and continue on uninterrupted until they collide with something (usually something VERY dense like lead, rock, etc). The absence of resistance from the muons travels (ie, the more muons that hit a certain detector at a certain angle) indicates a weak resistance force. This in turn indicates a magma chamber, or void space. This data is then used to create an actual 3D image of the magma chamber... and let me say, I would be skeptical too if I didn't see the tech work on TV. It is now being used to map the chambers of both Mt Shasta in California, and Mt Vesuvius in Sicily.

There are also other very good tell-tale signs that an eruption could be about to occur. Harmonic tremor and long-period events (one in the same really) indicate rising magma underneath the surface. While a recent article about Santorini on MSNBC pointed out that scientists say "90% of the time, magma intrusion does not lead to an eruption", persistent harmonic tremor has preceeded a great many powerful eruptions, most notably (and why harmonic tremor is now considered to be a precursor to an eruption) with a Columbian volcano (Galeras) that erupted, killing many including the volcanologists at the summit), even after the volcanologists had warned that an eruption was imminent. This eruption WAS predicted, and the prediction was ignored.

However, all volcanoes are different. What worked at Galeras does not say, work at Mt Shasta, nor could the same exact method be applied to a great number of volcanoes int he world. Plainly speaking, volcanic eruptions could only be predicted by using specific methods for specific volcanoes, until the day that we have such technology that can predict magma currents in the mantle to the lithosphere with as much accuracy that we do with weather.

Currently, we can tell a volcano is getting ready to erupt by many factors, such as increased harmonic tremor (undetectable without instrumentation most of the time), increased fumerolic or hydrothermal emission, increased SO2 and CO2 emission (indicative of de-gassing magma), deformation (measured via GPS) of the volcano, or frequent volcanic tremors. Couple this with a muon scanner that can tell you if magma is in fact in the chamber... well you have yourself a volcano eruption predicting machine, at least giving you a few days notice before an eruption (speculation, yes, but I imagine quite clearly that this would be one hell of a comprehensive system!).

But do NOT count out human innovation. Using muons to map internal geological structures is not a new idea., and the technologies required to make such a method to predict eruptions might already be available, but simply have not been tied together into the proper medley of technologies so that they are useful to us. If I had to take a wild swing as to when these technologies might be available and in use, I would guess probably 10-20 years from now. It is simply only a matter of time, and innovators are only limited by their imaginations and the materials available. I don't see that being a particular challenge this day and age when open-source collaboration is on an upswing. Just look at the private space travel industry!

In any case, it is my onion that not only can we, as humans, eventually predict eruptions, but the technology is already well underway to do so. So, to the author of Wired, I do appreciate scientific skepticism, but you might want to catch up on the stuff that is already being invented. You might say that scientists are keeping secrets, but I had no trouble in finding information BY SCIENTISTS to the contrary.

What do you think? Post your links to neat geological tech below and let the debate begin! You can see the links to the muon scanners (by the scientists who invented and tested them on volcanoes) below!

http://indico.cern.ch/getFile.py/access?contribId=19&resId=1&materialId=paper&confId=51276 (link to CERN labs explanation of MUONS)

http://www.eri.u-tokyo.ac.jp/yaoki/2010JGR.pdf link to scientific paper by the tech's developers.

El Hierro Activity Still Apparent, Government Pretending It's Not There

The Spanish government at El Hierro is quickly trying to sweep the eruption under the rug. Even while Earthquake-report.com's Joke Volta continues to photograph clear evidence of underwater activity, underwater video showing degassing and small amounts of erupting lava, and even while seismographs continually record weak volcanic tremor, the government has insisted that the eruption is over. And to prove just how serious they are, they are lowing ALL alert levels, including near the eruption zone itself to "green".

This has a lot of people, especially the folks over there at Earthquake-report.com, scratching their heads as to why a government could actually be so careless. This whole eruption at El Hierro has been incredibly mismanaged by their tourism industry, and the government. Indeed the government has even stood in the way of actual scientific data on the eruption even being made public! Their stance has been one of fear, and thus far has crippled the economy of the small town of La Restinga, rather than helped it. From over cautious evacuations to cover ups, to the downright irresponsible LIFTING of the alert level, it seems the only people who know the truth were those that watched the web cams and hovered over the seismic data. And now the webcam is gone.

This has been a very odd volcano to report on, not because of its submarine eruption near a bustling tourist town, but because of the politicization of a volcanic eruption. It is a story that belongs in a bad volcano movie (Sorry Tommy Lee Jones!), not the real world.

Volcanic eruptions, when benign, and non-threatening as El Hierro is, typically should be a boon for communities and countries. Hawaii volcanoes national park in the US regularly draws tens to hundreds of thousands of visitors a year, all who want to see molten lava hit the ocean in giant explosions and witness the birth of new land. Iceland had an incredible surge in tourism when Eyjafjallajökull erupted in 2010. Italy's Etna volcano is famous worldwide for its frequent and spectacular paroxysms. And there are multiple volcanoes in South America such as Arenal, Poas, Tungurahua, and more that are regular draws for tourists and scientists alike...

So why did the El Hierro situation go the exact opposite way? First, the government tried to sweep it under the rug. Then it admitted something was going on, and it overreacted and evacuated large portions of the island, and also TOLD tourists not to show up. After that, they regularly butted heads with scientists, telling them what they could and could not make public about a geological event, sewing distrust. And if you are a regular reader of Earthquake-report.com and Joke Volta's adventures there, you'd know that she is now under pressure to "shut up" by the locals who are starting to blame her and Earthquake-report.com for the lack of tourists (or scaring them away) because of her efforts to document every day of the eruption (which is what GOOD volcanologists DO!).

This is kind of spooky. Why on earth would the Spanish government want to cover up an eruption that is CLEARLY ongoing? Its quite strange and disturbing to think that a government can be so incompetent in regards to a natural geological event. It could have gone so differently for the island of El Hierro and the town of la Restinga. They could have had thousands of sight seers, and busy cafe's, but the government instead scared everyone, and tried to un-do their mistake. Now it's simply a mess, and nobody is very happy about it. 

Island of Fogo Is Having Volcanic Tremor

The island of Fogo looks like something out of a sci fi fantasy movie. A massive island inlayed by a large caldera, with a spire-like volcanic cone in the center that looms high over the tropical landscape. Below the peak of Fogo (Pico do Fogo) lies a paved over, barren landscape, surprisingly home to houses and facilities built atop fresh lava flows. Fogo was one of the first volcanoes that fascinated me, given its striking appearance and remote location. To visit this volcano, for me, would be quite a sight.

Fogo is not a very well-known volcano, but it is capable of some serious eruptions. Indeed the original caldera forming event likely created tsunamis and landslides that would have hit the neighboring islands, and maybe even the African West Coast. The island itself is dotted with cinder cones young and old on its flanks, suggesting a very active life cycle as a volcano. Now, the volcano is getting seismic equipment installed on it, and already, results are coming in pointing to volcanic tremor, and small volcanic earthquakes. Fogo is waking up.  (or was it ever truly asleep?).

Fogo's last eruption occurred in 1995, when a small cinder cone was erupted on the WSW flank of the Fogo peak. This eruption started off as a fissure, and gradually built a cone, and produced slow moving pahoehoe lava flows that pooled at the base of the mountain.

Picture of the 1995 eruption of Fogo, from Smithsonian Global Volcanism Program website. Photo by Dick Moore, 1995 (U.S. Geological Survey)

The Smithsonian GVP Characterizes Fogo here:

"The massive 9-km-wide, horseshoe-shaped Cha caldera truncates the summit of Fogo stratovolcano, the most prominent in the Cape Verde islands. An ash plume (center) rises from the western flank of a steep-sided central cone, Pico, that rises more than 1 km above the caldera floor to form the 2829 m high point of the island. Pico, which is capped by a 500-m-wide, 150-m-deep summit crater, was apparently in almost continuous activity from the time of Portuguese settlement in 1500 AD until about 1760."

An eruption of Fogo today would likely be characterized by another small cinder cone building event, or possibly a larger more explosive event from the summit cone (which has not recently erupted historically speaking), which could be capable of strombolian type, or Hawaiian type eruptions. Flank eruptions on the West side of Fogo were considered to be Holocene, but most eruptions have occurred on the East side of the caldera rim recently. The West side of the island is heavily vegetated and is probably not at risk.

The Portuguese islands of the Cape Verde chain are all volcanoes, or have been volcanoes at one point in time or another (some are very old). Installation of more monitoring equipment is exciting news for some of us who long for a global volcanic monitoring network, and certainly for the scientists who will be poring over reams of seismic data. Every year, volcano monitoring gets better and better, and disasters and deaths are able to be more easily averted due to good early warning systems. It is my thought that within 10-20 years of today, we will actually be able to routinely scan a volcanoes magma reserves to determine whether an eruption is imminent, and when it might occur. The new muon-based mapping technology developed in Japan is a major step forward, and is currently being tested on volcanoes such as Vesuvius, and Fuji. 

If anything new develops on Fogo, you'll read about it here!

Mexico Raises Popocatepetl Alert Level

One of Mexico's most active volcanoes, Popocatepetl (Smoking Mountain) is showing signs of increased unrest, prompting the local government to raise the alert level to 3 (out of a max of 4), and instituting an exclusion zone of up to 7 miles from the summit. After 40 minutes of volcanic tremor, and some minor exhalations of ash and steam, the volcanoes activity has been steadily increasing over the past couple of days. Popocatepetl's last major eruption in 2000 caused widespread ashfall, but no fatalities.

The volcano, easily seen from Mexico City, is one of Mexico's tallest volcanoes, reaching heights of 17,802 feet at the summit (this does vary as lava domes are made, collapse, and the volcano swells or subsides). It has a long history of explosive eruptions, some of which were plinian in nature (shooting high volumes of ash, lava, and gas high into the atmosphere). The last plinian eruption occurred somewhere around 800AD. The volcano lately has only had short bursts of ash and steam.

The reason for raising the alert level is the amount of time the tremor was sustained. A 40 minute long intense volcanic tremor that was heard and felt by locals means a swift injection of magma into the chamber has probably occurred. This could indicate that "Popo" is gearing up for a large eruption, probably on the scale of its 2000 show. It is still too early to tell if Popo will put on a major eruptive display, or if it will sit and seethe. Incandescence was observed at the summit crater overnight, indicating either a building lava dome, or lava effusion at the summit. This is actually typical of the volcano, which doesn't go long between eruptive episodes, minor or major.

Mexico has suffered several large quakes in the last month, which leads to speculation about the effects of earthquakes on volcanic systems. While the quakes were large, they were actually hundreds of miles away from the actual volcano, so earthquakes affecting this volcanic system from that distance is pretty unlikely.... not impossible, but very unlikely.

Shallow Quake Swarm at Joshua Tree East Of Palm Springs

There is absolutely nothing, and no information on this on the web, so I thought I might bring it into the light for scrutiny. There is a continuing quake swarm occurring in Joshua Tree National Park, about 35 miles East of Palm Springs, CA that is beginning to look quite intriguing. The range of depth is from 8km to less than 1km, and about 2 quakes are occurring every hour. The strongest quakes were two mag 3.5 tremblors that were lightly felt in Palm Springs and surrounding towns.

The area is definitely part of the Rio Grande rift, a series of spreading faults that resemble "stretch marks" on the Western USA's topography. This rift, much like the African Rift Valley (although nowhere near as active volcanically) is home to a great many volcanic features. This particular area is parallel to the San Andreas fault line, the most active fault line in the USA.

The swarm is concentrated below an ancient volcanic mountain, and has been very consistent in its locations. All quakes are occurring within a mile of each other. This does look a bit like a deep magma dike intrusion, but it is definitely still way to soon to tell what is going on. Dike intrusions into the crust happen all the time, and most times they never result in any surface volcanic activity.

A Google Earth Snapshot with USGS real-time quake overlay showing the location and number of quakes in the swarm. The largest quake occurred yesterday and was a mag. 3.5, with a matching 3.5 quake occurring today (4/4/2012).

While this probably is a magma intrusion into the crust, there are other possibilities such as these being a precursor (foreshock) to a larger quake in the future, or a very small tectonic slippage. In any case, this swarm is intriguing not just because of its location, but because of the number of quakes occurring within the area. As this is occurring along the San Andreas fault however, it is very hard to tell whether or not this is purely tectonic, or if there is an intrusion taking place.

As this is, to my knowledge, the only article about these quakes so far, I will withhold further speculation about what is going on here until (or if) the USGS comments on the quakes, or if they become newsworthy. It is simply impossible to tell from available data whether or not these events will be significant, or insignificant, but as always I will keep an eye on these interesting occurrences, and post updates if anything changes. For now, keep your eyes peeled East of Palm Springs (and I would avoid going spelunking out there any time soon!).

*****UPDATE 4/9/12*****

The quake swarm is continuing with now more than 50 quakes striking the region. The swarm is very much beginning to look like a dike intrusion, at least on the Google Earth USGS plugin. It is quite similar to the precursors at El Hierro, deep quakes, numerous, and rising in depth. Still, nobody is reporting on this, so I am at the mercy of my own assumptions, which I will keep quiet for now, but this is definitely an area to keep an eye on for a while, at least until USGS takes notice. If anything further develops, I will update this post again.

Earthquake Swarm and Possible Dike Intrusion at Krísuvík Volcano in Iceland

There is not a whole lot going on in the world in respect to new eruptions or volcanoes at this moment, however Iceland is always fascinating to watch. Today there was a swarm of quakes just SW of the Kleifarvatn lake, just south of the epicenter of Krísuvík volcano. The quakes were shallow, weak, and numerous, but the area is highly active, much like most of Iceland. Most of the quakes registered below a 1.0 magnitude, but were clearly seen on the many Icelandic seismic sensors. The are is home to many thermal vents, as well as hot springs, fumeroles, and fissures.

The last known eruption of Krísuvík volcano was in the 14th century (the 1500's). A few eruptions have taken place at this location after Iceland was settled, but nothing in recent times. It is probable that this swarm will not lead to an eruption any time soon, but Iceland sits on a spreading fault, so it is not a matter of if, but when this volcano will erupt again.

There are several volcanoes in Iceland that are expected to erupt at least within the next 10 years. Those are Katla, Askja, Grimsvötn (or Grimsfjall, Grimsnes), Hekla, and the Reykjanes Ridge, all of which show heightened seismic and thermal activity. However for most of these volcanoes, it is normal to display some kind of activity, and no eruption for any of these, save probably Katla and Hekla, are certain.

Icelands last major eruptions were from Eyjafjallajökull, and Grimsvötn. The Grimsvötn eruption, while spectacular to watch, was nowhere near as big a deal as the Eyjafjallajökull eruption which caused widespread economic damage due to flights to and from Europe being grounded for weeks because of the ash cloud it produced. The ash from Grimsvötn is much more coarse and larger grained than the very fine and powdery ash produced by the Eyjafjallajökull eruption, and thus fell to the earth quickly and did not get picked up by the jet stream.

The activity at Krísuvík can be attributed to a few causes. For one, Iceland is one of the worlds largest users of hydrothermal/geothermal energy, and regularly injects water into hot rocks to produce steam. This does sometimes cause swarms of quakes to occur, and it is rather hard to tell whether or not this could be related, but as the quakes happened on an active spreading fault, I suspect this is not the case, rather a small magma dike intrusion probably occurred.

Around the world most dormant volcanoes are sleeping or slowly rumbling away. Mt Etna did display some nice activity this weekend, but other than Etna's fireworks show, most active volcanoes showed relatively little activity during the month. Not good for us volcano bloggers out there to tell a story, but hey, the Earth does what it wants on its own time with little concern for my Google money! Hopefully this post is at least a good diversion! I'll post more as it occurs!

Another 6.3 Quake Hits Mexico

A magnitude 6.3 quake struck the Oaxaca region of Mexico today, near the area where the large mag 7.6 quake hit a couple weeks ago. This is the largest aftershock thus far from the 7.6 tremblor. Housing and property were damaged by the large quake, however injuries and fatalities were thankfully very low due to citizens being well prepared for evacuating. Mexico, like the West Coast of the US, is part of the Pacific Ring of Fire, an arc of subduction faults and volcanoes spanning the rim of the Pacific plate.

The quake was centered in the Western corner of the state of Oaxaca, approximately 2 miles away from the epicenter of the 7.6 quake. The quake was felt as far away as Mexico City due to the composition of the earths crust (a mix of clay sediments, and volcanic ash), which is a good conductor for seismic waves.

No volcanic unrest has been associated with these quakes. Several rumors were circulated that Popocatepetl might have been 'disturbed' by the shaking, however the volcano continues to act normally, only occasionally puffing our steam, or small amounts of ash.

Mexico is very familiar with earthquakes and volcanic eruptions. Central Mexico is home to thousands of cinder cones, vents, stratovolcanoes, and calderas. Popocatepetl is Mexico's most active volcano, having erupted fairly regularly in historical time.

The current seismicity is associated with the collision and subduction of the Pacific Plate and the North American plate, and is not volcanically related. Some quakes can and do disturb volcanoes, and can destabilize magma chambers, but most volcanoes in Mexico are long dormant, or too far from the quake epicenter to be affected in any serious way, so there is probably no risk of heightened volcanic activity as a result of the recent quakes.

*****UPDATE*****
The quake was downgraded to a 6.0 later by USGS. No reports of damage or injuries have been made apparent.

New Info On Bolivian Volcano Uturuncu Indicates Uplift Is New

The recently "awakened" supervolcano in Bolivia, Uturuncu, may have actually awakened just recently, according to new data. The data suggests that the volcano began re-inflating quite recently. In fact, a report on VolcanoDiscovery.com suggests that the uplift began as recently as 1992, according to sediment uplift data. This suggests that not only is Uturuncu awakening, it suggests that Uturuncu is quickly building up its massive magma reservoir and may actually lead to activity in the area... and at the worst case, a caldera forming super eruption.

Uturuncu has never erupted in historical time. Indeed data suggests it has not erupted for over 200,000 or more years, making it an enigma. The current uplift of approximately 1-2cm per year over a 70km wide radius from the central volcano, suggests mathematically a magma intrusion of approximately 1 cubic meter per second, from a source approximately 14km in depth, filling a much shallower 3km deep magma chamber. To keep things in perspective, this is the same approximate distance of the Yellowstone caldera's magma chamber depth.

The difference between Yellowstone and Uturuncu however is vast. Yellowstone displays far more fumerolic and hydrothermal activity, however as far as we know, it has always done so in our history. Uturuncu has been quiet during the same period of time, until now. On average, 2.6 earthquakes per day are recorded at the volcano, sometimes spiking to more than 14 quakes per day. Harmonic tremor is present at Uturuncu, unlike Yellowstone, which geologists say has not had much magma intrusion or inflation. Indeed, scientists theorize that a lot of the uplift and subsidence at the Yellowstone caldera is related to gas and water, not magma.

Uturuncu getting a fresh injection of magma after such a long time is something new to scientists. Most volcanoes that are dormant for this long tend not to erupt again... or so we thought. Many volcanoes with long periods of dormancy-- some we thought were extinct-- have recently 'activated' and erupted with incredible force. Nabro volcano in Africa, and Chaiten volcano in Chile, were both thought to be long dormant, or completely extinct. All it took for these volcanoes to "wake up" were some rather large quakes and a quick injection of fresh magma. Chaiten and Nabro volcano are still active.

This new data on Uturuncu is both fascinating and terrifying, although scientists caution not to worry or start planning your doomsday bunker just yet-- it can take thousands of years for Uturuncu's magma chamber to inflate to the point where it will actually erupt... PLENTY of time to plan for a disaster (and who knows, in 1,000+ years we might have technology that can "deflate" a volcano and prevent it from erupting catastrophically... purely in the sci-fi realm at the moment, but I don't put it past us to innovate our way out of a super eruption in the future).

There is always, however, the possibility that the volcano has simply tapped into a vast source, and will erupt without warning. It has happened to much smaller volcanoes, and rest assured it can happen to any volcano. There is truthfully no point in worrying about a super eruption from Uturuncu. Surface activity is nominal, with the same fumeroles and hot springs active that have been for thousands of years. No new surface activity like steaming, fissure cracks, etc have been observed at the site, so for now at least, there is nothing to worry about in the near-future.

Uturuncu is surrounded by the worlds largest collection of supervolcanic calderas. Millions of years ago, Bolivia was host to some of the worlds most violent eruptions, and Uturuncu is just ONE large volcano out of hundreds in the area. The area is poorly studied, so it would not surprise me in the least to learn there are several volcanoes out there that are inflating without our knowledge. Pure speculation though, and I do try to stay away from that. In any case, this data will be used to refine our understanding of supervolcanoes, and give scientists and opportunity to track the inflation of what was thought to be a long-dead mountain.

AVO Lowers Alert For Cleveland Volcano To "Yellow"

The slowly erupting stratovolcano in Alaska, Mt. Cleveland, has been lowered to level "Yellow/Advisory" with AVO geologists stating "No further explosions have been detected at Cleveland since March 13, and we have no evidence that lava-dome growth has renewed since then. Therefore, we are lowering the Aviation Color Code to YELLOW and the Volcano Alert Level to ADVISORY."

Mt. Cleveland had been experiencing slow lava dome growth for the better part of a year, with a couple of collapses and small explosions, but nothing in the range of some of its past activities. Cleveland volcano has in the past erupted quite violently creating large plumes of ash some 30,000 feet high, but this episode was slow, effusive, and really not a huge deal.

The island itself is uninhabited, and far from any populated areas. It is however the only volcano of the Aleutian arc with a fatality (one) on its record, from an eruption in 1944. Mostly the volcano has annoyingly deposited ash  on nearby towns during large eruptions, or caused air traffic diversions.

The other volcano showing signs of unrest in Alaska is Mt. Iliamna which has undergone a series of magmatic quakes, thought to be related to dike intrusion. A recent expedition by AVO scientists to this volcano has revealed an increase in gas emissions (SO2, and CO2), and vigorous steaming/fumerole action. AVOstates that this does not mean an eruption is imminent and they saw no signs of rockfall, or avalanches in the area. However, they did seem to note some slight deformation in a glacier, but they were unable to attribute that solely to the volcano.

Magnitude 7.6 Quake Strikes Mexico [UPDATED]

A Magnitude 7.6 earthquake occurred in Southern Mexico today, with the epicenter between Guerrero and Oaxaca. The quake was felt as far North as mexico City, which is approximately 200 miles from the epicenter. Shaking was extremely violent at the epicenter, and for a radius of around 100 miles.

No current reports of damages or injuries, however news is slow to come out of the region, and there will likely be many follow up reports on this.

*****UPDATE*****

As expected, reports have started to flood in from Mexico (keep in mind, I wrote this post the second the quake popped up on my Google Earth USGS plugin), and the damage is striking.

Many hundreds if not thousands of homes have been damaged or destroyed. 11 people have so far been confirmed dead, which is actually very good considering the magnitude of the quake and the area that it struck. This number will likely rise however, but at this time it does not appear that as many people were hurt or killed. In 1985, a very large and shallow 8.0 quake hit Mexico City, killing up to 10,000 of its citizens.

The quakes in central and Southern Mexico are especially damaging due to the composition of the ground... volcanic ash and clay deposits. These materials conduct seismic waves with ease, and when an earthquake hits, can liquify the ground, sinking buildings. This liquifaction effect was very apparent in video from Japan when the 9.0 quake and tsunami (oh yes, throw int hat nuclear disaster at Fukushima too...) struck. One video showed black water spouting out of sidewalks and lawns.

The 7.6 (some news organizations are incorrectly reporting the magnitude as 7.9) quake has spawned many aftershocks. At this point in time, 17 aftershocks, all ranging from 4.1-5.3, have struck near the area of the initial quake. As a Southern Californian, used to many quakes, I can say from firsthand experience that a 5.0 quake is still no joke, especially if you're near the epicenter. I was present in San Diego when a magnitude 7.2 quake hit Mexico near Mexicali/El Centro (I happened to be camping not 20 miles from the epicenter that day, and had planned to explore the mud caves out there... thankfully my friends and I couldn't find them, or we might have been the ONLY casualties of that quake on the US side of the border!!), and saw the ground ripple. Where I was when the quake actually hit was near the coast, and USGS says that would have felt like a mild 6.0 quake.... nothing mild about it.

Thankfully, Southern California has great construction codes that allow our buildings to nearly shrug off anything up to an 8.0... anything larger would be pushing it. The same is not true in Mexico, which is a very poor country. Most buildings are built without strict adherence to earthquake code, are very old, or are built illegally, making earthquakes that much more dangerous in the region.

Aftershocks and other quakes will happen in the area for a while. The 7.2 quake of Easter 2010 has left the entire Southern California/Northern Baja California fault system in a state of perpetual flux, generating tens of small quakes every day. In another blog post I talk about the recent spate of activity at the Salton Sea, which looks like magma dike intrusion, which began to occur after the quake. Not many people know it, but the entire area from the Salton Sea to Cerro Prieto is a spreading fault, and will erupt in the future *(the newly minted California Volcano Observatory lists the area as a high threat for future eruptions).

Anyhow, welcome to the Pacific Ring of Fire. Subduction quakes are simply a fact of life out here!

AVO Sends Team To Mt. Iliamna To Check Gas/Temps [UPDATED]

AVO scientists have sent a team of geologists on a fly-by mission to Mt. Iliamna, Alaska's restive volcano that has been showing signs of activity since January. The apparently successful mission to go to the volcano to check gas levels and temperatures on the summit fumeroles has produced results, and AVO is expected to release their findings today on their website (http://avo.alaska.edu).

Mt. Iliamna has been experiencing heightened levels of seismicity for some time, but recently in January there were some rather intense quake swarms, at very shallow depths (some swarms were less than 1km underneath the surface), with some quakes registering up to magnitude 3.7. AVO has subsequently raised the alert level to "Yellow"(watch), and has actually directed one of their webcams to watch the volcano visually (below picture).

Live webcam snapshot from AVO.alaska.edu

Iliamna does not have a record of historical eruptions, however AVO and GVP state that it's last eruption was approximately 140-200 years ago. Active fumeroles exist at the summit, and the last activity in 1996 was similar to the current level of activity.The 1996 quake swarms were also thought to be magma dike intrusion, much like today's swarms. AVO scientists stress that this does NOT mean there will be an eruption, however I would wager that with several dike intrusions, the magma will try to find some way to the surface. In my opinion, a minor eruption is very likely at Iliamna in the coming months or years.

It is anyone's guess as to what characteristics an eruption at Iliamna would take on. It is a stratovolcano, and part of a subduction zone, so like most Aleutian and Alaskan volcanoes, it would likely be an explosive event followed by dome growth and thick lava effusion. For now, AVO is monitoring the volcano, and so am I!

*****UPDATE 3/20/2012*****

AVO has completed their initial survey of Iliamna volcano and released the following news:

"Seismicity at Iliamna Volcano remains above background. Data from Saturday's gas and observation flight indicate that the volcano is emitting elevated levels of sulfur dioxide and carbon dioxide, consistent with a magmatic source. It is not know, however, if this is a newly intruded magma, or whether new pathways for gas from preexisting magma have caused the increased gas flux. The amount of gas being emitted is broadly similar to levels seen in 1996-1997, when a likely magmatic intrusion but no eruption occurred at the volcano.

Observers on the flight saw vigorous and plentiful fumaroles (gas vents) at the volcano's summit, consistent with the elevated gas emissions. No obvious signs of recent rockfall, large areas of newly exposed bedrock, or unusual disturbance of the glacial ice were observed. Some deformation of the ice at the headwall of the Red Glacier on the east side of the summit was seen, but it is not clear this is related to the current volcanic unrest; avalanching of the glacier is common on this very steep area and was last seen in 2008."

So it does appear at this time that activity has at least increased visually, indicating rising temperatures from deep below. Iliamna is officially a volcano to keep an eye on!

Katla Volcano Has Another Quake Swarm

Katla volcano in Iceland is having another quake swarm today, during what some say is supposed to be a quiet time geologically for Iceland, during the harsh Winter months. Seismicity is elevated today at the Mýrdalsjökull glacier, with some quakes even occurring at the neighboring Eyjafjallajökull volcano. Eleven tremblors struck within the Katla caldera within the last 24 hours. As I write this, the swarm is ongoing. Most of the quakes except for two were below 2.0 in magnitude, with the largest being a 2.5. Many smaller >1.0 quakes occurred.

This again is probable dike intrusion into Katla, which has seen elevated seismicity and geothermal activity since its very small eruptive event last year (which produced a glacier outburst flood, and caused minor damage to bridges and roads). 

Image from Iceland Met Office showing today's quakes at Katla/Mýrdalsjökull 

Katla has been seismically active for months, with most scientists expecting an eruption soon.When is impossible to say, however this will likely be larger than last time due to the amount of magma intruded into the system. Swarms have occurred at the volcano at least a few times in any given month since June of 2011, but so far has not resulted in a large eruptive event like its neighbor Eyjafjallajökull, who's eruption in April 2010 produced a large ash cloud, carried by the jet stream, and stranded millions of travelers in Europe as airliners were grounded due to ash concerns.

Europeans fear a repeat of this event should Katla erupt, however it is anyone's guess whether an ash cloud from Katla would even follow the same pattern. It is entirely possible that the ash cloud going go East, and give the United States East Coast a taste of the headaches that Europeans suffered. Or the ash could simply blow South, into the ocean, harming no one. In any case, Katla rumbles on, gearing up for its inevitable show. 

Italy's Mt Etna Has 4th Eruption of 2012

Mt.Etna has been stealing the show lately with spectacular eruptions (called paroxysms) that have been very frequent this year. Yesterday Etna erupted producing lava fountains, and light ashfall. This is the 4th paroxysmal event of 2012, and part of Etna's regular pattern of eruptions.

Etna is (arguably) the world's most active volcano, aside from possibly Kilauea in Hawaii (although Kilauea has only been erupting continuously since 1983, Etna has been active for far longer), and is host to frequent lava flows and explosive activity. Etna has seen more activity lately, and the webcam is rather fun to watch, especially if you like to watch great lava shows.

While the eruptions do not pose a threat to any towns or population centers, Etna is a large and sprawling shield volcano, and has erupted far outside the summit previously, producing pyroclastic cinder cones, fissures, and more. The potential for an eruption on its lower flanks is an ever present threat, however this has not happened in a very long time.

Lamongan Volcano In Indonesia Showing Signs of Brewing Eruption

Lamongan Volcano in Indonesia is showing signs that it may soon erupt. The normal background seismicity of a few quakes a month has skyrocketed to more than 150 events per week, prompting the Indonesian government to raise the alert level to 2 out of 4. A 1km radial exclusion zone from the summit is now in place as authorities attempt to prepare for an eruption from this volcano.

Lamongan was last active during the end of the 19th century and has been relatively quiet ever since.The landscape surrounding the volcano is dotted with numerous large maars (explosion craters created by groundwater coming into contact with hot magma or partially molten rock), cinder cones, and fissure vents.While not particularly active during human habitation, the evidence is all around for an active history spanning hundreds of thousands of years.