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.

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.

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.

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.

Alaska's Cleveland Volcano Back To Alert Level "Orange"

AVO has again raised the alert level at Cleveland volcano due to the resurgence of yet another lava dome at the summit. Two have been emplaced slowly, and each time the dome has either exploded or collapsed in two very minor eruptions. The slowly erupting volcano has been going back and forth between "Yellow" and "Orange" aviation codes during the recent months. Typically after the dome collapses, AVO has lowered the alert level thinking that the volcano may have stopped erupting, but this has turned out not to be the case.

Cleveland volcano has been erupting for around a year, with an initial lava dome emplaced at the summit crater that reached a diameter of approximately 160M. This dome was destroyed when the volcano had an ash producing eruption. A smaller dome was extruded into the crater, and also subsequently destroyed. The current situation is another lava dome is now being built, however the current dome has not been measured.

This slowly erupting volcano can escalate the eruptive activity with little to no warning, and Cleveland was actually responsible for the only death ever from an Aleutian volcano. The "Orange" alert does not reflect the slow eruption, but its potential to enter into explosive phases at a moment's notice. The Aleutian arc is a very popular sky route for many airlines going to and from Asia to North America, and given an incident with Redoubt volcano in which a plane nearly crashed due to ash being sucked into its engines, AVO takes no chances with the safety of travelers.

For now the volcano continues to slowly seethe and push out the viscous lava into the crater, repeatedly making and destroying its lava dome. It is possible that new magma is pushing up older, cooler magma to the surface, and this is just the "cork in the bottle" so-to-speak. As AVO states, it is certainly possible for this volcano to change eruption characteristics at any moment. Good thing that this volcano is in an area of the world that is nearly uninhabited!

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.

Government Officials Declare El Hierro Eruption Over... When It's Not

Apparently under public pressure to declare the resort island of El Hierro "open for business", Government officials in Spain/Canary Islands have declared the alert level at El Hierro be lowered to "green" (the level before the eruption). This occurs as INVOLCAN conducted an R.O.V. mission to the crater, and discovered that yes, in fact, the volcano is still very much erupting, although the characteristics of the eruption has changed. While there is no vigorous "jacuzzi" on the surface, below the water a lot is still going on.

The eruption is very much like the submarine eruptions produced by Loihi on the southern end of the Big Island of Hawaii. Pillow lavas are being extruded onto the sea floor, and continue to do so.

So was this declaration of "green" a politically motivated, and non scientific maneuver? You betcha. I don't think there would be one actual scientist studying this volcano that would say the eruption has ended. If that were true... well obviously lava would not be flowing, now would it?

So the eruption actually continues at this time. The type of eruption this has ended up as is not a Surtseyan eruption, as many people thought might occur, rather the eruption type is called an "Serretyan" type eruption. Earthquake-report.com has a lot more info on this, but I thought I'd share their great image they published on what characterizes a Serretyan eruption.

Descriptive image of a Serretyan eruption, from Earthquake-report.com

El Hierro is a difficult volcano to analyze and monitor as it has turned out to be very unique in its eruption characteristics. Many thought a pyroclastic cone would develop on the island, or that an eruption would ensue in the El Golfo bay (probably because it is shaped like a caldera, even though its just a massive collapse scarp), which actually still has the potential to happen, but it ended up being a very benign submarine eruption that never reached the water's surface. While not an exciting eruption to watch, the concept of this volcano is pretty intriguing, and of great scientific interest, as this volcano is displaying some mechanics that we don't often get to witness.

In any case, if anything interesting happens at El Hierro, I'll be sure to post about it! I simply wanted to share this with the readers to notify that the eruption is still going on, despite what governments may say!

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. 

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.

6.9 Magnitude Quake Strikes Off Japan Coast

A 6.9 magnitude earthquake struck off the coast of Honshu, Japan near the location of last year's deadly quake and tsunami. Six large aftershocks have occurred so far in at or near the epicenter ranging from 6.1 down to 4.6.  More quakes shook the Tokyo region later in the day. The quakes off the coast of Honshu generated a small 8-inch high tsunami. No damage was reported.

This series of quakes (while rather common in the region now) comes almost exactly one year (plus a few days) after the devastating magnitude 9.0 magnitude quake.The 9.0 mega-quake damaged the Fukushima nuclear plant resulting in a meltdown and widespread radiation which has devastated a large portion of Japan and has made the land uninhabitable. Further damage was visited on Japan by a 30-40ft high tsunami wave that destroyed large portions of Japans coastal cities.

The subducting plate is now in nearly continuous motion since that event, with large quakes being a fairly regular and almost daily occurrence. it is regular for magnitude 5.0 and up quakes to hit the region along the subducting plate.

Japanese scientists are also closely watching the restive Mt.Fuji for further signs of unrest following a series of quakes in the area, and recent (very unclear) reports of "a new crater" on the NE side of Fuji (however this was NEVER confirmed), as well as reports of new fumeroles.NONE of these reports are confirmed, and translation from Japanese to English via Google translate is worthless. Volcano-report.com has however picked up the story, and I also wrote a blog earlier last month about this report, gathering all the information that I could (which wasn't much).

In any case, expect Japan to continue to be a hotbed of earthquake and volcanic activity for quite some time.

Japan's Sakurajima Volcano Has Violent Explosion

The Sakurajima volcano in Japan had it's most violent explosion since 2009, Japanese media and other sources are reporting. Japan's most active volcano in recent years, it had completed the year 2011 with the highest number of explosions on record since people began counting. Activity at the volcano shows no signs of slowing down.

Sakurajima is a complex stratovolcano with many vents, only a couple of the vents have been active in historical time. the volcanic complex is constructed within the Aira caldera, a massive caldera that formed about 22,000 years ago. Sakurajima is a post caldera cone, and has seen much activity throughout human history.

The Smithsonian GVP's summary of Sakurajima is as follows:

"Sakura-jima, one of Japan's most active volcanoes, is a post-caldera cone of the Aira caldera at the northern half of Kagoshima Bay. Eruption of the voluminous Ito pyroclastic flow was associated with the formation of the 17 x 23-km-wide Aira caldera about 22,000 years ago. The construction of Sakura-jima began about 13,000 years ago and built an island that was finally joined to the Osumi Peninsula during the major explosive and effusive eruption of 1914. Activity at the Kita-dake summit cone ended about 4,850 years ago, after which eruptions took place at Minami-dake. Frequent historical eruptions, recorded since the 8th century, have deposited ash on Kagoshima, one of Kyushu's largest cities, located across Kagoshima Bay only 8 km from the summit. The largest historical eruption took place during 1471-76."

Alaska's Cleveland Volcano Has An Explosion, Iliamna Rumbles Away

Alaska's volcanic activity is picking up. Mount Cleveland was reported by multiple news sources and AVO as having had an explosive event on Wednesday, although the cloud is reported to be far less in height than the 20,000 meters it would take to institute a no-fly zone. AVO stated "A small, short duration explosion was detected from Cleveland Volcano on distant seismic stations and infrasound arrays. The time of the explosion was approximately 4:05 UTC March 8 (7:05 PM March 7, AKST.) Weather cloud conditions prevented the detection of an eruption cloud in satellite images or visual observation of the summit. This explosion was similar to recent small events that occurred in December 2011 and produced small ash clouds that dissipated quickly and did not affect air traffic. At this time, no further activity has been detected."

And as Cleveland volcano slowly plods along with what seems to be akin to a slow motion, low explosive eruption, a volcano I have mentioned in a previous post, Iliamna, is showing more signs of dike intrusion. Heightened seismicity including very shallow quakes under the restive volcano, which has no recorded history of eruptions during human habitation in Alaska, is causing AVO to suspect what I have said in the past, that Iliamna is waking up, and is preparing to erupt. The last radiocarbon dates for any eruption at Illiamna are thought to be 140-300 years ago. A record number of seismic events (for Illiamna) is occurring, and AVO scientists are planning a fly by to check for any visual signs of a change in activity. They will be checking for steaming, fumeroles, melting ice, etc.

Today alone, Illiamna has had over 40 quakes, some of them not-so-small, with the largest being a 3.2 magnitude beneath the summit, at a depth of only 2.0km, closely followed by a 3.1 quake at a shallower depth of 1.2km. It is my humble opinion that Illiamna is indeed ready to erupt, and this will occur either this month, or this year. We will wait and see, but so far I have been right about this volcano, and as far as I know, I was the first to report on its unrest aside from AVO noticing the tremor waves (I could not find anything or any other news that was posted before this article). Maybe I'm on to something!

Current seismic tremor at Iliamna Volcano, from AVO website.

In any case, the amount of quakes today alone make me almost think an eruption is already occurring. If it isn't it certainly might very soon, and we have very little idea as to how this volcano will erupt, given that it has never been witnessed in eruption (the only info we have is forensic). The picture below shows the current (last 24 hours) swarm of quakes, while the quakes in Yellow have occurred within the week. 

Image from Google Earth with USGS real-time quake overlay.

Iliamna is a stratovolcano, common for the US's Pacific Ring Of Fire volcanoes, and is most likely capable, like most of its neighbors, of large explosive events. An eruption at Iliamna will most likely cause some disruption to air travel, as well as ashfall on nearby towns, however the immediate area surrounding the volcano is not populated by any permanent towns. This volcano will likely not be able to directly kill anyone, thankfully. Time will tell on this, but it is looking more and more like an eruption at Iliamna is imminent.

As of now, AVO has NOT raised the alert level for Iliamna, however if I were them I would at least consider at this point raising the alert level to "Yellow" (watch). It would be a tragedy if this volcano were to erupt as an airplane is flying over, much like the incident in the 1980's when Mount Redoubt suddenly blew and nearly caused a fatal crash.

The Smithsonian GVP says this about Iliamna:

"Iliamna is a prominent, 3053-m-high glacier-covered stratovolcano in Lake Clark National Park on the western side of Cook Inlet, about 225 km SW of Anchorage. Its flat-topped summit is flanked on the south, along a 5-km-long ridge, by the prominent North and South Twin Peaks, satellitic lava dome complexes. The Johnson Glacier dome complex lies on the NE flank. Steep headwalls on the southern and eastern flanks expose an inaccessible cross-section of the volcano. Major glaciers radiate from the summit, and valleys below the summit contain debris-avalanche and lahar deposits. Only a few major Holocene explosive eruptions have occurred from the deeply dissected volcano, which lacks a distinct crater. Most of the reports of historical eruptions may represent plumes from vigorous fumaroles east and SE of the summit, which are often mistaken for eruption columns (Miller et al., 1998). Eruptions producing pyroclastic flows have been dated at as recent as about 300 and 140 years ago (into the historical period), and elevated seismicity accompanying dike emplacement beneath the volcano was recorded in 1996."

I will probably post an entirely separate article should Iliamna decide to erupt.

*****UPDATE 3/11/2012*****

AVO has raised the alert level at Iliamna to Yellow. They posted the following statement:

"Over the past three months the earthquake rate at Iliamna Volcano has steadily increased and now exceeds normal background levels. Although it is not certain that this sustained increase in earthquake activity represents the movement of magma at depth, it is a significant change and AVO has increased the Alert Level to Advisory and the Aviation Color Code to Yellow. The current activity does not mean an eruption is imminent or certain. A similarly energetic episode of seismic unrest from September 1996 to February 1997 was likely related to the intrusion of new magma at depth, but an eruption did not occur."

It Is Official: El Hierro Eruption Has Ended

INVOLCAN has declared the eruption of El Hierro to be over, and the alert status of the island has been lowered from Red to Yellow. The village of La Restinga can finally open its doors to tourists again, however maritime activity is still restricted due to probable degassing, and swimming in the water is still off limits pending a chemical analysis of the water to determine its safety. Sea life has already begun to repopulate the area, a good sign for the fisherman of the village.

The eruption at El Hierro was preceded by a lengthy period of volcanic earthquakes, which were used to size up the magma chamber. The island was on Yellow alert for a long time, before a "jacuzzi" was spotted in the ocean, and harmonic tremor increased. The eruption of the underwater cone "Bob" started as an underwater fissure eruption, eventually resulting in a cone building event. Several collapses of the main vent stalled the eruption, which stopped and started several times. On occasion, floating "Lava Balloons", or gaseous bubbles encased in molten rock, would float to the surface and emit steam, and sometimes flames once the bubbles burst and allowed oxygen to interact with the heat. This however was as exciting as the eruption got.

For about a month now, the eruption has all but ceased entirely. Harmonic tremor has been at low to background levels, and there has been very little if any surface activity since February. This is what led the scientists to declare the eruption over, although their maintaining of alert level Yellow does indeed reflect what many of us know, that activity can resume at any time, and caution is still in order. Some volcanoes have a small cone building event as a precursor to a larger eruption, something that is certainly not out of the question.

Current uplift sensors show the island to be stable, which could mean that the magma reservoir has not deflated, and merely extruded the lava to form "Bob" because it was the easiest path to the surface. Quakes are still ongoing at El Hierro in an area not near "Bob", and it is still worth keeping an eye on the island. El Hierro and the Canaries have been compared to the Hawaiian islands in regards to the type of eruptions it produces. The theory goes that El Hierro, like Hawaii, is a hotspot type volcano. These are highly unpredictable as we have no way of imaging or monitoring the mantle plumes that are though to be responsible for hotspot volcanoes.

It is my guess that activity will pause now for probably months, and either slow subsidence will take place, or activity will resume in another location. It is now a game of wait and see. In any case, I doubt that the residents of El Hierro will ever forget now that they are living on an active volcano, and will be ever mindful of the power that lies beneath their feet.

Kamchatka's Bezymianny Volcano At Highest Alert Level

(Reposted from KVERT)

Bezymianny report from KVERT:
Issued: 20120306/2332Z
Current AVIATION COLOR CODE: RED
Source: KVERT
Notice Number: 14-12
Volcano Location: 55°58'N, 160°36'E;
Area: Kamchatka, Russia
Summit Elevation: 9,496 ft (2,895 m)

Prognosis of Volcanic Activity: Activity of the volcano continuously increases. Strong ash explosions up to 43,000 ft (13 km) a.s.l. possible at any time. Ongoing activity could affect international and low-flying aircraft.Volcanic Activity Summary: Activity of the volcano remains high. Seismic activity began to grow on February 12: about 7-19 weak seismic events were registering each day till February 29; about 25-43 weak seismic events and episodes volcanic tremor were recorded each day on March 01-05. Probably there is a preparation of a strong explosive eruption of the volcano. According to satellite data, a size and a brightness of a thermal anomaly abrupt increased on March 02, and continues to increase.Volcanic cloud height: No ash cloud produced at present.Other volcanic cloud information: No ash cloud produced at present.Remarks: Bezymianny volcano is one the most active volcano of the world. In 1955, for the first time in history, Bezymianny started to erupt and after six months it produced a catastrophic eruption with the total volume of eruptive products over 3 km3. The lava dome began to grow in the explosive caldera immediately after the catastrophe and continues at now. 42 Vulcanian-type strong explosive eruptions of Bezymianny occurred in 1965-2011, while 20 of them producing ash up to 10-15 km a.s.l. Last explosive eruption occurred on April 13, 2011.

Supervolcanoes And Why You Shouldn't Worry So Much

It's a pretty quiet week in volcano world (at least until I can get my paws onto the latest GVP report), so I thought I might dabble in the realm of supervolcanoes today, since they are such a hot topic, and very misunderstood.

There has been plenty of hype in the news media surrounding so-called supervolcanoes like Yellowstone, Toba, Rotorua, Uturuncu, and the like. Media outlets looking for a sensational and fascinating story seem to fixate on the apocalyptic scenarios of a Yellowstone eruption, or an eruption so devastating that it wipes out humanity as we know it. While there are supervolcanoes in our midst, and some like Yellowstone that are still seething and breathing, a true supervolcanic eruption has never occurred in the span of recent human history, and probably will not for a very long time.

Yellowstone had its last truly catastrophic eruption some 600,000+ years ago. Journalists and some researchers point out that Yellowstone has a major caldera type eruption around every 600,000 years, and some say the volcano is overdue. But this again assumes that volcanoes actually have a schedule, and conform to our time lines. This of course is absurd. Volcanoes erupt simply when the conditions are met for an eruption, and Yellowstone is a far ways away from anything major. At the very worst, we'd probably see a small phreatic (water explosion) eruption, or a minor cone building event, but even this is far fetched at this point in time.

The ONLY supervolcanic eruption in human history occurred approximately 75,000 years ago in Indonesia. A volcano named Toba erupted, punching a gigantic caldera into the earth's surface, creating a mini ice age, and reducing the population of humans worldwide to around 5,000 individuals. This has been proven from many angles like ice-core samples that show an immense amount of sulphur dioxide and tephra, as well as DNS analysis of humans pointing to a genetic bottleneck around that time.

The next largest eruptions in recorded human history were the eruptions of Tambora in the 19th century, the eruption of Krakatoa (now Anak Krakatau, 'child of Krakatoa), and the eruptions of Mt. St. Helens, and Pinatubo. These eruptions were all on a scale of VEI 6 to VEI 4. Far from the supervolcanic force of a VEI 7 eruption which is required to be classified as a supervolcanic event.

There are no supervolcanoes currently displaying the characteristics of an imminent eruption. The requirements for such an eruption are extremely rare, and complex. First, the magma chamber has to be massive, fully charged, and pressurized, and then it needs an injection of fresh magma from the mantle. Surface observations would include heightened fumerolic and geyser activity, ground uplift and swift deformation, accompanied by multiple explosive events, culminating in the emptying of the magma chamber, and subsequent collapse of a massive caldera. There are NO volcanoes that currently display any of these characteristics... not even Yellowstone or Uturuncu.

Events like these are extremely rare, and require all of the above conditions to occur. Given that the earth has already suffered so many volcanic eruptions, and several supervolcanic events, one might wonder if the Earth still has the magma required to make one happen. It does, and supervolcanic events will happen again... but the likelihood of one happening in your lifetime is so infinitesimally small, they're hardly worth the calculation. In fact, you have a much better chance of seeing a meteor strike the earth, or a supernova in space than you are to see a supervolcano erupt.

Supervolcanoes are terrifying, fascinating, and worrisome for governments to prepare for... but one has to ask... given that we've never had a super eruption in our living history, why would we lose sleep over something that is so unlikely to occur? Most of the worry and hype can be blamed on the "2012'ers", Hollywood, or just plain old Yellow Journalism. Some can be blamed on conspiracy theories, or doomsayers. But truly, it is human nature to be on guard about any threat to our existence, and while the threat exists, we will always pay attention. I however will never lose any sleep worrying about Yellowstone.