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.

El Hierro Eruption Officially Over?

Reports from earthquake-report.com are saying that INVOLCAN will officially declare the eruption at El Hierro to be over today, possibly lowering the overall alert level to "green" and allowing the village of La Restinga to slowly return to normalcy. Tremor for the past few weeks has been at a minimum, with little to no changes, save the very slight increases and decreases in amplitude, and occasional small earthquakes. For now it seems, the eruption of "Bob", the submarine volcano that ALMOST made it to the surface of the water, is over.

This however does not mean that activity on the island as a whole is finished. Indeed, deformation is still occurring, and earthquakes are getting shallower at other locations around the island. So, while the village of La Restinga may be able to breathe a sigh of relief that "Bob" has gone to sleep, the rest of the island as a whole is still on pins and needles. The last eruption of El Hierro occurred in the 18th century, and lasted two years.

While many volcano enthusiasts and scientists alike were watching El Hierro with anticipation of being able to see a well-documented Surtseyan type eruption (which ended up not happening), the island chain of Jebel Zubair in Yemen pulled a fast one on us and had an island-producing eruption behind everyone's back. Quite frustrating if you were hoping to witness the actual birth of an island from start to finish. It's really too bad that the Zubair group of volcanoes isn't really monitored that well, or we might have gotten our wish.

All things said and done, the ending of the El Hierro eruption, and the lowering of the alert level for La Restinga will likely come as a relief to islanders, as they have been hurt economically by the closure of the fishing port, and the hotels/cafe's which were evacuated during the heightened alert. While the local and Spanish governments might have used the eruption as a tourist draw, like they do on Hawaii or Iceland, the local media hyped the story and scared lots of people and tourists from the island. Only bloggers, and locals were actually reporting on this eruption objectively (or close to objectively), which has given me much more respect for bloggers and freelance journalism.

In any case, my best wishes to the residents of El Hierro, and hopes that if activity does resume, or start in another area, it will be as mellow as the eruption of "Bob", and merely be an interesting, not violent, occurrence. Time will tell if the island has gone back to sleep, but as far as the local government and the scientists at INVOLCAN are concerned, it's time to consider the eruption over... but a word of caution, I'm pretty sure volcanoes don't have to follow government law or statements... we're living on their schedule, not the other way around.

Even though the eruption has "officially" ceased, there will be some remnant activity at the volcano, such as degassing, and occasional structural adjustment quakes.

Katla Volcano Showing More Tremor

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

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

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

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

NASA MODIS Satellite Captures Remote Eruption

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

Image from NASA MODIS Satellite of Tinakula in eruption.

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

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

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

El Hierro Volcano Eruption Winding Down

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

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

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

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

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

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

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

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

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

Eruption at El Hierro Slows, But Quakes Increase

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

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

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

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

El Hierro Tremor Increases, Activity Resumes

2/09/2012

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

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

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

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

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

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

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

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

Decreasing tremor at El Hierro today.

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

Below is the current tremor readings for today.

                           

Mount Cameroon in West Africa Erupts

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

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

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

(From Smithsonian GVP):

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

Powerful Tremor This Morning At El Hierro, Then Significant Decline

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

The current tremor graph below:


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

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

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

*****UPDATE*****

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

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

Tremors at Eyjafjallajökull and Katla (Iceland) Today

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

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

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

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

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

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

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

El Hierro Activity Strong Today, Volcanic Tremor Vigorous

The El Hierro Volcano has picked up activity this morning and into the afternoon with strong harmonic tremor, multiple recorded underwater explosions, and lots of steaming lava rocks floating to the surface. The tremor began to pick up before dawn at El Hierro, and continued throughout the day with one of the most vigorous displays of activity yet. This volcano is far from done erupting.

Below is today's tremor graph from IGN.

The obvious increase in volcanic tremor this time did coincide with surface activity. Even though the tremor is currently a bit lower than earlier, smoking lava stones and a very strong and colorful stain on the ocean surface can easily be seen on the live webcam.

If El Hierro can sustain this eruption for a couple more months, it is highly likely it will breach the surface and enter into a Surtsetyan, or island building phase. This would be characterized by a large increase in emissions and explosive activity, eventually (probably) resulting in a more Strombolian type eruption from the cone (at least this is what I gather will happen when the cone can get free of the water, given the type of ejecta making its way to the surface). With gassy lava like this, it will probably end up being quite a show.

It is time for those of you who gaze at the volcano to remain vigilant. I for one would be overjoyed to see the birth of this new island live on camera (of course I'd rather be there, but that costs lots of money!). Keep your eyes peeled!

After Two Day Break, El Hierro Roars Back To Life

The last two days at El Hierro saw a calm stain on the water with few if any smoking lava stones, low harmonic tremor, and very little else. That ended this morning, when tremor again picked up, more smoking stones could be seen on the surface and emissions bounced back. El Hierro is not done yet.

                                                                                    

Images from El Hierro Telefonica/Movistar cam.

Today's current tremor. note the large increase over the last couple of hours.

El Hierro has been doing this off and on again eruptive cycle for weeks now, if not months. This is probably related to vent collapse and re-pressurization, leading to sporadic bursts in activity. Likely this will keep going on for quite some time. Tremor is QUITE strong today, so if you have the opportunity, you should check out the cam and keep your eyes peeled for some cool activity.

The Mechanics of the El Hierro Eruption (and current update)

The El Hierro volcano is a vexing one to watch and attempt to predict. While predicting any volcanic activity is not a science, more of an art, there are some typical signs for volcanic eruption that most scientists use to gauge the intensity, duration, and potential eruption time window. For El Hierro it seems, a lot of these rules are out the window and useless.

Harmonic Tremor (HT) is a seismic signal that is typically generated after preceding earthquakes, which indicates moving magma underground. This is usually indicative of an ongoing or soon to be starting eruption. This is not always so however, as El Hierro has proven time and again during this eruption. Some days, there are many smoking lava balloons and an intense jacuzzi, despite an absence of HT or earthquake activity. Slow effusion of underwater lava it seems can be independent of any HT signal. This has been the case now for weeks.

To scientists and remote bloggers, using HT monitors could give the false impression that the eruption has ended (Jon Frimann of the Iceland Volcano Blog uses this reasoning a lot). Without visual confirmation of the cone underwater, some bloggers leap to the conclusion that with an absence of strong HT, that the eruption MUST be over. If you were looking at an erupting cone, but your seismographs weren't showing any tremor, would you believe your eyes, or your instruments?

There are of course many other indications of an ongoing eruption. Gases, CO2 and SO2, can tell scientists what is going on inside the magma chamber. SO2 is usually indicative of a stable, and mild eruption, while large spikes in CO2 usually precede larger explosive activity. Monitoring these gases in real-time is the best way to really gauge the 'attitude' of the volcano at any given moment. CO2 and SO2 emissions at El Hierro remain stable, which suggests a stable eruptive cycle for now. If there are any spikes or dips, this could merely mean the magma chamber is either gearing up for a large explosion, or simply recharging/reloading.

Despite the fluctuations in HT and SO2/CO2 emissions, the visual observations of El Hierro don't seem to match up with instrument data very often. This is a unique volcano, like all of the other volcanoes of the world, and each has its own mechanisms for erupting, so using old methods from more active volcanoes simply will not produce the same results. Its important for those that monitor this volcano to realize that the eruption will only be "over" when the volcano is out of juice. Given the long duration of this eruption, and the supposed size of the magma chamber, I don't see this eruption ending any time soon. It will likely go on for a few more months, if not a year.

We do not know the exact size of the magma chamber, but like the Hawaiian Islands, Iceland, and other "hotspot" type volcanoes, eruptions can last years, or simply have a tiny eruption. The eruption at El Hierro is very much like the eruptions of Hawaii, specifically those of the Loihi Seamount, where an underwater volcano (that last erupted in 1996) is expected to one day create a new Hawaiian Island (in about 10,000 years or so!). The eruption at El Hierro is much shallower than Loihi so the time table here is around a couple of months if it keeps going. There has been an ongoing eruption in Hawaii from Kilauea since 1983, proving that sustained eruptions can and do occur on hotspots. This could be the beginning of a long term eruption at El Hierro... I would not be surprised.

This morning El Hierro is displaying vigorous jacuzzi activity, with occasional bursts of smoking lava stones. HT is gradually picking up again (which only means that somewhere in the chamber, magma is moving), and a few quakes were recorded. The activity has consistently ramped up on the surface the closer the vent gets to the surface of the ocean, and I expect it will continue to do so.

3.8 Magnitude Quake in Clear Lake/Geysers California

A magnitude 3.8 quake hit Clear Lake today at around 4:30am north of the normal seismic swarm region. Typically, the Clear Lake geothermal prospect can cause up to 50 small quakes a day, many ranging from 1.0-4.0. 3.8 is a bit larger than the area usually sees, and this quake is different due to its location and size. The area where this quake occurred is at the SE shore of the lake, not near any geothermal drilling or activity. This is most likely a tectonic event and not magma movement, although the area is considered to be an active volcano.

Above image from Google Earth with real-time USGS layer added.

Waveforms of the quake from USGS website.

The Geysers Geothermal Field/Clear Lake area has had an ongoing quake swarm since geothermal power plants were installed on the mountain range south of the lake. This has been going on since the late 1990's. While information on this activity is hard to come by, and the science papers released mostly being from corporate scientists with interests to protect, it is anyone's guess what's going on in this area. The wave forms do appear to be tectonic from this quake (above), so it's probably not a cause for concern. As always though, I will keep my eyes peeled on this location to see if anything new develops (but I'm not going to lose any sleep over it).

Activity Strong Today At El Hierro

The Canary Islands volcano does not seem to want to quit. Despite reports around the web and other blogs that say "El Hierro Eruption Stops", it seems again that El Hierro is making fools out of those who try to predict this volcano. Today the activity is quite high, with more lava balloons (gas filled lava that floats on the surface of the water) visible day and night, and a very strong "jaccuzzi" area present during the afternoon at El Hierro (below).

Picture from Movistar/Telefonica webcam.

El Hierro has been in a sort of on-off-on-off-on pattern with its eruptions, probably due to structural adjustments and dome collapse underwater. Once magma pressure builds again, activity resumes. This is probably indicative of a large magma chamber beneath the island. My guess is that the volcano probably has plenty of life in it yet, and that we can't expect it to stop anytime soon.

Pictures posted on Earthquake-report.com from the local scientific expeditions show that there are now two vents active underneath the water. The main vent, lovingly referred to as "Bob", and a nameless vent closer to the shore, but much smaller. The dual jaccuzzis can be seen in the image above. 

The main vent is now a mere 30-50 meters below the sea surface, and if activity continues, we will most likely bare witness to a surtseyan eruption within a couple months. Just last month a similar eruption created a new island in the Jebel Zubair chain in Yemen. Since that area isn't closely watched, and is rather deserted, that eruption was a surprise only identified by local reports and satellites. Scientists did not witness the start of the eruption underwater, and thus only knew of the eruption once it breached the surface, so we have no way of knowing how long Jebel Zubair erupted for. 

We are fortunate with El Hierro to see the precursors to the eruption in the form of a vast amount of earthquakes, along with the underwater cone building phase, and hopefully the surtseyan island forming phase. This will have been a complete record of an eruption, and will no doubt be invaluable to science.

El Hierro Volcano Still Erupting

The eruption at El Hierro continues at a steady pace. Harmonic tremor has fluctuated during the past few weeks, with tremor picking up in the last couple of days following a supposed vent collapse (possibly two). Last night, viewers of the webcams reported seeing flaming lava balloons on the surface of the jacuzzi area, with sporadic increases and decreases in jacuzzi intensity.

As of this writing, tremor is picking up, which has become somewhat typical following vent collapse. This is a result of re-pressurization of the vent magma chamber, which will likely result in further underwater cone building and subsequent collapses, until the volcano either breaks the surface and enters a surtseyan eruptive phase, or the eruption ceases altogether.

El Hierro volcano has vexed bloggers, enthusiasts, and scientists alike, with frequent stops and starts to the eruption action. Some bloggers like John Frimann (Iceland Volcano And Earthquake Blog) and Earthquake-report.com (who currently has the best equipped coverage of the area, sans opinions) have previously reported the eruption to be over, which is obviously not the case.

As is sometimes a fact with long dormant volcanoes, eruptions can be long lived, or short in duration. The eruption at El Hierro was preceded my many thousands of small earthquakes, which resulted in a good picture of the girth of the magma chamber, which it turns out, is quite large. This is one of the least studied volcanoes in the Canary Islands, if not THE least studied. So most of the info about El Hierro is quite new.

The magma chamber is large, and has clearly made a channel to a massive magma source, probably deeper than scientists are currently able to measure without the aid of a massive seismic network, or the newly minted muon scanning technology. Judging from the earthquakes alone, in conjunction with depth, magnitude, location, etc, it seems this eruption probably has plenty of pressurized magma to feed activity for months to years.

In my opinion, this will be a very sustained and long eruption, possibly resulting in the creation of a new island. If the volcano ever does break the surface of the water and enter a land-building phase like the new island in Yemen (in the Jebel Zubair chain), the eruption will likely speed up with no water pressure to hold it back. A lack of water at the vents surface would allow the eruption to "blow its load" so-to-speak, resulting in probably a quicker release of magmatic gas pressure. This of course is only my theory.

In any case, the eruption continues unabated, and is beginning to develop a pattern of vigorous cone growth followed by periodic collapses and a subsequent increase in tremor and pressure. The lava balloons on the surface seem to indicate a very even flow of lava to the vent area, very consistent.

I will post more updates if anything interesting occurs. 

Headaches For South American Travellers As Puyehue Cordon-Caulle Continues To Erupt

BBC news and local websites are reporting that Argentina's airport in Bariloche, which was closed due to the eruption of Puyehue Cordon-Caulle volcano in Chile, had reopened three days ago after a 7-month closure due to volcanic ash, only to close again today as another wave of ash fell on the airport. I guess you can say this is the Southern hemisphere's Eyjafjallajokull moment. Airports as far as Melbourne, Australia have been forced to close due to the amount of ash in the air, as this volcano continues a strong eruptive cycle.

Chile's  Puyehue Cordon-Caulle volcano sprang back to life last year with major ash emissions coming from the Cordon-Caulle fissure system. The eruption has ejected many thousands of tons of ash into the atmosphere, and the ash cloud has recently circumnavigated the entire southern hemisphere. The current eruption has been characterized as highly explosive, with a VEI of 3, and has ejected pumice, effused lava down the flank, and has so far released enough energy equivalent to 70 nuclear bombs!

The eruption has forced closure of over 10 airports in the Southern Hemisphere, and has caused travel delays and chaos for months. However, like the Icelandic eruption of 2010, it is far better to be late, than to be dead, so I'm certain airlines are erring on the side of caution in this case.

Aside from the ashfall, and danger of lahars, the volcano has not caused any deaths or fatalities (directly) from the eruption. It has been erupting since April/March of 2011 and so far shows no signs of quieting down.

Eruptions from this volcano are somewhat rare, with many reports of historical eruption highly questionable, with the exception of the 1914, and 1960 eruptions.

Costa Rica's Turrialba Volcano Alert Level Raised To Yellow

Costa Rica's Turrialba volcano has been raised to alert level "Yellow" in response to reports of increased seismicity, and emissions. Residents and pilots reported seeing a gas plume (possibly containing ash), and some photos seem to confirm this (below). Turriabla has had several major explosive eruptions in the last 3200 years, with most historical activity being fairly small (some phreatic eruptions and minor explosive events). It is anyone's guess as to how this particular volcano will behave if it does decide to erupt.

Turrialba Volcano in Costa Rica (Credit not given from original website)

Increase emissions with ash and gas do not always lead to a major event. The volcano Cerro Hudson in Chile recently came out of 'hibernation' and gave a small 'burp' of ash and gas for a couple days, but then quieted down quickly. As the M.O. for Turrialba seems to be many brief, weak events, with the very occasional large event, this event will likely be small and brief. Time will tell.

Costa Rica has many active volcanoes, 5 of which are the typical repeat offenders (Poas, Irizu, Arenal, Rincon de la Vieja, and Turrialba) as far as frequent eruptions. Of the volcanoes in Costa Rica, only a few have little to no historical volcanic activity (Tenorio, Miravalles, Orosi, an Platanar). The four least active volcanoes doe however display hydrothermal or fumerolic activity, and were considered to be of Holocene age by the Smithsonian GVP, and their referenced volcanologists.

Costa Rica, like most Latin-American countries, the US, and Canada lie on the Pacific Ring of Fire. Costa Rica, is prone to frequent eruptions from Poas, and Arenal (very rare to see these volcanoes dormant).

Quiet Week in Volcano World

This week has been so far pretty quiet as far as new or interesting geological events, but a few have occurred.

Indonesia suffered a 7.3 Mag Quake off the coast of Sumatra, prompting the government to issue a brief tsunami warning (even though the Pacific Tsunami Center stated that there was no tsunami... I'd be freaked out if I were them too!). The quake did not damage any buildings.

Chile's Callaqui volcano appears to have either never erupted as reported, or had a very brief, non-explosive event. It is now thought that the volcano was merely exhibiting vigorous fumerole steaming.

El Hierro is in a holding pattern, with tremor at a medium level, and the stain on the ocean surface persistent. Not a lot has changed since the last post.

The quake swarm that was occurring at Mono Lake in California appears to have subsided or ceased. If this was magma dike intrusion, it was a very small one.

The quake swarm at Sierraville, CA (which scientists do say is a magma dike intrusion event) is ongoing after taking a few weeks off.

The volcano Sakura-Jima in Japan broke its previous record for the most explosive eruptions in a year -- around 980! (This is one of Japan's most active volcanoes).

Jebel-Zubair off the Yemen coast is still erupting and building more land, however the eruption (at last glance) appears to be subsiding. Based on the size of the other islands in the area, it is reasonable to assume this will be a short eruption, with a lasting island (given the lava composition).

If anything new or interesting occurs, I will surely post about it! There has not been a brand-new eruption to report on so far this year, so I will update some other volcanoes I am monitoring. Stay tuned!

Vigorous Steaming at El Hierro Volcano

Morning webcam stream shows a VERY strong steam area over the vent at El Hierro. This indicates the vent is getting near to the surface, or temperature has drastically increased near the surface of the water. The steaming is constant, and lively, with occasilanl lava rocks coming briefly to the surface before they sink back down. It is quite possible that the volcano will legitimately enter the Surtseyan phase soon enough.

                               

The column of steam near the surface this morning.

The eruption at El Hierro has been a bit erratic lately, occasionally looking like it's going to end, but the volcano has continuously been erupting for months now, with at least no visual signs lately of slowing down. Indeed, this vigorous steaming is about the most active the surface has ever been during the eruption, with the minor exceptions of a brief explosive event during the evening, and burning lava rocks occasionally visible at the ocean surface.

As of this writing, the column of steam coming from the water is quite persistent, and I see no reason why this eruption would end at this point. Time will tell. The eruption thus far has proceeded at a very slow pace. The island had plenty of warning via thousands of earthquakes, and the vent that opened up south of La Restinga has slowly but consistently grown, collapsed, and grown again. It seems the volcano is in no rush to breach the surface, but that could change at any time.

The steam so far seems to be a combination of floating steaming lava rocks, and very hot water. From what I saw this morning, I did not see a great many floating rocks, and the ones I did see didn't stick around too long. This looks to me like the water is incredibly hot, meaning that either the eruptive force down below is becoming strong enough to boil the water near the summit, or the summit is closer to the surface. Time will tell, and this new activity hasn't gone on long enough for INVOLCAN to take a close up look scientifically. Likely this will take some time. Updates will be posted tomorrow.

As of about 10:30am PST, the Movistar/Telefonica webcams appear to be offline. Earthquake-report.com is urging people to tweet:

@movistar_es ¡Las webcams de la erupción volcánica en El Hierro NO FUNCIONAN! Hay mucha actividad, por favor arreglarlas pronto. Gracias

which translates to: The El Hierro eruption webcams DO NOT WORK. There is a lot of activity, please fix them as soon as possible. Thank You

I would certainly "tweet" this message, if I were a Twitter user (nothing I have to say is 140 characters short!), so if anyone that reads this would like to use their tweet power to help get the cams back online, I'm sure all of us "Bob" fans would greatly appreciate it!