El Hierro Activity Ramping Up Again

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

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

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

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

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

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

Large Quake Swarm At Katla Volcano

Katla volcano is again showing increased seismicity and unrest, as the Icelandic cold season comes to a close. Today there were over 25 small quakes within the caldera, with most of the quakes in the range of 1.0-2.0 in magnitude. Katla volcano has long been thought to be overdue for an eruption. As the train of thought goes, as goes Eyjafjallajökull, so goes Katla shortly thereafter. This has proven to be somewhat of a guesstimate,  as Katla has refused to blow even after the 2010 eruption of Eyjafjallajökull which caused massive disruption to transportation in Europe.

Katla has been having near continuous quakes under its caldera for decades. While lately it may seem that Katla is preparing to blow, it should be noted that many quake swarms occur in the area regularly. These quakes are probably (almost definitely) related to magma intrusion into the caldera, it remains a phenomena that is unlikely to produce a massive eruption.

Katla volcano is covered in a thick glacier, and as such has somewhat of a natural eruption suppression system in place, given that the ice sheets are so thick. The volcano does frequently have magma intrusion, but most of the time, the ice mitigates this and simply causes glacier outburst floods (jökullhlaups) to occur, typically not resulting in explosions. However when Katla builds enough pressure, the result can be disastrous.

The current activity at Katla volcano is not a surprise, nor unexpected, and probably will not result in a whole lot of action. The media such as the BBC, or the Telegraph, will most likely blow this out of proportion. It is important to note that Katla frequently has quake swarms, dike intrusions, etc, that do not immediately manifest themselves as volcanic activity. However there is always a risk that an eruption could occur as a result of these magmatic intrusions into the volcanic system.

As always, time will tell if this will result in anything. A good 90% of the time, quake swarms are merely a distant precursor to a future eruption and nothing more. Sustained swarms are the ones to watch for, and given the past few weeks, I'm fairly certain that this is simply normal behavior for the volcano. Nonetheless, it is a noteworthy swarm, and you can watch the near real-time activity at http://en.vedur.is.

Quiet month

There isn't a whole lot going on in the volcano world this month. The usual suspects are still erupting (you can see them at http://volcano.si.edu), and the rest of the world for now is pretty quiet. I have not been posting blogs lately as I am still in the midst of setting up my new computer system and importing my volcano databases, earthquake monitoring programs, and other neat plugins that show what the Earth is up to.

Rest assured as anything of particular interest occurs, I will certainly post about it.

I would however like to take an opportunity to say thank you to my readers, and those who are supporting this blog. It takes a lot of energy, and contemplation to write a blog that is worthy of your time, so to those that take the time to read when I post an article, I would like to say thank you.

The lull in volcanic activity this month is always a good thing for those that live around volcanoes, except of course for communities that depend on volcano tourism. Most of the volcanoes erupting currently are volcanoes that are either in a continuous state of eruption, or are frequently in a state of unrest. There have not been many reports lately of any volcanoes that have erupted with any amount of surprise.

Cheers to that!

Italian Government Approves Drilling Into Campi Flegrei

The Italian government has reversed a previous decision to disallow drilling into the Campi Flegrei supervolcanic region after concerns about the potential for increased seismicity and triggering of a super eruption were assuaged. The government had previously banned the project, which aims to drill some 4km below the earth's surface in the caldera to gain more knowledge about the composition of the massive magma chamber. Concerns were raised that drilling could cause an eruption, or dramatic rise in earthquakes.

Italy's relationship with geologists was recently damaged when Italian courts charged scientists with "failing to accurately predict a large earthquake" last year, in a move that was decried by the larger scientific community.

The new drilling plan is actually an investigatory operation that is going to look into the potential to develop geothermal energy in the area, as well as gauge the potential for future eruptions. The region has seen massive uplift since the 1960's, with former nautical ports that used to be below sea level now rising approximately 10 feet above it. This means inflation.

Inflation of magma chambers does not mean an eruption is imminent, but it is certainly motion towards a possible eruption in the future. However many so-called supervolcanoes regularly breathe in and out, from Yellowstone, to Long Valley, and of course Campi Flegrei. Campi Flegrei was last active in 1538, when the Monte Nuevo volcanic cone was formed. So the volcano does in fact have a record of recent historical eruptions, unlike the Yellowstone or Long Valley calderas. In fact, it is one of the only supervolcanoes on earth to have erupted in historical time, aside from the massive eruption of Tambora in 1815 (a VEI 7 event) which caused the famed "Year without a summer".

While it is highly unlikely that any drilling into Campi Flegrei would ever cause such a massive event, it is absolutely possible that minor quakes and tremblors will result from drilling into the magma chamber. Many volcanoes and volcanic areas around the world experience heightened seismicity, such as Clear Lake on the US West Coast, Hengill in Iceland, and Salton Buttes (Salton Sea). It would not surprise me in the least if drilling caused minor mag 1.0-3.5 quakes if the area is in fact developed into a geothermal farm.

In any case, the data produced by the investigative drilling will be of significant interest to the scientific community, and to the Italians, who live under constant threat of some very large, and very powerful volcanoes like Vesuvius. Better understanding of their volcanoes can only help the community and the world at large prepare for an eventual eruption.

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.