2.0 Magnitude Quake Strikes Eyjafjallajökull

A Magnitude 2.0 quake struck the Eastern flank of Eyjafjallajökull today, near the same spot of the initial fissure eruption at Fimmvörðuháls. There could be many explanations for this quake, such as structural settling of the post-eruption fissure region, or resumed intrusion of magma into the Eyjafjallajökull-Katla transform region. It is simply too early to tell as this quake pretty much happened within the last hour, so this will be a short post until/if anything further occurs in the region.

There were also two >1.0 mag quakes within the Katla caldera.

Other areas of Iceland experiencing heightened seismicity include the Reykjanes peninsula near the Brennisteinsfjöll volcanic field where more than 27 quakes, two above magnitude 3.5, have struck within the last 24 hours. An area to the East, near Hengill volcano is experiencing continued seismicity due to geothermal exploration and power generation (Iceland is the worlds biggest user of geothermal energy). The quake swarm at Brennisteinsfjöll is strong, and is probably related to magma dike intrusion, however the area has not seen any eruptions since the 14th century, so it is difficult to say what's happening here. Harmonic tremor is being detected at this location, so the quakes are most likely volcanic in nature.

Tremors at Reykjanes peninsula within the last 48 hours.

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

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

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

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

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

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

*****UPDATE*****

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

New Earthquake Swarm in Katla Volcano

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

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

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

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

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

Image copyright Iceland Met Office.

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

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.