Katla Volcano Caldera Earthquakes
July 9, 2010, Submitted by: Ken
Since 17-May-2010 until this post 9-July-2010, there have been approximately 96 earthquakes at the Katla volcano site within the region of the Myrdalsjokull glacier. Of the 96 earthquakes, 27 have been within the Katla caldera. The image shows the earthquake locations with respect to the past volcanic eruption sites of 1755, 1823, and 1918. There was also a suspected region of eruption during 1955 which never broke through the ice glacier. It is located on the eastern edge of the caldera.
As you can see, only a few of the earthquakes occur directly underneath a previous eruption location, while the majority occur around the perimeter, particularly the east-northeast perimeter. Several others are scattered in other locations within the caldera.
It is interesting to note that of the approximate 96 Katla earthquakes since 17-May, the majority have occurred just off of the northwest rim of the caldera as you can see in the image above.
Katla has been fickle during the past number of weeks in that there have been days when hardly an earthquake has appeared, while there have been other days that have been fairly active. There was one stretch of several weeks that was very quiet, while during the past several days there has been quite a lot of activity, much more than average since I’ve been watching this.
Katla historically erupts following the eruption of Eyjafjallajokull (which first erupted April 14). Katla is about 10 times more powerful, and has the potential to cause worldwide disruption.
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Katla Volcano 10X or 100X Eyjafjallajokull
June 18, 2010, Submitted by: Ken
When Iceland’s Katla volcano erupts next, could it be 100 times as powerful as the recent Eyjafjallajokull eruption?
Maybe, yes. Hopefully not. Probably not, but, let me explain…
The current thinking and assumption is that Katla will possibly be as powerful as ten times that of the recent eruption of Eyjafjallajokull, which is a reasonable expectation given the fact that the 1918 Katla eruption was indeed almost ten times as powerful as Eyjafjallajokull.
Volcano explosiveness is ranked on a scale from 0 to 8 (Volcanic Explosivity Index – VEI), and each increase in number represents a ten times increase in explosiveness (logarithmic scale). The total volume of ejected material also known as ‘tephra‘ (the fragmental material, regardless of size, produced by volcanic eruption), as well as plume height are the most important criteria factored in to VEI.
The recent Eyjafjallajokull volcano eruption in Iceland was ranked on the low end of VEI 4 and released about 140 Million cubic meters of material , of which about 80 Million cubic meters went into the atmosphere by way of the ash plume. It affected aviation in the region for weeks, translating to global transportation issues of both human and cargo, and had a measurable negative economic impact.
Imagining the impact of a Katla eruption on a scale of ten times worse than Eyjafjallajokull is bad enough, but when considering an impact of one hundred times worse, one begins to cringe…
VEI 4 (ejects .1 – 1 Billion cubic meters of tephra, plume height 10 – 25 km)
VEI 5 (ejects 1 – 10 Billion cubic meters of tephra, plume height >25 km)
VEI 6 (ejects 10 – 100 Billion cubic meters of tephra, plume height >25 km)
The 1918 Katla eruption has been ranked VEI 4+ and VEI 5, ejected 700 Million cubic meters of material, was about ten times the explosive power as Eyjafjallajokull, and nearly comparable with the 1980 eruption of Mount St. Helens.
The fact is, the magma chamber beneath Katla is large enough to produce a VEI 6 eruption. The chamber has a volume of about 10 Billion cubic meters and the caldera has an area of about 42 square miles (108 square kilometers). The total volume within the magma chamber, if completely filled and ejected, could touch the bottom range of a VEI 6.
When Katla erupted in 934 AD, it produced one of the world’s largest known lava flows which amounted to 18 Billion cubic meters while also ejecting 5 Billion cubic meters of tephra. This put it solidly within VEI 5 and would certainly have been VEI 6 if some of the enormous amount of lava had ejected as tephra instead.
History often repeats itself
Whether Katla goes off as a VEI 4+, 5, or 6, it will have a significant impact on today’s world. Regardless of the scale, air travel will be severely impacted, particularly in Europe, which will ripple down through the economies of the world. Localities in the path of the ash plume will likely endure regional crop and livestock failure from ash fallout, as well as the threat of poisoning from inhalation.
History favors a probable VEI 4+, maybe VEI 5 type of event, however a VEI 6 worst case scenario will bring significant devastation in that it will be much wider spread. It will surely have a global impact as temperatures could drop enough to cause wide spread crop failures while our weather is effected from such a large volume of ash ejected into the stratosphere. Having said that, even a VEI 5 could also cause a world wide temperature drop depending on which end of the VEI ’5′ scale.
Katla historically erupts following the eruption of Eyjafjallajokull (which erupted 14-April and went on for 10 days). Katla’s volcanic eruptions have ranged in duration from 13 days to as long as 120 days, while the last three Katla eruptions have been between 20 and 28 days.
We will not know the answer to the question of 10x or 100x until it happens, but in the mean time, if I lived nearby, I would stock up with some extra food and water just in case the disruption is bad enough. We all know that it will happen, it could be tomorrow or months from now, but the clock is definitely ticking.
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Katla Volcano 3 Earthquakes in Seconds
June 11, 2010, Submitted by: Ken
Friday, 11-June-2010, 07:03 this morning, an earthquake shook at the Katla volcano in Iceland.
10 seconds later, a slightly larger magnitude earthquake struck.
10 minutes later another earthquake trembled followed by yet a fourth earthquake hours later.
As I was writing this, a fifth earthquake just popped off!
Update: Now a sixth earthquake has gone off – this one though, way over on the western edge of the glacier area – lots of excitement today…
2nd Update: There goes number seven!
Having been monitoring the earthquakes at Katla since mid May, these seven earthquakes are the most in one day so far. This is just my observation as an interested independent amateur, and there is no evidence of swarming at this time (could this be the beginning of a swarm?), but it is interesting to note today’s occurrence. The situation would potentially warrant the term, swarm, if the number of earthquake occurrences continue at this pace or if it increases over the coming days, in my opinion.
Map source data captured from Icelandic Meteorological office – rolling 48 hour Seismicity map
(While tracking the Myrdalsjokull map and table, the Katla-specific earthquakes are differentiated by observing the map and longitude while ignoring those beyond approximately -19.45, which are over on Eyjafjallajokull)
We must keep our eyes on this potential disruptive volcano, Katla, that historically erupts following the eruption of Eyjafjallajokull (which first erupted April 14). Katla is about 10 times more powerful, and has the potential to cause worldwide disruption.
I’ve been keeping a map record of the Katla earthquake locations since 17-May. It is interesting to note the buildup of earthquakes on the East-Northeast rim area. Time will tell. Stay tuned…
Update, Saturday, 12-June
Apparently 3 additional earthquakes registered between yesterday and today as Katla remains shaky so far this morning as of 0730 Pacific Time. Then quiet for most of the day.
Update, Sunday, 13-June
Again, 3 additional earthquakes leading into this morning, although this time followed by a fourth – the past several days have certainly been the most active.
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Katla Volcano Update 21 May 2010
May 21, 2010, Submitted by: Ken
The earthquakes at the Katla volcano site appear to possibly be increasing in frequency as of this moment (time will tell however). Since May 17 there have been four earthquakes at or very near Katla, while a 5th just on the edge of the Myrdalsjokull glacier.
Although 4 or 5 earthquakes at the volcano site in 4 days does not indicate a drastic change in pattern, the interesting notation at the moment is the fact that the two most recent earthquakes occurred within 3 hours of each other on 21 May, 2010, at depths of 5km and 13km. That in itself is an increase in occurrence. It may be an anomaly, but it justifies keeping one eye on Katla, the big sister of Eyjafjallajokull.
What do these volcanic earthquakes tell us about what is going on at the Katla volcano?
One type of volcanic earthquake may indicate that changes are occurring due to magma moving in to an area of the rock which changes the pressure around it. At some point, the rock will break or move. If this type of earthquake becomes frequent, and a lot of earthquakes begin occurring or swarming (Earthquake swarms are when we suddenly start seeing clusters of earthquakes in the same general area over a relatively short period of time), it may be a precursor warning that an eruption is about to happen.
What we are seeing at Katla, in my opinion is NOT cause for immediate alarm, but it is noteworthy to observe this recent activity and to stay up to date with what is happening there.
There is something going on beneath the ice.
From 17-May-2010, Uh-oh! Katla Volcano Just Rumbled
Katla historically erupts following the eruption of Eyjafjallajokull (April 14), is possibly 10 times more powerful, and has the potential to cause worldwide disruption.
Earthquake Map Source: Icelandic Meteorological office – their maps show only last 48 hours, so I have kept a separate view to include the Katla quakes since 17-May-2010 as of this post date
Update 26-May-2010, 17:00 UTC, there have been 10 Katla earthquakes since 17-May-2010. Still no cause for alarm, however we are currently seeing about one per day. No real worries until we begin seeing more frequent events, such as the event that inspired this post, which has not occurred again as of this update.
STUNNING! Eyjafjallajokull Eruption Video
May 19, 2010, Submitted by: Ken
This amazing up-close HD quality eruption video of the Eyjafjallajokull volcano, is an exploding eruption of rock, magma, and ash thrown high into the sky, and displays the absolute stunning power of forces within the earth beneath our feet!
My take away after watching this, is that we are such tiny little creatures in comparison. To view and hear the power of this volcanic eruption in progress is awe inspiring. I can’t even imagine what the neighboring Katla eruption will be like (about 10 x stronger) having just watched this… !
Credit goes to it’s apparent owner, Chris Weber.
Once you’ve started the video, be sure to select 480p and then go full screen!
By Chris Weber from his channel on YouTube
