Posted on by Jón Frímann

Earthquake swarm in progress in Krýsuvík volcano

Today (18.08.2012) at 15:52 UTC an earthquake swarm did start in Krýsuvík volcano. So far this swarm is not big. With the largest earthquake having magnitude 1.8 according to automatic size. It is impossible to know at this point if this earthquake swarm is going to be strong, or has just ended. So far earthquake activity continues with minor earthquakes.


The earthquake swarm in Krýsuvík volcano. Copyright of this image belongs to Icelandic Meteorological Office.

If the earthquake activity picks up. I am going to do my best to update this blog. But I am on limited 3G internet connection. So it might be a while until update takes place.

7 Replies to “Earthquake swarm in progress in Krýsuvík volcano”

  1. Dear Jón,

    IMO has changed the magnitude from 3.8 to 1.8 and back to 3.8; it seems they don’t know what to make of it. Meanwhile there haven been more quakes (0.8, 1.8, etc.) on exact the same spot, 8.7 km ENE of Godabunga. What could this mean?

    Regards,

    Henk

    1. Considering the depth, I would assume that the detectors picked up a considerable crack in the glacier or something like that. But this would mean that it is not an earthquake by definition. I guess they have to filter out how much of the energy was actually released into the hard rock (counting as an earthquake).

    2. The minor earthquake activity is normal following such large earthquake in Katla volcano caldera. More earthquake activity should be expected. I have not noticed any changes in estimate of the earthquake size on IMO web page. But I normally do not monitor there new pages. I normally use there old web page, as I find it better.

  2. My wife and I are holidaying in Hafnafjorður and were hiking today (Sat 18.08) about 10km from where the swarm occured. We went to Seltun at around 16:00-16:30 where the swarm seems to be centered. We felt nothing during our hike or while at Seltun. However we had visited Seltun just under two weeks ago and today things definitely felt very different. The fumarole at the top of the Seltun complex seemed to be steaming a lot more than it was two weeks ago while the fumaroles at the base of Seltun had virtually no steam coming out of them, yet two weeks ago the situation was reversed. The ones at the bottom were steaming madly and the fumarole at the top was hardly steaming. The mud hole across the road was a gultenous porridge like boiling mass two weeks ago, bubbling away. Today it had completely liquified and had the consistency of watery youghurt with absolutely no steam issuing from it….quite dissappointing. Much more strangely, two weeks ago there were a large group of Horses in the field opposite Seltun who were demonstrativly exhuberant and friendly. When we approached the fence at their field they all rushed over to us to greet us and “hang out with us” for a while. Today however they held back way into the field and totally ignored us, refusing to approach the fence. One or two of them looked like they wanted to approach us but something was holding them back….. we just put it down to them being stand offish….which has definietly not been our experience of Icelandic Horses who seem to crave human companionship at every opportunity. On the way back I thought that the shoreline of Kleifarvatn looked odd. It had some crescent shaped sandbanks exposed just at the shoreline which I hadn’t noticed two weeks ago or even on the journey up to Seltun today…but they may well have been there all along and I just happened to notice them on the journey back.
    However although I felt nothing physically I was definitely aware that something just wasn’t right at Seltun. I hasten to add that I was totally unaware of any sismic activity until I looked at the Icelandic Met Service website a few hours later. I wanted to see if anything had happened with Katla…so I was stunned to see that there had been an earthquake swarm at Krýsuvík.

    1. You would not feel such small earthquake swarm. Even if you where standing on top of it. Hot springs and hydro-thermal features can change without any warning. So seeing something dead in hot springs that alive few days ago is not something uncommon.

      I don’t know about the horses. Maybe they where just not in the mood.

  3. You can only feel an earthquake if it’s at least a minimum 2.5, or better still a 3.0. And for these you should be right near the epicenter. You don’t feel earthquakes of magnitude 1.0 or 1.5, even if you are right on the top of them, unless they would be very shallow.

    Kleifarvatn keeps changing every few years since the earthquakes in 2000. After those, it reduced dramatically in size and exposed the hot springs on the bottom of the lake. Then, a few years later it filled again. Last year it was pretty much dry and exposing the hot springs again, but this year it has been full again. It seems that this behavior correlates well with increasing swarm activity and inflation/deflation of the volcano.

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