Category: Magma

This article is going to be updated as needed.

Since yesterday (30-September-2016) Katla volcano has been quiet. For the last 24 hours no major earthquakes (above magnitude 3,0) has happened. Only few minor earthquakes have happened in this period and almost all of them where less then magnitude 2,0 earthquakes. Only two earthquakes had the magnitude above 2,0 and none above 3,0.

The earthquake map of Katla volcano for the last 48 hours. Copyright of this image belongs to Icelandic Met Office.

Conductivity in Múlakvísl glacier rivers continues to be high and the glacier river has unusual low amounts of water in it. When this is written the value has dropped down to 104 µS/cm from the high of 221 µS/cm. The folk tale for this are is that sometimes Múlakvísl glacier river goes dry just before an eruption. I don’t know if that phoneme gets confirmed or not when a eruption starts in Katla volcano.

The reason for this earthquake activity in Katla volcano is due to magma trying to push it self to the surface from depth. If experience is anything to go by it is clear that current activity is not over, even if there is a drop in activity at the moment. I’ve seen this type of drop in activity before, few hours before the eruption (the first one) in Eyjafjallajökull 2010 and in Bárðarbunga volcano 2014. The lack of earthquake can have many reasons behind it. The magma might now be flowing without a resistance, the pressure has equalised for the next few hours (if that time is not running out already) or something else. Currently all that can be done is to wait and see what happens next.

Streaming web cameras of Katla volcano

Here are two streaming web cameras for Katla volcano.

Rúv live web camera of Katla volcano.
Live from Iceland web camera of Katla volcano.

Storm warning for Iceland Sunday to Monday

On Sunday and Monday there is going to have strong storm in Iceland with wind gusts up to 40m/s in south Iceland to start with. Heavy rain is going to follow this storm according to the weather forecast at the moment.

Article updated at 22:16 UTC. Links to live cameras of Katla added.

This article is going to be updated as needed today (30-September-2016).

During the last 48 hours total of 261 earthquake has happened in Katla volcano when this is written. Largest earthquakes during the last 24 hours have the magnitude of 3,1 and 3,2. The largest earthquake had the magnitude of 3,6. Since there is no eruption currently there has not been any change in the harmonic tremor.

The earthquake activity in Katla volcano. Copyright of this image belongs to Icelandic Met Office.

The current earthquake activity started in end of August with the magnitude 4,5 and 4,6 earthquake activity. After doing a short review of the earthquake during this period I did see it. During this period the earthquake activity has been constant, but at lower lever then it is currently. There is now in my view a good chance that this is going to end in a eruption. It might not happen, but the odds are less in that outcome at the moment. Earthquake activity is pulsating, I don’t know why that happens. Same pattern was seen in Bárðarbunga volcano last year when magma was pushing it self through the crust until an eruption started. Currently the alert status for Katla volcano is green. Information can be found here.

Next update is going to be a few hours or soon as something interesting happens.

Update at 12:42 UTC

Colour code for Katla volcano has been upgraded to Yellow. Map can be found here.

Update at 15:35 UTC

When this is written the activity in Katla volcano has quieted down a little. This has happened several times during the last 48 hours so it might not mean anything. Large earthquakes happened at 12:07, a magnitude 3,6 and at 12:09 a magnitude 3,6. Earthquakes at 12:10 and 12:13 UTC where both magnitude 3,2. Some of the largest earthquakes have been felt in nearby populated areas (farms, not felt in Vík í Mýrdal far as I know). No harmonic tremor has been detected and that means an eruption has not yet started.

Green stars show the earthquakes with magnitude above 3,0 in Katla volcano. Copyright of this image belongs to Icelandic Met Office.

The current earthquake activity is now showing up in a area that has the direction North-East and South-West. Suggesting that magma might break up in a fissure at this location if it can break up trough the crust. The other possibility is always that this just stops and nothing more happens. I’m not sure if that is going to be the result now.

Update at 19:06 UTC

Uncertainty level has been declared for Katla volcano and nearby area.

Update at 23:06 UTC

The road to Sólheimajökull glacier has been closed by the police until the current situation is over in Katla volcano. Currently the rate of earthquakes is low but earthquakes do continue to happen in the same area as before.

The earthquake activity in Katla volcano. Green stars are earthquakes with magnitude above 3,0. Copyright of this image belongs to Icelandic Met Office.

While the activity has slowed down the for moment I don’t think this is over, at least not until the earthquake activity completely stops for a long period of time. Currently the earthquake activity is back to the levels it was on after the magnitude 4,5 and 4,6 earthquakes on 29-August-2016. It might increase again without warning.

Article updated at 11:00 UTC. Added missing links.
Article updated at 12:42 UTC. Update added.
Article updated at 15:35 UTC. Updated added.
Article updated at 19:06 UTC. Updated added.

This is going to be a short article, as the current situation is constantly changing.

Earthquake swarm started around 03:00 UTC (29-September-2016) in Katla volcano, this earthquake swarm has been heavy due to high number of earthquakes, when this is written around 88 earthquakes have been recorded in Katla volcano. This number is going to change as the earthquake activity continues.

The earthquake activity in Katla volcano. Copyright of this image belongs to Icelandic Met Office.

According to a statement that Icelandic Met Office issued the conductivity in glacier rivers from Katla is higher than normally during this time of year. At current it is 190uS and according to the Icelandic Met Office this is not normal during this time of the year. At the present no harmonic tremor has appeared, if it appears it is going to be clear on the SIL stations around Katla and maybe good distance away from the volcano. As it is going to override any background noise that might be happening (wind, noise, traffic).

This article is going to be updated as I learn more.

Update at 19:00 UTC

The earthquake activity has continued today as before, there have been small drops in activity for up to a hour, after that the earthquake activity continues. Currently (when this is written) there is a low in the earthquake activity. Largest earthquake was at 16:28 UTC and had the magnitude of 3,0. Other earthquakes have been smaller in magnitude.

The earthquake activity at 18:45 UTC. Copyright of this image belongs to Icelandic Met Office.

Update on earthquake area location

Most of the earthquake activity today (29-September-2016) has been taking place north of cauldron 16 (see map). This makes it less likely to be connected to hydrothermal area and changes in that type of area. Since hot-springs create the cauldron seen in the Mýrdalsjökull glacier, the heat melts the bottom of the glacier and creating glacier outburst once in a while. It does appear that the earthquake activity has extended it self into cauldrons 10 and 11 and maybe cauldron 16, but I’m not sure on that detail currently.

Earthquake activity in Katla after the year 2011. Cauldrons are marked with numbers and location on this map. Copyright of this map belongs to Icelandic Met Office. Source link.

Article updated at 16:05 UTC. Time corrections on when this activity started.
Article updated at 19:00 UTC. Updated added.
Article updated at 19:47 UTC. Map added from 2011.

Today (26-September-2016) an magnitude 3,9 earthquake took place in Katla volcano caldera. This earthquake had the unusual depth of 0,0 km (error margin is around +-200 meters or more). This was the largest earthquake in a earthquake swarm that started yesterday (25-September-2016). It has for the past 48 hours been slowly increasing in magnitude and size. Most of the earthquakes where smaller than 1,0 in magnitude. Few magnitude 2,0 (and larger) earthquakes took place today in Katla volcano. In total 30 earthquakes have so far taken place in Katla volcano during the past 48 hours.

The earthquake activity in Katla volcano. Copyright of this image belongs to Icelandic Met Office.

This earthquake swarm and the largest earthquake happen slightly south of the area that had the magnitude 4,5 and 4,6 earthquake swarm almost a month ago (article can be found here). This same area was also active month ago, but only with minor earthquakes. What this pattern suggests is that possible two or more fissures might open up inside the caldera once it erupts. The east-west fissure might be up to 10 km long and south of it a fissure that is up to 5 km long might open up. This is only my view and only speculation, but I cannot ignore the fact that this earthquake swarm activity is lining up in interesting way and that highly suggests that a fissure or a rift process has started in Katla volcano. If it continues or stop is impossible to know.

During documented history (~1000 years) Katla volcano has had most eruption during the period of July until end of November. With few eruptions taking place in January and February. There are huge gaps in this information due to historical inaccuracy, lost information and so on. As before, there are no clear signs of eruption being imminent, but I got the feeling that its not long now, at least less than 10 years until an eruption in Katla volcano.

Article update at 22:11 UTC on 27-September-2016. Minor spelling fixes.

Today (19-August-2016) a magnitude 3,5 earthquake took place in Katla volcano. It was followed by several earthquakes, both before the strongest earthquakes and after it.

The earthquake activity in Katla volcano. The green star shows the location of the magnitude 3,5 earthquake. Copyright of this image belongs to Iceland Met Office.

This doesn’t seems to be an activity connected directly to magma movements. This might however be a gas under pressure breaking rock, since clues this summer suggests that heat is now increasing in the caldera. At least for now, it might cool down again in coming months. The most common months for Katla volcano to erupt are from July until November, eruptions in other months are less common, they do happen every few hundred years.

The magnitude 3,5 earthquake as it appeared on my geophone in Heklubyggð. This image is under Creative Commons licence. Please see the CC Licence page (above) for more details.