The magma below Upptyppingar tuff mountains

Upptyppingar are a tuff mountains in the east highlands in Iceland. There formation is contributed to a sub-glacier eruption in this area around 12.000 years ago. A second older sub-glacier eruption feature is also present in this area, it is called Álftadalsdyngja. It is believed that it did form around 700.000 years ago in a basalt eruption in this area. Upptyppingar and Álftadalsdyngja are both inside Kverkfjöll volcano fissure swarm.

Map of the area. Copyright of this picture belongs to how created it. Author unknown. Picture is from here.

In the year 2007 (Week 50) a earthquake swarms started to appear in Upptyppingar area. Earthquake activity in Upptyppingar area have continued since then. With total number of earthquakes in this area since the year 2007 is something over 6000 total. The reason why earthquakes are happening in this location is because magma is pushing up trough the crust in this area. This has been confirmed by GPS measurements since the year 2007.

It is my opinion that increased activity in Askja volcano might trigger a eruption in Upptyppingar area or in nearby area. As the risk of dike intrusion from Askja volcano into the Upptyppingar magma sill might trigger a large fissure type of event in this area. This is just speculation based on observed data. So please take note of that fact. The reason why I fear dike intrusion from Askja volcano is due to the changes that Upptyppingar magma has created in the nearby crust. But if this happens depends on how Askja volcano eruptions are going to behave in the future.

Here are some scientific data on Upptyppingar and the magma that has been collecting at 15 km depth below Upptyppingar mountains since the year 2007.


Location of the earthquakes since the year 2007. Copyright of this picture belongs to Icelandic Met Office. Picture is from here.

Depth of the earthquakes in the year 2007. As can be seen, the magma moved upwards with time. Copyright of this picture belongs to how created it. Author unknown. Picture is from here.

Estimated location of the magma below Upptyppingar mountain. This location is based on earthquakes and other measurements. Copyright of this picture belongs to how created it. Author unknown. Picture is from here.

What happens with Upptyppingar is now just a question of waiting and seeing. But there is also a good chance that this magma is never going to reach the surface in a eruption and is just going to cool down there and form a basalt dike that is going to be exposed in few million years when the weather and ice remove the rocks on top of it.

Interesting earthquakes 20 km WSW of Laki in Eldgjá volcano canyon (Katla volcano fissure system)

There are interesting earthquakes about 20 km WSW of Laki. The locations of the earthquakes suggests strongly that they belong to Katla volcano fissure system. Last eruption in this area took place around the year 934. When the Eldgjá volcano canyon was formed. That eruption did destroy a older volcano canyon located in this same area (lava flows volcano ash did fill up that canyon far as I know).

The earthquakes that have been taking place in this area are small. The largest so far has the automatic size of ML1.2, but only ~4 earthquakes have been recorded so far. But what is most interesting about this earthquakes is the depth. The earthquakes that has the best automatic detection by the SIL system has the depth of 0.7 km. But that makes the depth of ~700 meters and that is a shallow earthquake. Given that this area has only fissures and no activate volcanoes. It is not unheard of in Iceland that a fissure eruption to start with no warning at all. Last time this did happen was in Gjálp eruption in the year 1996. Before that a dike intrusion into the bedrock did manage to get to the surface in Askja eruption in the year 1878, when a 25 km long volcano fissure did open up (small compared to Eldgjá eruption around the year 920).

I do not know what is going on in this area at the moment. As the activity so far has been too small to make any clear picture of it. But Katla volcano is a big volcano and it is not out of volcano league to make a new fissure eruption instead of the regular caldera eruptions under the glacier as Icelanders have gotten used to over the past 1000 years or so. Last time this did happen there are suggestions that there was a also a eruption at the same time in Katla volcano caldera. But that this has only been revealed during research over the past 50 years or so in this area.

I have also noted that there is a small increase in earthquakes inside Katla volcano caldera, not far from Austmannsbunga. But at this moment it is too early too know what it means for sure. There is no eruption is imminent in Katla volcano when this is written. Just too be clear on that fact.

Update on the crack in Þingvellir (Thingvellir), Almannagjá fissure

Tonight Rúv did have a news about the fissure that did open up in Þingvellir (Thingvellir) few weeks ago. Now scientists have started to explore this new fissure. So far they have measured that it is about 10 meters deep. It is still unclear how long it is. The current theory is that this new fissure started to open up after the Mw6.8 and Mw6.7 earthquakes in SISZ in the year 2000, or the Mw6.3 earthquake in the year 2008. But that is however unclear at this time.

What appears also to have happened is that ground water have cleaned out loose material in this new fissure. This might possibly have deepened the fissure. But this aspect of this new fissure is still a bit unclear one. But what is the most amazing thing is that the road has not started to collapse earlier then it did. Due how big this new fissure appears to be.

News on Rúv about this. Use Google translate at own risk, as Google does not know what Icelanders are saying.

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