Category: Earthquakes

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Large earthquake swarm in Krísuvík volcano

After four days of continues earthquake activity it appears that Krísuvík volcano has stepped up it’s activity by a order of magnitude. Since midnight there have been over 400 earthquakes in Krísuvík volcano. The activity is continuing when this is written and does not show any signs of slowing down at this moment. Geologist in Iceland are expecting more earthquakes in this area over the next hours and even earthquakes that are larger then ML3.0 in size.

The largest earthquakes where ML3.3 and ML3.7 in size. This is automatic size by the SIL system. The depth of the earthquakes was 4.7 km and 1.1 km according to the automatic SIL system. Due to high number of earthquakes the SIL system is putting earthquakes down all around the Reykjanes Peninsula. While there might be some earthquakes there, the number is not nearly as high as can be seen on the map. The earthquakes can be located by there low quality number.

Given the location and how this earthquake swarm is behaving it is my opinion that this is due to a magma is pushing up the crust in this area. But it remains a question of this is going to start a eruption or not. But the chances are growing for as long as this earthquake pattern holds up in Krísuvík volcano. If a eruption starts in Krísuvík volcano it is going to one of Hawaii type eruption, unless it is under water then it is going to be explosive for as long there is water getting into the crater. Last time there was a eruption in this area a 25 km long eruption fissure did form.

For now however all that can be done is to wait and see what happens. This earthquake swarm is going to continue for the next few hours and even days. The largest earthquakes can be seen on my geophone sensors here.



Map of the earthquake swarm in Krísuvík at 15:00 UTC. Picture is from Icelandic Met Office web page. Copyright belongs to them.

Icelandic news about this earthquake. Use Google translate at own risk.

Búist við áframhaldandi virkni (Rúv.is)
Engin merki um gosóróa (Rúv.is)
Heldur rólegra síðasta hálftímann (Vísir.is)
Jarðskjálftinn var 4 stig að stærð – 200 skjálftar frá miðnætti (Vísir.is)
Jarðskjálfti í Reykjavík (Vísir.is, 09:13 UTC)
Hætta á fleiri skjálftum (mbl.is)
Skjálftinn var nær höfuðborgarsvæðinu (mbl.is, 11:00 UTC)
Jarðskjálfti í Reykjavík (mbl.is, 09:07 UTC)
Skjálftinn líklega 4 stig (mbl.is)
Kort af skjálftanum (mbl.is)
Dregið hefur úr skjálftahrinunni (Vísir.is)
Tveir snarpir jarðskjálftar 24 km SSV af Reykjavík (DV.is)

Note: Check time stamps of the news articles.

Blog post updated at 14:50 CET on the 27.02.2011.
Blog post updated at 16:14 CET on the 27.02.2011.

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Two day long earthquake swarm in Krísuvík volcano

While this earthquake swarm in Krísuvík volcano does not appear to be big in size. It is clear that was rather long and might even be ongoing. But it is interesting how long this earthquake swarm did last. So far the time is about 2 days. It is impossible to know if the earthquake swarm is over or not. Current number of earthquakes is about 60 earthquakes so far.


Picture is from Icelandic Met Office graphic web tool.

The earthquakes are on North-South fault line according to the visual evidence. Depth of the earthquakes is from 12 km and up to 3 km at the moment. It is hard to know at the moment if this is due to magma inflow under Krísuvík volcano or just normal tectonic activity along the rift zone in Reykjanes.

Icelandic news about this earthquake swarm.

Hrina smáskjálfta í Krýsuvík (Vísir.is, Icelandic)

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A ML2.3 earthquake in Grímsfjall volcano

A earthquake with the size of ML3.3 ML2.3 took place at 01:19 UTC in Grímsfjall volcano. At the current moment no other earthquakes have been spotted following this single event. It is also remains unclear at the moment if this is a start of a eruption in Grímsfjall volcano. But at the moment there is nothing that indicates that a eruption is about to start in Grímsfjall volcano. But that can change with out any warning at all.

Note that EMSC is reporting this earthquake with the size of ML4.3. It is unclear at the moment what is the correct size for this earthquake.

Text updated at 11:40 CET on the 25th of February 2011. EMSC did change it down to ML3.3 size.
Text updated at 22:57 CET on the 25th of February 2011.

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Human made earthquakes in Hengill volcano

It appears that operations of Orkuveita Reykjavíkur are creating the earthquake swarms that have been seen in Hengill volcanoo. But as part of operations in Hengill geothermal plant they pump down cold water into the bed rock under considerable pressure. This is according to Sigþrúður Ármannsdóttir a geologist at Icelandic Met Office. But Vísir.is quoted here on this earthquakes swarms in Hengill volcano.

This type of earthquake swarms are going to repeat them self for as long Orkuveita Reykjavíkur is pumping down cold water into the bed rock in Hengill volcano. As the water creates a pressure change in the surrounding rock.

The most intresting earthquakes that happened as because of this swarm where 3.8 km NE of Hveragerði. But the size of that earthquake was ML2.6 (automatic size). and it was considerable distance from Hengill volcano and appears to have been triggered by the earthquake swarm in Hengill volcano (unclear however and just my own observation).

News about this.

Orkuveitan framkallar jarðskjálfta í Henglinum (Vísir.is, Icelandic)

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Small earthquake swarm in Krísuvík volcano

Currently there is a small earthquake swarm in Krísuvík volcano. This earthquake swarm is small and is only about 20 or so earthquakes at current time. It is impossible to know if this earthquake swarm is going to continue or grow at present time. But it is not uncommon in this area for a small earthquake swam to be a warm up for a larger one. But as always there is just a wait and see what happens in the area.

The largest earthquakes in this earthquake swarm have reached up to ML2.0 in size so far.

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Earthquake swarm at Upptyppingar

I notice that there is a small, yet growing earthquake swarm taking place close to a small mountain named Upptyppingar. This mountain is within the fissure swarm of Kverkfjöll volcano but the area is in it self not active volcanically.

Few years ago (2007) there was a earthquake swarm in this area that did have something about 2000 earthquakes over a 48 hour period. The reason why there is earthquake activity in this area is due to magma being pushed up into the bedrock below. This process is something of the same that took place before the Eyjafjallajökull volcano eruption. But with the major difference that here is no central volcano doing this.

Earthquake pictures from IMO from that time. No map sadly as I forgot to save them or they are stuck on my main computer that holds all my geological data.

Text updated at 03:28 CET on 18.02.2011. Minor error fixes in the text.

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New earthquake swarm in Hengill volcano

A new earthquake swarm has started in Hengill volcano. This earthquake swarm is in the same location as a earthquake swarm that took place there few weeks ago (see here).

So far this earthquake swarm has mostly been made out of small earthquakes. But all earthquakes are below ML2.0 in size so far.

It is unclear why this earthquake swarm is taking place. But the reason might be that the geothermal power plant that is in the area is pumping down or up ground water.

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Continued quiet time in earthquakes and volcanoes

It seems that the quiet time continues in Iceland. Besides small earthquakes swarms in Pesthnjúkar volcano and small earthquake swarm in Hengill volcano, there was also a earthquake swarm in Bárðarbunga volcano that did get into the world press. Other then this it has been quiet and no volcanoes have been showing signs of starting a eruption soon.

It is all quiet in Iceland, so not a lot of activity updates coming from me at the moment. But I hope to write soon a information post about one of Iceland volcanoes or earthquakes zones to pass the time.

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Earthquake swarm in Presthnjúkar volcano (Langjökull glacier)

A earthquake swarm of 70 something earthquakes have been taking place close to Presthnjúkar volcano in Iceland. This activity is tectonic in nature and is because of the rift zone. This volcano is located close to south end of Langjökull glacier, but Langjökull glacier covers two volcanoes (north Hveravellir and south Presthnjúkar). One at the north end and a other at the south end. This volcano last erupted in the year 3500 BC (?) according to GVP.


Picture is from Icelandic Met Office web page. Copyright belongs to them.

The earthquake swarm in south Langjökull volcano.

Earthquake swarms are common in this area and happen regularly. But last large earthquake swarm in this area was in June 2009. The largest earthquake that did happen today was felt in nearby area according to Icelandic news.

Icelandic news about this earthquake swarm. Use Google Translate at own risk.

Skjálftahrina á milli Langjökuls og Þórisjökuls (Vísir.is)
Jarðskjálftahrina í Langjökli (Rúv.is)