Category: Geology

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Landslide in Fljótsdal, east Iceland

Yesterday (1-June-2014) a 300 meter wide landslide fell in east Iceland. This landslide did create minor damage for the nearby farm. The total damage is so far 250.000 ISK (1.615,93€, 1.312,13 GBP current exchange rate). The farmer thinks that at least one sheep was lost under the landslide, it is not told of any lambs where lost, 500 poles for fences where also lost under the landslide. This farmer makes them for sale. Four horses did safe them by jumping over a fence when the landslide got close to them.

The reason for this landslide is melting of snow the mountain above the farm. Summer melt has now started in Iceland and for the past few days have been warm in Iceland with temperature going up to 18C (and above) at locations. There has not been a lot of rainfall in Iceland for the past few days.

Icelandic news of this landslide

Aurskriða féll í leysingum í Fljótsdal (Rúv.is, Icelandic, Picture)

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Fossil of a tree found in road tunnel work

A long time a volcano erupted in Iceland. This volcano spewed out basalt lava field (Hawaii style). This lava did flow over a forest that was nearby and killing all the trees in it. Few weeks ago and several million years later and few kilometres down the remains of this forest was found. Since one of the tree did fossilize in the lava. As the tree was engulfed in the lava it did turn to charcoal that was later removed by water and leaving the empty imprint of the tree in the bedrock.

The remains of the tree are now clearly visible in the road construction tunnel. The hole after the tree is full of water and part of it has been removed by the tunnel digging. Picture of it along with news can be found in the link below.

Fossil of a tree found in tunnel construction

Far eftir trjábol í Vaðlaheiðargöngum (Rúv.is, Icelandic, Picture)

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Risk of landslides in north and east Iceland at the moment

It is worth pointing out that Icelandic Meteorological Office has put out a warning for landslides in north and east Iceland due to spring melt water and heavy rain on top of that.

There have already many landslides taken place in north and east Iceland, many of the blocking roads and damaging them in the worst cases. Along with creating damage to power lines in few rare cases. Any travelers in north and east Iceland should at least keep a eye out for landslide risk if they are going up in Iceland. Due to heavy snow highland roads are still closed, please see Iceland Road administration road conditions web page for more details, it is in Icelandic and can be viewed here.

There is also a considerable risk of ice-dam formation in Iceland at the moment, when it breaks a flood follows and those floods can be dangerous to both people and animals.

For pictures and videos of the landslides, please see the Rúv news coverage below. It is in Icelandic.

Aukið rennsli sést utan úr geimi (Satellite pictures)
Vatnavextir valda tjóni (Pictures)
Enn falla skriður á Norðurlandi (Pictures)
Lokað um Köldukinn fram yfir helgi (pictures and a video, road closed news)
Enn talin hætta á skriðuföllum í Köldukinn (Picture, risk of more landslides)
250 metra aurskriða tók veginn í sundur (picture, video of a large landslide)
Þjóðvegur 85 lokaður (road 85 closed, picture)
Stórt krapaflóð í Fljótsdal (flood due to ice-dam, video, pictures)

Blog post updated at 22:12 UTC on 05-June-2013.

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Few words on my geophone network

I run a small geophone network in Iceland. This geophone network won’t be getting any bigger any time soon. I have two reasons for that statement. I cannot get hardware that I need to build my geophone network. The main part remains out of stock, the geophone. I have also come to releases that after about 10 years time I won’t be able to run the geophone network anyway. But my plan is that in about 10 years time I am going to move to the Falklands Islands. Based on distance, cost and such factors. It is going to make it impossible for me to run an geophone network at that distance. It is going to take me 10 years to assemble my plan and get the funds before I can move to Falklands Islands. During that time I am going to be living in Denmark.

I have been running the current geophone network, in one or other form since the year 2006. So that is already 6 years. This has not been easy task. With hardware failures, software failures, internet failures and other issues that I have had to deal with during this time. But I have managed to keep the system running during that time, with help of the people how are hosting it for me at location. I am always thankful for that help.

I am however just going to close the geophone network in Iceland after 10 years. Closing at one place means that I can open up at new place. That place is going to be in Falklands Islands with time. As I need time to set-up new geophone network. Along with solving connection issues and such things. Setting up new geophone network in Falklands Islands might take up to 5 years for me. Depending on connections and such. As I might have to set-up my own radio links (I just expand my lan into such radio links on 2.4Ghz). Since ADSL speeds are expensive and have limited data quota are included with the subscription (the largest is just 3,3GB for 1 month), along with limited mobile coverage in Falklands Islands. But this is just really early planning. The details are going to get shorted out when I move there after 10 years or so.

I however think it is good to run my own geophone network for more then 10 years (oldest parts of the geophone network have then been running for up to 16 years in the year 2022) on my own. I am not sure. But I do not think many people in the world are doing this as I am. But I might be wrong on this.

Hardware that I can buy in the future

With the future lack of geophone for me to buy. I have several options on what hardware to buy so I can record earthquakes. First of is the cheap SEP seismometer. But that is a long period seismometer with period up to 20 seconds. Good for detecting earthquakes more then 2000 km away. My second option is to by a digital seismometer that is called VolksMeter. But that is also a tiltmeter. But VolksMeter seismometer is expensive (while I am broke at least). They cost $1245 single channel and $1795 dual channel. This is without GPS, power supply and such things. Based on this prices. I am not going to buy VolksMeter seismometer any time soon.

Blog post updated on 28.09.2012 at 04:45 UTC.

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Large landslide in north Iceland

Few days ago an large landslide did happen in north Iceland. This landslide did come from the mountain Móafellshyrna. It has been estimated that this landslide is about 300 meters wide and is about 1 km long. Rocks continue to fall from the mountain. Some are large as houses in some areas. So going up close to this landslide is not save for the moment.

It is believed that mixture of earthquake activity in Tjörnes Fracture Zone along with rain and melting snow is the reason for this landslide.

Icelandic news about this

Drunur í björgum við Þrasastaði (Rúv.is, Icelandic, Pictures)
Gríðarstór skriða (Rúv.is, Icelandic, video)

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Katla volcano geology and features

Here is a short blog post about the geology and the features of Katla volcano. This article is based on science and my knowledge of Katla volcano. It might not be error free and up to date. But I do my best in that regards. But as I cannot afford to buy published or subscribe to web pages that publish science articles about volcanoes in Iceland. I do my best with what I can get for free online (that is often some amount of articles). So my information might be outdated, or might have been replaced by new research that I might not know about. But I use peer-reviewed articles when they are available to me.

Evolution of Katla volcano

Katla volcano is an caldera volcano. It formed in the classic way the caldera forms. The formation of Katla volcano took place around before Holocene, but the data that is available in sediments around Katla volcano only go far as ~8400 years. So it is unknown when Katla volcano formed. Instead of water. Katla caldera has glacier that is from 300 to 740 meters thick where it is thickest. For comparison, Hofsjökull volcano glacier is around 650 meters thick where it is thickest (from what I have read, newer studies might have changed that assessment). The exact age of Katla volcano is currently unknown, but it has been suggested that it is of Pleistocene age (2.6 ma to 11,700 years). The shape and form of Katla volcano during this time period is also unknown today. It is also believed that Eyjafjallajökull volcano is considerable older then Katla volcano. But Eyjafjallajökull volcano is among Iceland oldest volcanoes. Being around 750000 years old according to studies into it.

Katla magma chamber and activity

Katla magma chamber goes trough evolutionary changes every 4000 to 6000 years according to estimates and data gathered by scientists. In the past 12000 years, since last ice age it has gone trough that process twice. But this means current set of magma pluming inside Katla volcano is not going to last for more then few thousands of years at best. I do not know exactly what this changes in Katla volcano pluming mean in terms of eruption. But I find it most likely to be nothing in real terms. It has been noted with study into geological past of Katla volcano that it experiences period of high and low activity. Katla volcano has high and low in it’s eruption activity. Based on data from the past 12.000 years. Currently Katla volcano is having a low period activity. That means fewer eruptions with long quiet time between them. As has been the pattern for the past 1100 years or so. This is according to survey data on activity in Katla volcano for that time period. I do not know if changes in Katla volcano magma chamber influences this low and high period of volcano activity in Katla volcano.

Katla lava

Katla volcano erupts basalt lava normally. On extremely rare occasions Katla volcano erupts magma that is andesite in nature. But that is really rare occurrence in nature. I expect next eruption in Katla volcano to be basalt in nature. But no lava is going to flow due the glacier that is on top of Katla volcano. But that is going to create an ash cloud that is not so different from Grímsfjall volcano ash cloud seen in the May 2011 eruption. As the magma in the two volcanoes are mostly basalt in nature. But that maks for darker but also more large ash particle (less small ash particles). So the ash cloud is not going to create the same problem as Eyjafjallajökull volcano ash cloud did in the year 2010.

Reference articles

Katla volcano, Iceland: magma composition, dynamics and eruption frequency as recorded by Holocene tephra layers (2007)
Bergrún Arna Óladóttir & Olgeir Sigmarsson & Gudrun Larsen & Thor Thordarson

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Quiet days in Iceland geology

Over the past days there have been a quiet streak happening in Iceland geology. This regularly happens and doesn’t mean anything special. This quiet times can sometimes last for up to 10 to 20 days at the longest. The longest quiet time that I did see lasted something close to five weeks. But then activity started to pick up again slowly.

It also happens sometime that quiet period is end with a bang. Then with a ML/Mb 4.0 or 5.0 earthquake and following earthquake swarm. Even if quiet time happens in Iceland sometimes, it does not necessary mean that the year is going to be a quiet one. As we have already seen with Eyjafjallajökull eruption in 2010.