Volcano and earthquake activity in Iceland
According to Icelandic news it seems that Almannavaranir (Iceland Civil Authority) have cancelled the uncertainty level for Grímsfjall volcano. But the uncertainty level was put in place following the glacier flood from Grímsvötn glacier lake.
The announcement from Iceland Civil Authority in Icelandic. Please use Google Translate.
Óvissustigi aflýst vegna Grímsvatna (Icelandic)
Icelandic News. Please use Google translate.
Óvissustigi aflýst vegna Grímsvatna (Vísir.is)
I have seen a lot of people worrying about earthquakes and earthquake swarms that take place in Iceland on regular basic. Those worries are not needed as Iceland gets about one to two earthquake swarms on average over the course of one week. Most of the earthquakes that take place in Iceland are tectonic in nature. There are also volcano related earthquakes. But they can be spotted by there location in connection with the volcano in question (Katla, Grímsfjall, etc..).
The reasons for the earthquake swarms in Iceland is geological and is because Iceland sits on a rift zone. This can be shown clearly on this picture here.
Click on picture to get better resolution.
This map clearly shows all the zones in Iceland. In this areas most of Iceland earthquakes happens. But also a big part of Iceland earthquakes happen in areas like SISZ and TFZ.
On the normal week there are about 150 to 400 earthquakes in Iceland over the week. Most of them are in the size ML0.0 and up to ML2.8. Most week have one or two earthquakes that are ML3.0 to ML3.8 in size. On a quiet week there are about 50 to 100 earthquakes, most of them less then ML2.5 in size. When there is a busty week in Iceland the earthquakes numbers can easily go over 2000 and sometimes well over 5000 earthquakes. When that happens IMO doesn’t even bother in classifying and locating all the earthquakes that take place. But they are saved anyway in IMO database.
Picture taken from this blog: Earthquake in Iceland (2008); This blog has more images about the tectonic process in Iceland.
According to the news the glacier flood from Grímsvötn is subsiding and is expected to be over in the next two to three days. At the same time the harmonic tremor that started at 3rd of November 2010 is also subsiding. No clear reason is for the harmonic tremors.
Currently there is nothing that indicates that a eruption is about to start in Grímsfjalli. But that can change with a short notice, as Grímsfjall sometimes does not give a long warning before it starts erupting.
Icelandic News. Please use Google Translate.
Farginu létt af eldstöðinni (Vísir.is)
Hlaup í rénun (Rúv.is)
English news.
Flood waning, Iceland volcano eruption less likely (washingtonpost.com) – Thanks to Erik for this news.
According to news the glacier flood from Grímsvötn has peaked and is already dropping down. So far there has not been any volcano eruption. But harmonic tremor is still ongoing in Grímsfjall volcano and does not show any signs of stopping. But this harmonic tremor appears to be a bit fluctuating for some unknown reason.
Icelandic News. Please use Google translate.
Hlaupið að minnka (Rúv.is)
Vísindamenn í könnunarflugi (Vísir.is – Has video)
Hlaupið hefur náð hámarki (mbl.is – Has video)
Since 02:30 UTC on the 3rd of November 2010 there has been constant harmonic tremor in Grímsfjall volcano. It is currently unclear why harmonic tremors are happening at Grímsfjall volcano. But there have been some ideas that this might be because a small eruption has started at Grímsfjall volcano.
According to news from few moments ago (around 14:00 UTC) there are no signs of a eruption at Grímsfjall volcano at present time. But harmonic tremors continue at this moment like they have been doing since 02:30 UTC last night.
The possible reason why the scientists don’t see any signs of a eruption is because none are visible on the glacier at the moment. But until something appears on surface what is going on in Grímsfjall it is going to remain unclear what is going on at the volcano.
Icelandic News. Please use Google Translate.
Hlaup og órói í Grímsfjalli (Rúv.is)
Engin merki um gos (Rúv.is)
Gos gæti verið hafið (Vísir.is)
Könnunarflug yfir Grímsvötn: Engin merki um gos (Vísir.is)
Vísindamenn fljúga yfir Grímsvötn (mbl.is)
Engin ummerki um eldsumbrot (mbl.is)
International news.
New eruption could be looming in Iceland, experts warn (AFP)
Updated at 14:59 UTC on the 3rd of November 2010. News link added.
Updated at 15:22 UTC on the 3rd of November 2010. News link added.
Icelandic civil protection (Almannavarnir) have declared a uncertainty level over Grímsfjall volcano due to glacier flood coming from them. This level is the lowest level of warning that Almannavarnir have in case when there is a risk of dangerous events taking place.
At current time no eruption has started in Grímsfjall volcano. Note that this volcano is often called Grímsvötn in Iceland. But it is the same location with two names.
Almannavarnir announcement. Please use Google Translate.
Óvissustig vegna Grímsvatna (Icelandic)
Icelandic news. Please use Google Translate.
Almannavarnir lýsa yfir óvissustigi (Rúv.is)
Óvissustig vegna Grímsvatna (mbl.is)
Text updated at 19:47 UTC on the 1st of November 2010.
According to Icelandic news there is a good chance of a eruption in Grímsfjall. Following the glacier flood from Grímsvötn glacier lake. That is at least the opinion of Páll Einarsson, a geologist at University of Iceland. This is not going to be a big eruption in Grímsfjall in Páll opinion. But it is most likely going to be similar in size to the eruption in Grímsfjall in the year 2004. But no damage did happen from that eruption and it did not erupt international flight paths (just domestic ones). In the news Páll also says that the pressure inside Grímsfjall magma chamber appears to be slightly higher then in the year 2004. But otherwise the situation in Grímsfjall is almost identical to the one in the year 2004.
Icelandic News. Please use Google Translate where possible.
Miklar líkur á gosi (Rúv.is)
Rúv evening news on 31st of October 2010. Note: This link is going to die after two weeks as Rúv deletes older news streams from there web pages after that time.
Líkur á eldgosi í Grímsvötnum (mbl.is)
Meiri líkur en minni á gosi í Grímsvötnum (DV.is)
Text updated 2nd November 2010 at 20:11 UTC.
Few hours ago a glacier flood started from Grímsvötnum. But it was only confirmed few moments ago. The flood noise can be seen on following SIL stations around Vatnajökull.
Grímsfjall (increased noise)
Kalafell (increased noise)
This glacier flood is expected to reach it’s peak in about 4 to 5 days. If this is a repeat of the year 2004 events a eruption should start in Grímsfjalli in about 1 to 4 days from now. But if that plays out exacly like the year 2004 eruption remains to be seen. GVP has the eruption history of Grímsfjall here.
This glacier flood starts on the exact day as it did in the year 2004.
Icelandic news. Please use Google Translate.
Hlaup er hafið í Grímsvötnum (Rúv.is)
Hlaup í Grímsvötnum hafið (mbl.is)
Hlaup hafið í Grímsvötnum (Vísir.is)
According to the Icelandic news today geological scientists in Iceland are expecting a eruption and a glacier flood from Grímsvötnum at any time and without a any warning. But last week they did detect harmonic tremors on the SIL station that is on Grímsfjall volcano. It is not known if the harmonic tremors where created by water or by magma.
Currently the Grímsvötn lake is full and is ready to burst at any time without warning. Because of that scientists and Iceland Met Office have increased the monitoring of Grímsvötn and Grímsfjall volcano. It has been six years since the last eruption at Grímsfjall (2004) and it only where six years before that eruption (1998).
Iceland News. Please use Google translate.
Enn skelfur jörðin undir Vatnajökli (Rúv.is)
Búast við hlaupi hvenær sem er (mbl.is)
At 03:19 UTC there was a ML3.4 earthquake at 2,5km depth at Grímsfjall volcano according to the automatic SIL system that Icelandic Met Office has. This earthquake does not appear to be a after effect of the ML4.0 earthquake at Blöndulón few moments before that. Currently there have not been any other earthquake in Grímsfjall volcano. But that might change soon if this is a start of a eruption in Grímsfjall volcano. But it is going to take few moments to be clear on what is happening.
Currently there are no indicators that a eruption is starting in Grímsfjall volcano.
Update!
This earthquake was when reviewed size ML2.3 at the depth of 2.8 km.
Text updated at 14:40 UTC on the 31st of October 2010.
