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.
Earlier tonight a second harmonic pulse was seen on Grímsvötn SIL station. This time the harmonic pulse has lasted longer and is still ongoing when this is written. What is creating this harmonic pulse is unclear at this moment. But at current time Grímsvötn lake is full of water. It might well be that the water is on the move and is leaving the Grímsvötn lake. However it is not going to be clear if that is the case or not in the next few hours. I would not be surprised if it goes both ways. That is the water is on the move and that it might not be on the move at all.
The second harmonic tremor seen on SIL station run by the IMO. Picture credit, Icelandic Met Office.
Grímsvötn SIL station. Click here for the full list of SIL station run by Icelandic Met Office.
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Today around 13:00 or 14:00 UTC (not sure exactly when) there was a possible minor harmonic tremor at Grímsfjall volcano. But earlier today I did write about the fast rise that is happening at Grímsfjall according to GPS data. It seems that things might get interesting soon if the current trend continues as it has for the past few weeks.
I do not believe that this is weather interference that I am currently seeing.
Possible harmonic tremor pulse seen at Grímsvötn SIL station on 2.October 2010. Image from IMO web site
Text updated at 16:25 UTC 2. October 2010.
According to GPS data from IMO (automatic data). It appears that Grímsvötn / Grímsfjall are rising fast. But current inflation according to the GPS data is now 80mm. But was around 70mm few days ago. Given this GPS data it is clear that Grímsvötn / Grímsfjall might erupt sooner then estimated by the geological scientists in Iceland. But they where expecting a eruption in Grímsvötn / Grímsfjall later this winter at earliest.
It currently is impossible to know when Grímsvötn / Grímsfjall is going to erupt. But given the GPS data at current time it is going to happen sooner rather then later. It is clear that Grímsvötn / Grímsfjall is worth keeping watch on, as a eruption can happen with little or no warning at all.
The news tonight at Stöð 2 (Channel 2) in Iceland reports that there is a new ash trail visible from the top crater in Eyjafjallajökull. It can be seen because of the new snow layer on top of Eyjafjallajökull that did fall few days ago.
Geologists find this interesting. But they are unclear on why this happens. But they doubt this is due to explosions happening in the crater. The ash is either carried by steam or by wind over the crater rim and falls into the new snow on top of Eyjafjallajökull.
The news can be viewed here (in Icelandic, Windows Media Player required to view this video).
Icelandic Rúv broadcaster reports that a few volcanoes in Iceland are ready to start erupting at any time with little warning. The volcanoes on top of the list are the volcanoes Grímsvötn (Grímsfjall) and Hekla. According to this news they are expecting that a Grímsvötn are going to erupt sometimes in the coming winter. In this news they also say that there are 35 active (dormant) volcanoes that can erupt at any time in Iceland. But some volcanoes are more ready then others to start erupting.
The news can be found here in Icelandic (Windows Media Player required to view the video).
There are many volcanoes in Iceland that don’t enjoy the publicity and the fame like the most active volcanoes in Iceland. That list contains mountains like Hekla, Katla, Eyjafjallajökull, Grímsvötn (Grímsfjall) and so on.
Hamarinn or Lokahryggur (Loki-Fögrufjöll) as it sometimes called is a small volcano under the Vatnajökull glacier icecap. Over the history it has not made many known eruptions. The last eruptions was in the year 1910 according to Global Volcanism Program. But according to Global Volcanism Program there might have been a eruption in the year 2008 and before that in the year 2006. The full list of uncertain eruptions can be found here.
This volcano is inside Bárðarbunga fissure system. But is independent of Bárðarbunga volcano. Hamarinn volcano does not have any caldera according to studies.
Icelandic Met Office has a good map of this area, to my surprise. That map can be found here. This map shows well all the volcanoes that are not listed at Global Volcanism Program website as there own volcanoes, or they might not even be listed at all on there web page.
Over the past weeks there have been deep earthquakes happening under Eyjafjallajökull. The deepest earthquake so far that has happened was on 21 km depth. The latest earthquake that happened was on close to 15 km depth. Currently it is impossible to know if there is new magma pushing up.
If it is, then the amount of magma that is rising up trough Eyjafjallajökull is not great and is unlikely to start a new eruption any time soon. It is however worth noticing that this might change with a short notice. But the eruption in March to May 2010 did show that magma can rise fast up trough Eyjafjallajökull and appears to be followed by earthquake activity.
The volcano named Hamarinn in Vatnajökull glacier is a small and relativity unknown volcano in Iceland. As it has not erupted in recent history. Currently it is so unknown that it isn’t even properly registered at Global Volcanism Program website for this region in Iceland.
Currently the area is producing a lot of earthquakes. But those earthquakes appears to more tectonic in nature at this stage. Currently there is nothing indicating a imminent volcano eruption in the area. But that in it self might change with a short notice, as this area is volcano active. But it is also important to notice that the sequence that leads to a eruptions in this area is relativity unknown due to long dormancy in this area.
It is clear however that is worth keeping watch on this area in the nearest future. As history has shown that in Iceland that volcanoes do come with surprise eruptions with little to no warning at all. Hekla volcano is being the most famous volcano that behaves in such manner.