Category: Volcano

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Interesting harmonic signals appearing around Vatnajökull glacier

In the past few hours an interesting harmonic signals have been taking place on two sil stations (so far) around Vatnajökull glacier. I do not know what is creating this harmonic tremor spikes on them, it might be water on the move or starting to move from Skaftár cauldron in Vatnajökull glacier or it might be something different that I do not know about at present time. Currently the source of this harmonic tremor is unknown and it might never been known in the worst case. I do hope to figure out in next few hours what is creating this harmonic tremor spikes on this two sil stations.

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The harmonic tremor signal at Skrokkalda sil station. The harmonic tremor signal can be found at the end of the tremor plot. Copyright of this image belongs to Icelandic Meteorological Office.

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The harmonic tremor signal at Jökulsel sil station. It is at the end of the tremor plot. Copyright of this image belongs to Icelandic Meteorological Office.

As I say above, the source of this tremor signal is not known. It might be bad weather in the area, traffic (unlikely due to bad weather in this part of Iceland at the moment) or something that is not known at the moment. What I can rule out at the moment is this harmonic tremor signal does not appear to come from magma movement, the frequency of the harmonic tremor is too high for that at the moment and does not show little to no energy at 0.5 to 1 Hz band. This suggest the source is something else then magma, this however does not rule out magma. Since magma is known to due many strange things under pressure and high frequency harmonic tremors are not unknown, but they are unlikely to take place rather than being a common feature in volcano activity.

For the moment the best thing that can be done is to monitor the signal and see if there are any changes and on the nearby sil stations. For the moment I do not expect any major change in this area, risk of glacier flood is still in place for this part of Vatnajökull glacier. If this harmonic tremor signal connects to that is not known at the moment.

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Possible glacier flood from Skaftár cauldron

It is possible that glacier flood from Skaftákötlum cauldron has started some hours ago. According to Rúv, Icelandic Meteorological Office is now monitoring for signs that glacier flood has started. Changes in conductivity in glacier rives from Vatnajökull glacier (South-West) and the rivers that normally flood from Skaftárkötlum cauldron. It has not been confirmed that glacier flood has started yet.

At the moment it has not been confirmed that glacier flood has started, but it might start soon. I am going to post more information once I have them or when they are published.

Icelandic News about this

Fylgjast náið með Skaftárhlaupi (Rúv.is)

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Glacier flood from Hofsjökull volcano continues

Yesterday (21-August-2013) saw the start of small glacier flood from Hofsjökull volcano, this glacier flood has continued today and west Jökulsá in Skagarfirði continues to smell of sulfur and is dark color. Conductivity remains high in the glacier river following this glacier flood. It is not known currently for sure what areas of Hofsjökull volcano this comes from or what cauldrons are emptying of hydrothermal water build up.

Announcement (seen on Facebook) from Almannavarnir (Iceland Civil Protection) and Icelandic Meteorological Office on the strength of sulfur following this glacier flood is so high that it is dangerous to be close the source of the glacier flood (closest to Hofsjökull volcano). Strength of sulfur in the area is high enough to damage people lungs, travellers in the area advised to stay away from the source of the glacier river Jökulsá until this glacier flood is over, that might take few days at most. No earthquake activity has been observed in Hofsjökull volcano following this glacier flood. The volcano has been completely quiet during this glacier flood and at current time do not expect it to show any activity. Currently there is little known about Hofsjökull volcano and the activity in it, since it has never erupted during modern era (past 12.000 years).

Icelandic news about this glacier flood

Kanna hvað er á seyði í Vestari Jökulsá (Rúv.is, Icelandic)
Lítið jökulhlaup í Hofsjökli (Rúv.is)
Hlaup í Vestari Jökulsá (mbl.is, pictures)

Blog post updated at 16:56 UTC on 22-August-2013.

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Possible glacier flood from Hofsjökull volcano

It has been reported today that possible glacier flood has taken place in Hofsjökull volcano. Reports did come to Icelandic Meteorological Office that a glacier river named Jökulsá Vestri in Skagarfirði (Wikipedia). It is not known what is causing this change in the glacier river, it might be anything from a mud slide to change in the glacier itself. Amount of water in the glacier river has not changed according to IMO monitoring of the river.

Smell of sulfur has been reported with this change in the glacier river. That means the water has been in contact with hydrothermal areas that are under Hofsjökull glacier (volcano). No earthquake activity or change of any type has taken place following this change in Jökulsá Vestri in Skagarfirði.

If anything more happens. I am going to update this blog post or post an new one if I need to.

Icelandic News on this event

Jökulsá Vestari óvenjuleg á litin (Rúv.is)
Brennisteinslykt við Goðdali (mbl.is)

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Steam explosion in Kverkfjöll volcano on 16-August-2013

During the night of 16-August-2013 several steam explosions took place in Kverkfjöll volcano. This steam explosions were a result of glacier flood that took place few hours earlier, since under the glacier lake in question are hydrothermal areas (hot spring). This hot springs are so hot they do not emit hot water, they emit steam and that means they are warmer than 150 Centigrade. When under pressure this water has higher boiling point. When a glacier flood happens there is a change in pressure, the boiling point of the hot water moves down, this super heats the water and a pressure explosion takes place.

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Effects of steam explosion in Kverkfjöll volcano on 16-August-2013. Copyright of this image belongs to Almannavarnir (Civil protection in Iceland). Picture is from Facebook.

I do not know if there has been any change in hydrothermal activity in Kverkfjöll volcano over the past few years. This volcano is remote and it is not easy to go there, even during the summer time. It has been advised for tourist to be careful around Kverkfjöll volcano due to this changes that are taking place there now. Hot springs and other hydrothermal features are always dangerous to get close to.

More information on Hydrothermal explosions and superheated water

Hydrothermal explosion (Wikipedia)
Superheating (Wikipedia)

Blog post updated at 15:04 UTC on 17-August-2013.
Blog post updated at 15:08 UTC on 17-August-2013.

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Minor glacier flood from Kverkfjöll volcano [Updated]

In a announcement from Icelandic Meteorological Office, an minor glacier flood has now taking place from Kverkfjöll volcano, it appears to have started yesterday (15-August-2013). This is one of the minor glacier lakes in Kverkfjöll volcano. This glacier flood in minor and the water levels are not expected to reach more than normal summer level in the glacier river the flood is going into. The glacier river is called Volga and is a glacier river from Kverkfjöll volcano glacier area.

Currently Icelandic Meteorological Office is taking a trip over Kverkfjöll volcano to see the local changes and what is exactly is going on. Current status of the glacier flood is not well known, but latest report suggested that some subsiding was taking place, if that is because the glacier flood is over or something else is taking place I am not sure about at present time.

Update 1: Icelandic Civil Protection has confirmed that steam explosion took place in Kverkfjöll volcano following the glacier flood (due to sudden pressure release) that took place during the night and in the morning. News about that can be found here in Icelandic.

Web cameras of Kverkfjöll volcano

It is possible to view web cameras of Kverkfjöll volcano here. Weather information can be found here.

Icelandic news about this glacier flood

Óvenjulegur vöxtur í Volgu (mbl.is)
Hægt hefur á vexti hlaupsins (mbl.is)

Blog post updated at 20:47 UTC on 16-August-2013.
Blog post updated at 21:29 UTC on 16-August-2013.

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New earthquake swarm on Reykjanes Ridge

During the night at 04:40 UTC a earthquake swarm started on the Reykjanes Ridge. There are no signs of this earthquake swarm being connected to any volcano activity, this just normal earthquake activity for this area. The largest earthquake in this swarm had the magnitude of 3.0, other earthquakes had less magnitude.

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The earthquake activity on the Reykjanes Ridge today. Copyright of this image belongs to Icelandic Meteorological Office.

As with the earthquake swarm on 11-August-2013, this earthquake swarm happens short periods of activity with quiet between them. I do expect this activity to continue for the next hours to days, based on past history for this area. If that is going to happen I do not know yet. Largest earthquakes that can take place in this area can reach the magnitude of 5.5, but no larger than that, since the crust does not support any greater magnitude.

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Where has all the activity gone?

It has been quiet in Iceland this summer, often with only 100 earthquakes during the week (7 days) taking place. This is normal for Iceland, since activity takes happens in jumps, with long quiet period between them. That quiet period can be from few days and up to thousands of years. This is normal for every rift and subduction zone on planet Earth, activity happens in short periods and during that time a lot of things can be going on during that period. Between it nothing is taking place, this applies to Iceland as any other place on Earth. Currently nothing is happening in Iceland and tension is building up while it is quiet, at some random point at some random day this tension is going to break and we are going to have either a earthquake swarm, eruption or both taking place.

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All quiet in Iceland. There is currently some minor summer earthquake activity taking place in Katla volcano. Copyright of this image belongs to Icelandic Meteorological Office.

For more information on Icelandic geology, I recommend this paper (pdf) by Páll Einarsson. It is from the year 2008, but is a good read on the tectonic settings in Iceland. It might be a surprice to many, but in Iceland there are actually 5 rift zones, they are called Western Volcanic Zone (WVZ), Central Icelandic Volcanic Zone (CIVZ), Eastern Volcanic Zone (EVZ), Northern Volcanic Zone (NVZ) and South Iceland Volcanic Zone (SIVZ). Then there is Reykjanes Peninsula Rift (RPR). This zones are not all active at the same time and there dormant time is different, some areas are just dormant for few years to decades, while others are dormant for thousands of years.

For the moment it is quiet, so I have little to write about. Since this blog mostly deals with current activity that is taking place in Iceland.

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Melting of glaciers in Iceland might mean more volcano activity

In the evening news on Rúv tonight (23-July-2013) a interesting report about possible future volcano activity was being reported. A unpublished paper (according to Rúv News) reports that with more glacier melt in Iceland, more eruptions should be expected to take place. This is mostly true about areas like Vatnajökull glacier, as it holds several volcanoes that are under heavy pressure from the glacier ice. This applies mostly to volcanoes like Grímsfjall volcano, Bárðarbunga volcano and Kverkfjöll volcano, but those three volcano are the largest ones in Vatnajökull glacier.

This might also apply to areas like Mýrdalsjökull glacier. If this study is true, there might be more eruptions in Iceland in next few decades as the glacier melts away. This like so many other things, is however something that is just wait and see seranio.

At the moment, everything is quiet in Iceland when it comes to activity in volcanoes and on fault zones in Iceland.

Rúv News about this

Auknar líkur á eldvirkni með bráðnun jökla (Rúv.is, Icelandic, video)

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Minor earthquake swarm in Katla volcano

During the night (22-July-2013) a minor earthquake swarm took place in Katla volcano. Most of the earthquakes where shallow, with the depth of 1 km, one earthquake had the depth of 12 km. This earthquake swarm took place in the central area of the caldera. I am not sure what did create this earthquake swarm, it might have been a dike intrusion, or it simply might just be a pressure changes in hydro-thermal areas in this location.

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Minor earthquake swarm in Katla volcano. Copyright of this image belongs to Icelandic Meteorological Office.

This earthquake swarm is probably just part of normal summer activity in Katla volcano, at least there is nothing that suggests otherwise at present time. It is possible to watch the activity in Katla volcano here from my geophone at Skeiðflöt farm, just outside Katla volcano.