Category: Earthquakes

Posted on

Interesting earthquake activity in Hamarinn volcano

Over the past few days interesting earthquake activity has been taking place in Hamarinn volcano. The earthquakes have been aligning along two east-west lines. Possibly an fissure in the volcano. I am not sure why this is happening, but I did record one earthquake from Hamarinn volcano today (07-September-2013) and that trace suggests this earthquakes have there origin in magma movements in the Hamarinn volcano. That has not yet been confirmed and this might never be confirmed due to lack of data. Largest earthquake so far had the magnitude of 2.2 at the depth of 4.5 km.

130907_2100
Hamarinn volcano earthquake activity. Copyright of this image belongs to Icelandic Meteorological Office.

Last eruption in Hamarinn volcano was on 11 – 12-July-2011. It was an minor eruption and I did cover it here and here. Small eruptions are common in Icelandic volcanoes just as the are in other volcanoes around the world. Before the minor eruption in the year 2011 there was several months of earthquake activity in Hamarinn volcano. The area that now has this earthquake activity is the same area that had this minor eruption in the year 2011. I do not know if current activity is an early indicator that it is going to happen again. It however cannot be ruled out currently. What can be done is to monitor current levels of activity and just wait and see what happens next.

Posted on

Minor earthquake swarm in Esjufjöll volcano

Today (05-September-2013) an minor earthquake swarm took place in Esjufjöll volcano. Largest earthquake in this swarm had the magnitude of 2.2 and the depth of 4.9 km.

130905_2200
Earthquake swarm in Esjufjöll volcano. Esjufjöll volcano are located in south part of Vatnajökull glacier, just northeast of Öræfajökull volcano. Copyright of this image belongs to Icelandic Meteorological Office.

Earthquakes in this area are because of magma movement it is believed. Now there are more SIL stations in the area, so more earthquakes are being recorded. Few years ago the lowest magnitude that Icelandic Meteorological Office was able to detect in Esjufjöll volcano was magnitude 1.5 and above.

Posted on

Earthquake activity in several volcanoes

Today (04-September-2013) had some minor earthquake activity in several volcanoes in Vatnajökull glacier. All of this earthquakes were small and less than magnitude 3.0 in size.

Kverkfjöll volcano

The deepest earthquake activity was in Kverkfjöll, with earthquakes at 31 km depth and 24 km depth. This deep earthquake activity is possible connected to magma movements since tectonic earthquakes are unlikely to take place this deep in the crust.

Grímsfjall volcano

One earthquake was recorded in Grímsfjall volcano, it was minor and shallow. This might even just be a glacier quake, rather than normal earthquake.

Öræfajökull volcano

Öræfajökull volcano did see two earthquake today, at the depth of 4 to 5 km. Both were small and tectonic in nature from the looks of it. Earthquakes are not common in Öræfajökull volcano so I am not sure why this increase has now taken place. It is worth noticing that sil network is now more sensitive in this area than before since new stations have been added in this area. This means that smaller earthquakes are now being detected than before.

Esjufjöll volcano

Esjufjöll volcano had two earthquake, the third earthquake might be a ice-quake. I am not sure if it was an real earthquake or not. Esjufjöll volcano normally do not have any earthquake activity, but few years ago an earthquake activity started with earthquakes that had magnitude of 2.5 to 3.0 so there is something going on in this volcano. What that might be I am not sure of yet.

130904_2225
Earthquake activity in Kverkfjöll, Öræfajökull, Esjufjöll, Grímsfjall volcanoes. All small earthquakes. Copyright of this image belongs to Icelandic Meteorological Office.

I do not expect anything major to take place in Vatnajökull volcano. Since the current quiet period in Iceland just seems to be ongoing as is.

Posted on

Minor earthquake in Hekla volcano

Today (04-September-2013) a minor earthquake took place in Hekla volcano. The magnitude of this earthquake was just 0.4 and the depth was 0.1 km, so this earthquake was not connected to magma movements of any type.

130904_2025
The earthquake in Hekla volcano. Copyright of this image belongs to Icelandic Meteorological Office.

Based on how shallow this earthquake was, it is unlikely that it means anything in terms of possible eruption in the volcano. At the moment there are same chances for Hekla volcano eruption as any other day of the week, that has not changed at all.

Posted on

Minor earthquake swarm in Torfajökull volcano

Today (03-September-2013) a minor earthquake swarm took place in Torfajökull volcano. The largest earthquake had the magnitude of 1.1, no other larger earthquakes took place in Torfajökull volcano.

130903_1955
Earthquakes in Torfajökull volcano. Copyright of this image belongs to Icelandic Meteorological Office.

Smaller earthquake swarms are common in Torfajökull volcano. They do not mean that eruption is about to take place, however magma is shallow in Torfajökull volcano and it has not erupted since 15th century at least (I think, there is no use in GVP website at the moment).

Donations: It would be nice if people donated so that I can buy food this month. In other case I am going to have to eat really little this month and I am not happy about such things taking place.

Posted on

Minor dike intrusion into Bárðarbunga – Hamarinn volcanoes

It seems that yesterday (02-September-2013) a minor dike intrusion took place in Bárðarbunga – Hamarinn volcanoes. This created an minor harmonic tremor yesterday on nearby sil stations. There were earthquakes following this events, the strongest one had the magnitude of 2.8 at the depth of 14 km. A second earthquake with the magnitude of 2.1 took place few moments later, it had the depth of 15.5 km. Only one smaller earthquake have seen taken place in this area of Bárðarbunga – Hamarinn volcanoes.

130903_1920
The earthquake activity in Báðarbunga – Hamarinn volcano area. Copyright of this image belongs to Icelandic Meteorological Office.

It is important to notice that dike intrusions are common in this area, often happen many times a year. How many takes place can vary between years. That dike intrusion took place does not mean an eruption is going to take place. It just means that magma moved, what that means for the future is unknown at present time.

Donations: It would be nice if people donated so that I can buy food this month. In other case I am going to have to eat really little this month and I am not happy about such things taking place.

Blog post updated at 21:43 UTC on 3-September-2013.

Posted on

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.

130813_1315
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.

Posted on

Earthquake swarm on the Reykjanes Ridge

A minor earthquake swarm took place on the Reykjanes Ridge during the night, it started at 04:17 UTC and ended at 08:13 UTC, there was some break in activity for few hours with each episode lasting for around 10 minutes. Earthquake swarms are common in this area of the Reykjanes Ridge. The largest earthquake in this swarm had the magnitude of 2.9, other earthquakes were smaller in magnitude.

130811_1215
The earthquake swarm on the Reykjanes Ridge, the earthquakes scattered around wrong locations by the automatic SIL system. Copyright of this image belongs to Icelandic Meteorological Office.

This earthquake swarm did appear clearly on my geophone network in Iceland. It can be viewed here. I do not know if this means more activity is coming on the Reykjanes Ridge, it is all just wait and see what happens in this case.

Posted on

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.

130806_1545
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.

Posted on

Earthquake swarm in Tjörnes Fracture Zone

Yesterday (31-July-2013) a earthquake swarm started in TFZ, the south end of it, not far from a village named Kópasker. This earthquake swarm was small most of yesterday, but after midnight this earthquake swarm started to pick up in activity and magnitude of earthquakes. Around 07:09 UTC this morning (1-August-2013) a magnitude 3.7 earthquake took place, this earthquake was felt in Kópasker along with few magnitude 3.0 earthquake that took place after it. The epicenter of this earthquake swarm is out in the ocean, so no population is any major danger if this earthquake swarm continues as is.

130801_1450
The earthquake swarm in TFZ today. Copyright of this image belongs to Icelandic Meteorological Office.

This earthquake swarm is currently ongoing and there are no signs that is going to end soon, current activity is not continuous, it drops regularly and then it resumes again. It is impossible to know for sure how long this earthquake swarm is going to continue. The largest earthquakes appear clearly on my geophone and can be seen here.

Blog post updated at 18:11 UTC on 01-August-2013.