Category: Volcano

Posted on

Update on the TFZ earthquake swarm at 01:01 UTC

This is a short update on the earthquake swarm in TFZ. This is going to be a long earthquake swarm from the looks of it (currently).

The earthquake swarm in TFZ continues as it has been doing for the past six days now. The strongest earthquakes for the past 24 hours have had the magnitude 3.5, 3.6 and now 3.3 (automatic magnitude). This is a extremely complex earthquake swarm. Over a period of 48 hours there have been around 368 earthquakes. That is a drop in activity, but in the first few hours after the magnitude 5.5 earthquake in TFZ there where recorded over 500 earthquakes.

130406_0015
Earthquake activity in TFZ for the past 48 hours. Copyright of this image belongs to Icelandic Meteorological Office.

130406_0015_trace
The trace plot that shows the earthquake activity for the past 48 hours in TFZ. Copyright of this image belongs to Icelandic Meteorological Office.

This earthquake swarm is complex due to three factors. There is a both slip fault and normal fault taking place there. There also appears to be a volcano in the area. But it not properly understood and is extremely poorly studied. It is unclear at present time if this volcano is connected to this earthquakes swarms at present time. Since so little is known about it. It is also not known if the current earthquake swarm is going to start something in the volcano. The second volcano that is in this area last erupted in the year 1868 following an earthquake swarm in this area. Why that did happen is also not known. But it has a Global Volcanism profile here. The volcano that is closer to Grímsey Island is currently unnamed. There is also almost no studies or documentation on it. But from the little I did find

Please note that the earthquake swarm information is always changing so this information here do get outdated fast. This mostly applies the maps and number of earthquakes.

Scientific data on Tjörnes Fracture Zone

As I did say here above. The Tjörnes Fracture Zone is complex and that is making this earthquake swarm extremely complex as it is taking place.

img94
The rift fault lines in TFZ. This is the simple version. It is from a science study that can be found here. Copyright of this image belongs to Icelandic Meteorological Office/Hjorleifur Sveinbjornsson.

1-s2.0-S0264370706000597-gr2
More complex nature of the fault systems in TFZ. Copyright of this image belongs to Agust Gudmundsson. From study Infrastructure and evolution of ocean-ridge discontinuities in Iceland.

1-s2.0-S0040195107003794-gr1
More complex image showing the fault lines in TFZ. Copyright Ragnar Stefansson, Gunnar B. Gudmundsson, Pall Halldorsson. From the study Tjörnes fracture zone. New and old seismic evidences for the link between the North Iceland rift zone and the Mid-Atlantic ridge.

1-s2.0-S0025322701001724-gr2
The most detailed picture that I was able to find of Tjörnes Fracture Zone and the ocean floor. Copyright of this image belongs to many people. Please see the list of copyright holders in the following link. From the study First observations of high-temperature submarine hydrothermal vents and massive anhydrite deposits off the north coast of Iceland.

It is clearly worth watching this earthquake activity. Since it might have interesting effects on the volcano where this earthquake activity is taking place. Even on the second volcano just north of Þeystareykjabunga volcano.

Posted on

Minor dike intrusion in Bárðarbunga volcano

Today (05.04.2013) a minor earthquake swarm took place in Bárðarbunga volcano. The depth of this earthquakes was around 18 – 26 km. Meaning this is magma, rather then tectonic creating this earthquakes. None of this earthquakes had magnitude above 1.0.

130405_2140
Earthquakes in Bárðarbunga volcano. They are the orange dots. Copyright of this image belongs to Icelandic Meteorological Office.

Dike intrusions happens sometimes in Bárðarbunga volcano without it meaning there is a eruption going to take place soon it. This appears to be one of those cases.

Posted on

Magnitude 3.6 earthquake in Hamarinn volcano

Last night (05.04.2013) at 01:50 UTC a magnitude 3.6 earthquake took place in Hamarinn volcano (no GVP profile yet!). This earthquake had the depth of 2.1 km. This seems to be a dike intrusion taking place in Hamarinn volcano. No clear signs of harmonic tremor have been detected based on tremor data from Icelandic Meteorological Office.

130405_2140
The Hamarinn volcano is where the green star is. But that is the location of the magnitude 3.6 earthquake that took place last night. Copyright of this image belongs to Icelandic Meteorological Office.

skr.svd.05.04.2013.22.12.utc
Harmonic tremor plot do not show any harmonic tremor pulse. The signal on this harmonic tremor plot is the earthquake swarm in TFZ for most parts. Copyright of this image belongs to Icelandic Meteorological Office.

This earthquake activity is due to minor dike intrusion. Rather then something else. It is not clear if this activity is just normal activity for Hamarinn volcano or signal about something else is about take place. But as before. Hamarinn volcano remains mostly quiet for the moment.

Posted on

Deep earthquakes in Askja and Kverkfjöll volcanoes

This is a update for both Askja and Kverkfjöll volcanoes. Since they both had deep earthquakes today. None of this earthquakes where larger then magnitude 1.0. There depth was around 22 to 24 km inside the volcanoes them self.

130331_1700
Earthquakes in Kverkfjöll and Askja volcanoes. There depth was around 22 to 25 km. Copyright of this image belongs to Icelandic Meteorological Office.

GVP Kverkfjöll volcano profile. GVP Askja volcano profile.

It is impossible to know for sure what this means in terms of future activity. But this are both active volcanoes and should be treated as such.

Posted on

Magnitude 4.4 earthquake north of Kolbeinsey Island

Today at 17:32 UTC there was a magnitude 4.4 earthquake north of Kolbeinsey Island. I do not know if this earthquake was tectonic or volcanic in nature. I do know that there where several aftershocks following this earthquake. Since I did register them on my geophone in north Iceland. The geophone web site can be viewed here. More information about the earthquake can be found here, on EMSC web page.

310421.regional.svd.29.03.2013.m4.4
Regional view of the area where the earthquake took place. Copyright of this image belongs to EMSC.

Icelandic Meteorological Office did also detected many of this earthquakes that took place there. But detection from this location is difficult due to distance from the SIL network.

130329_2050
The earthquake swarm location according to Icelandic Meteorological Office. Copyright of this image belongs to Icelandic Meteorological Office.

For now this is just a earthquake swarm and nothing else. Regardless of what happens later. Earthquake activity has been common in this area of the rift zone for several months now. I do not know why that is. The ocean depth in this area is around 3 to 4 km where it is the deepest. So if an eruption takes place there it is not going to be noticed due to the depth of the ocean.

Posted on

Deep earthquakes in Askja volcano

Today (26.03.2013) at 08:09 UTC there where three deep earthquakes in Askja volcano. The most depth of this earthquake swarm was 25.5 km. None of the earthquake had the magnitude above 2.5. The strongest earthquake had the magnitude 2.1 with the depth of 20.4 km

130326_1410
Earthquakes in Askja volcano. Askja is located to the north of Vatnajökull glacier and the lake is round in shape on this map. Marked by the orange dots on it. Copyright of this image belongs to Icelandic Meteorological Office.

This activity is part of an progress that started in Askja volcano back in the year 2010. So far this has not lead to any eruption. But it has created some odd changes. Along one was that Askja lake was ice free last year (winter 2012). The reasons for that are still not known to me.

Blog post updated at 16:32 UTC on 26.03.2013.

Posted on

Uncertainty level declared on Hekla volcano

Uncertainty level has been declared on Hekla volcano due to strange earthquake activity in it for the past week or so. But in total of seven earthquakes where recorded in Hekla volcano at the depth of 11 to 12 km. This is highly unusual for Hekla volcano. People are advised against going up to Hekla volcano while uncertainty level is in force. It is also dangerous to be too close to Hekla volcano. Since if an eruption starts, it is going to start without any warning at all.

I am going to post updates on Hekla volcano as needed if anything happens. It is possible to watch activity live from Hekla volcano on my geophone page here. But I have a geophone located about 16 km away from Hekla volcano. List of web cameras that I know of are online and focused on Hekla volcano can be found here. Update 1: Web camera that is showing Hekla volcano (pictures) can also be found here.

News about this in English

Seismic activity in Mount Hekla (Rúv.is)

News about this in Icelandic

Ekki mikið um jarðskjálfta við Heklu (Rúv.is)
Óvenjuleg jarðskjálftahrina í Heklu (Rúv.is)
Engin bráðahætta á eldgosi (Rúv.is)
Jarðhræringar í Heklu: Óvissustig í gildi (Rúv.is)

Óvissustig vegna Heklu (mbl.is)
Engin sjáanleg merki um eldgos í aðsigi (mbl.is)
Hægt að fylgjast með Heklu (mbl.is)

Óvissustig vegna hugsanlegs goss í Heklu (Vísir.is)
Ferðamenn varaðir við að vera nærri Heklu (Vísir.is)
Fyrirvarinn yrði einn til tveir tímar (Vísir.is)

Ó­vissu­stig vegna ó­venju­legra hræringa í Heklu (DV.is)
„Hekla gaus með litlum fyrirvara síðast“ (DV.is)
Eftirlitsstig vegna Heklu hækkað úr grænu í gult (DV.is)

Blog post updated at 17:26 UTC on 26.03.2013.

Posted on

New earthquake in Hekla volcano

This morning there was an earthquake in Hekla volcano at 08:23 UTC. This earthquake had the magnitude of 1.4 according to the reviewed data from Icelandic Meteorological Office. The depth of this earthquake was 11,2 km. But that is considerable depth for this location. This is most likely not tectonic earthquakes. But it is hard to be sure on that detail as of this moment.

130321_1540
The earthquake in Hekla volcano is marked by an orange dot on this map. Copyright of this image belongs to Icelandic Meteorological Office.

I do not have a clue what Hekla volcano is up to at the moment. But this is highly unusual activity for this volcano. Since normally there are no earthquakes in Hekla volcano until just before an eruption takes place in it. For the moment. The only thing that can be done now is to monitor what is taking place in Hekla volcano.

Posted on

Earthquake activity in Esjufjöll volcano

Earthquake activity has started again in Esjufjöll volcano after some time with no activity. The two earthquakes that where detected by the SIL network only had the magnitude of 1.0 and 1.1. But what is most interesting is there depth. But registered depth is around 0.1 km (around 100 meters). This really shallow depth for earthquakes in this location. While it is unclear what is creating this earthquake activity. The most likely reason is that an minor dike intrusion is taking place in the volcano. Last eruption in Esjufjöll volcano is believed to have taken place in the year 1920. But that has not been properly confirmed yet.

130318_1510
Earthquake activity in Esjufjöll volcano is marked by the red dots in Vatnajökull glacier. Copyright of this image belongs to Icelandic Meteorological Office.

It is impossible to know for sure what is happening in Esjufjöll volcano. Not only is there little known about earlier eruption history of this volcano. It has also been poorly studied in the past. So what to expect if anything happens is not known properly. Based on earlier earthquake activity in this volcano from the year 2011 more earthquakes might happen in next few days to months. But it is impossible to know that for sure at the moment. But it is not an bad idea to monitor this volcano for any more activity in next few weeks.