Category: Swarm

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Earthquake with the magnitude of ML4.7 in Hawaii Island

Last night at 02:36 UTC (23.01.2012) there was an earthquake with the magnitude of ML4.7 in Hawaii Island. This earthquake was felt according to what I have been reading about on the forum. This earthquake activity is most likely due to changes in tectonic stresses in the area. Rather then anything volcanic.


The location of the earthquake. Copyright of this picture belongs to EMSC-CSEM.


Location of the earthquake from USGS. Copyright of this picture belongs to USGS.

The largest aftershock following this earthquake did get the size ML3.1 Earthquake activity is currently ongoing. But I do not know to what extent exactly. Sharp aftershocks should be expected in this area in the next few hours to days.

M 5.0 – ISLAND OF HAWAII, HAWAII – 2012-01-23 02:36 UTC (EMSC)
Magnitude 4.7 – ISLAND OF HAWAII, HAWAII (USGS)

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Small earthquake swarm in Hengill volcano

Yesterday (17.01.2012) an small earthquake swarm started in Hengill volcano. This earthquake is in the area where Orkuveita Reykjavíkur (OR) has been pumping down cold water from the hydro-thermal power plant that they have in the area. So far the largest earthquake in this minor earthquake swarm is just ML2.0 in size according to automatic size estimation. The depth of this earthquake swarm is around 5 km.


The earthquake activity in Hengill volcano today and yesterday (17.01.2012 and 18.01.2012). Copyright of this picture belongs to Iceland Meteorological Office.

The earthquake activity in this area repeats it self regularly due to water being pumped down into the ground. This has increased the risk of large (Mb5.0 or larger) earthquake in this area. But it is impossible to be sure if such events take place. As this is most likely just going to speed up an process that is already in place by nature forces in Hengill volcano (earthquakes, nothing else). So for the moment, the only thing that can be done is to wait and see what happens next.

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Earthquake swarm north of Jan Mayen Island

This blog officially also covers Jan Mayen Island north of Iceland. But since the Jan Mayen Island is uninhabited, activity there is not on the top priority list and I do not mention the Jan Mayen area as such because of this.

Yesterday (15.01.2012) there where two earthquakes detected by EMSC north of Jan Mayen Island. This earthquakes happened in the rift zone that is in this area. The largest earthquake had the size Mb4.9 with the default depth of 10 km. The smaller earthquake had the size Mb4.2 with the default depth of 10 km.

This area has the depth of around 2 km where it is shallowest (mountain peaks) so it is impossible to what is going on. But this is most likely tectonic earthquakes rather then volcanic earthquakes that are taking place in this area. But due the distance from populated areas and any seismometer networks only the largest earthquakes are detected when they happen. Norway National Seismic Network can be found here, they have some better resolution of earthquakes in the Jan Mayen Island then EMSC.

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Earthquakes about 88 km south of Höfn í Hornarfirði

Earlier tonight an earthquake swarm started around 88 km south of a town of Höfn í Hornarfirði. This area last had an earthquake or earthquake swarm in Week 22 (no map exist of it, but the earthquakes are in the weekly overview list) in the year 2007. Then the largest earthquake was around ML3.0 in size.

So far the largest earthquake has been around ML2.3 in size, with the depth of 9.4 km. But the earthquakes that are detected around ML2.0 in size. But given the distance from the SIL network. This size is the lowest size that can be detected from what I can tell. This is because of the distance from the closest SIL station and how few SIL stations are in this area that are able to detect earthquakes this far out in the ocean. Earthquakes like this regularly happen all around Iceland. But most are not detected due to lack of SIL stations in the area. For that reason it is impossible to know for sure how many earthquakes actually have taken place there, as the SIL network is only recording the largest ones in this area.


The area where this earthquake swarm is taking place is on the edge of Iceland volcanic shelf. This is often refereed to as intra-plate earthquakes. Copyright of this picture belongs to Iceland Meteorological Office.

This area is not volcanic last I knew. As it has no-known volcanoes today and most likely never has had any active volcanoes. In this area the Iceland plate is pushing down the oceanic crust that is on top of. This progress often creates earthquakes as we are now seeing. I have not yet found any research paper, as I am unsure what terms to use to look for the research.

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Minor magma dike intrusion into Upptyppingar tuff mountain

Yesterday (12.01.2012) there was an minor earthquake swarm in Upptyppingar tuff mountain. But they are inside Kverkfjöll volcano fissure swarm that extends several km away from the main volcano. The largest earthquake in this earthquake swarm was around ML2.0 in size, with the depth of 14.4 km. But this was also the deepest earthquake in this earthquake swarm. But most of the earthquakes had the depth of 14.4 km and up to 7.8 km. So I am sure that this was magma, rather then tectonic movements that did create this small earthquake swarm.


The earthquake activity in Upptyppingar tuff mountains. Copyright of this picture belongs to Icelandic Meteorological Office.

This might mean that there is more activity on the way in Upptyppingar tuff mountain. As this suggests that new magma has started to flow into the magma sill that has formed under the Upptyppingar tuff mountains. It is hard to know or if there is going to be an eruption there. But I find it most likely going to be the case. But it might well be good 10 to 20 years into the future until an eruption happens in that spot. But activity started in this area in the year 2007, so there already have been good 5 years since activity started in Upptyppingar tuff mountain. For the moment however, it is all wait and see and earthquakes.

Special donation help wanted!

I want to do something for my mom and dad. How are not the most technical people in the world. The fact is that where they live there is no mobile signal inside the house, but it is good out side the house. This can be fixed with an GSM repeater. But that costs money. Around 47.000 ISK, 2.189 DKK, 244 GBP, 294€, $372. I am going to get permission from the mobile companies and the authorities in Iceland to setup this minor repeater in the licensed spectrum (900Mhz). I want to do this. But I currently do not have the money to do this at present time. That is why I am asking for donation so I can do this. But I want to buy them the smallest GSM repeater that is possible to buy in Iceland, just so that they can get GSM signal inside the house.

Thanks for the support. 🙂

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Renewed eruption activity in El Hierro volcano

Since yesterday there has been an renewed eruption activity in El Hierro volcano. Harmonic tremor has not seen big increase however. This suggest that this new eruption so far is small and mot procuring a lot of lava to the surface. Some floating pyroclastic has been spotted on web cameras and by local people when they come up to the surface. This eruption activity appears be intermittent at the moment. Going on and off every few hours to days.


The harmonic tremor from the eruption in El Hierro volcano. Harmonic tremor remains low however, so there is not a lot of energy in this eruption at the moment. Spikes in the tremor chart are most likely explosions taking place in the eruption area. Copyright of this picture belongs to IGN (Instituto Geográfico Nacional).

The eruption appears to have started again following an new dike intrusion from great depth into El Hierro volcano. This was followed by few earthquakes. All of them where small. If more new magma flows into El Hierro volcano this new eruption episode is going to increase in strength and in power. But it is hard to be sure if that is going to happen or not.


Eruption area in El Hierro volcano. This new eruption seems to be closer to the coast line then before. Copyright of this picture belongs to INVOLCAN. Picture is via Eruption blog (Erik Klemetti)

It is impossible to know what happens next in El Hierro volcano. So watching is important thing to do.

Other blogs about this new eruption.

Renewed Activity at El Hierro in the Canary Islands (Wired Science)

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Eruption starts again then stops again in El Hierro volcano

Few weeks ago the eruption in El Hierro volcano stopped for few hours. Before it did restart at lower levels for few days. Then it stopped again. This type of behavior is not so unexpected as it seems that El Hierro volcano did get some minor magma injection in past few days and around the time the eruption did restart. But this injection of new magma was followed by minor earthquake swarm in El Hierro volcano, with one of the earthquake having the depth of 34 km (automatic depth estimate I think). But this new injections of magma seems to be small compared to the amount of magma that has already been injected into and erupted already in El Hierro volcano.


Harmonic tremor yesterday (03-01-2012) in El Hierro volcano. Copyright of this picture belongs to IGN (Instituto Geográfico Nacional).


Harmonic tremor today (04-01-2012) in El Hierro volcano. Copyright of this picture belongs to IGN (Instituto Geográfico Nacional).

Current level of harmonic tremor in El Hierro volcano suggests an small eruption in the area. But there is now an highly active hydro-thermal area where the eruption started and has been taking place for the past three months. But it is going to take several weeks and up to years for this area to cool down. Then there is also the chance of hydro-thermal activity in the area if there is an dike intrusion into the rock of the El Hierro volcano that has not erupted. If that is the case as might well be. It is going to decades and up to hundreds of years to cool down.

For the moment however the main eruption event in El Hierro volcano is over and it is going to remain like that until new magma is injected into volcano. But that might not happen for hundreds to thousands of years if the current sequence of events that led to current eruption is over. But only time is going to tell us what happens next is El Hierro volcano. As volcanoes are unpredictable in there nature.

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A ML3.4 earthquake 25 east of Grímsey Island (automatic size)

When things gets busy in Iceland, they mean it. At least that is the case now. This also the reason why I do not trust the quiet times in Iceland.

A earthquake with the size of ML3.4 took place 25 km east of Grímsey Island in the TFZ at 21:46 UTC. But that is an non-volcanic zone that bridges the eastern volcanic zone with the North-Atlantic rift zone. This earthquake had an earthquake with the size of ML2.9 taking place before the larger one. That was an pre-earthquake most likely. But it seems that an earthquake swarm is also starting in TFZ as it has done close to Krísuvík volcano on the Reykjanes Ridge. I do not know if this earthquake was felt or not.

I am going to update this blog post if I need to.

Update 1: The location of this earthquake. So far there have not been any aftershocks following the ML3.4 earthquake. Its depth was at 11.5 km. This earthquake does not appear clearly on my geophones due to the distance involved (over 200 km).


The location of the ML3.4 earthquake on TFZ. Copyright of this picture belongs to Iceland Met Office.

Blog post updated at 22:22 UTC.

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A ML3.6 earthquake in Krísuvík volcano (automatic size)

At 21:12 UTC on 3. January 2012 an earthquake with the automatic size of ML3.6 did happen in Krísuvík volcano. I do not yet know if this earthquake was felt in the nearby area. But I assuming that it has done so.

This earthquake did appear clearly on my geophones. Both in north and south Iceland. They can be viewed here. I am going to update this blog post as I know more. But this seems to be an start of earthquake swarm in Krísuvík volcano.

Update 1: It has been confirmed that this earthquake was felt in Reykjavík and nearby area. The automatic depth of this earthquake was 14.2 km according to Iceland Met Office.

Update 2: Earthquake swarm has started in Krísuvík volcano. The largest earthquake in this earthquake swarm after the main earthquake is ML1.1 in size. Larger earthquakes however might happen at any time in this earthquake swarm. But that is at least the experience so far.

Update 3: Here are the traces of the earthquake. Sorry. But for the moment there are no high resolution pictures available as my main earthquake computer is offline until I move back to Denmark. See this blog post here for more details on that.


The location of the ML3.6 to ML3.7 earthquake in Krísuvík volcano. Copyright of this picture belongs to Iceland Met Office.


The ML3.6 earthquake as it did appear on Eyrarbakki geophone. This picture is released under Creative Commons Licence. Please see the CC Licence web page for more detail.


The ML3.6 earthquake as it did appear on the Heklubyggð geophone. This picture is released under Creative Commons Licence. Please see the CC Licence web page for more detail.


The ML3.6 earthquake as it did appear on the Hvammstangi geophone. This picture is released under Creative Commons Licence. Please see the CC Licence web page for more detail.

Blog post updated at 21:38 UTC.
Blog post updated at 21:45 UTC.
Blog post updated at 22:15 UTC.

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Hydrothermal activity in El Hierro volcano

For the moment the eruption in El Hierro volcano has ended. The current harmonic tremor that is being detected might well be from hydrothermal activity that is currently in the area that erupted. But even if the eruption has ended, the area that erupted is going to be warm for many weeks to come. This is going to create hot springs below the sea level, among other ocean phenomena connected to this type of hydrothermal activity.


Harmonic tremor levels remain close to background levels at El Hierro volcano. Taken today at 16:05 UTC. Copyright of this picture belongs to IGN (Instituto Geográfico Nacional).

As for future activity in El Hierro volcano. It is important to remember that eruption activity might start again on a new fissure. But that would be pre-seeded by earthquake activity. After the eruption activity stopped there has been some earthquake activity. But it is not at that level I would expect before a new eruption where about to start in El Hierro volcano. For the moment however things remain quiet in El Hierro volcano. A relieve to the local people in the area I would think.

Other

I want to remind people of the volcano and earthquake forum. It allows for more discussions on volcanoes, earthquakes and other stuff that might not belong to this blog.