Category: Earthquakes

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Information about the Mw4.9 earthquake in north Italy

Today (25.01.2012) at 08:06 UTC (09:06 local time) an earthquake with the size of Mw4.9 did happen in north Italy according to EMSC. This earthquake was not far from the ML4.3 earthquake that did happen in nearby area yesterday (24.01.2012). According to reports this earthquake was clearly felt and some light damage has happened following this earthquake. I am not sure on aftershock activity in this area. But so far the largest aftershock has been with the size ML3.5, it was also felt in nearby towns.


The regional location of the Mw4.9 earthquake according to EMSC. Copyright of this picture belongs to EMSC.


Local view of the area where the Mw4.9 earthquake took place. Copyright of this picture belongs to EMSC.

More aftershocks are possible in this area. The trigger for this earthquake is most likely the earthquake that did happen yesterday and had the size of ML4.3. How that works is unclear. But the area in question was already at breaking point, so it needed little to break and make the earthquake happen. EMSC has put up an special web site with more information about this earthquake. That web site can be viewed here.

If any more large earthquakes happen. I am going to write about it soon as I can.

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A ML4.2 earthquake in north Italy

According to EMSC there has been a ML4.2 earthquake in north Italy at 23:54 UTC on 24.01.2012. This earthquake appears to be located close to populated areas. I do not yet know if there has been any damage due to this earthquake. But if houses in the area are poorly built, there might be some light damage. It is hard to know for sure if this is an pre-earthquake or just one earthquake. There have already been some minor aftershocks already. But so far none of them have been larger then ML2.1.


The regional area where the earthquake took place. Copyright of this picture belongs to EMSC.


Local area where the earthquake took place. Copyright of this picture belongs to EMSC.

I am going to update this blog post if anything more happens in Italy where this earthquake took place.

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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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Earthquake(s) in Hekla volcano

At 17:53 UTC there where two (or one) earthquake(s) in Hekla volcano. They where in the main volcano it self. The size of this earthquakes where ML06 and ML0.7, the depth was 2.5 km and 0.7 km. I am unsure what this means. But there is an slight possibly that an eruption might be under way. But at the moment no eruption has started so far. So only thing that can be done is to wait and see what happens next.


The earthquake in Hekla volcano at 17:53 UTC. Copyright of this picture belongs to Iceland Meteorological Office.

All that can be done for the moment is wait and see what happens. As so far this is the only earthquake in Hekla volcano. But that can change without warning at any time. I am going to monitor this as best I can this evening. But I am going to be away part of the evening and not close to any internet connection.

Update 1: An second earthquake did happen in Hekla volcano system during this morning. Its size was ML0.8 with the depth of 2.2 km. Other earthquakes that have happened also have been corrected. But the size of those earthquakes where ML1.0 at 0.1 km depth and ML0.7 at 8.3 km depth. Two of this earthquakes (ML0.8 and ML0.7) where not in Hekla volcano it self. But inside Hekla volcano system at good distance from the mountain it self.

Hekla volcano system earthquake during the past 48 hours. Small earthquakes have been taking place in the south end of Hekla volcano system (north of Hvolsvöllur village) for several months now. What this means I have no idea. Copyright of this picture belongs to Iceland Meteorological Office.

Blog post updated at 18:41 UTC on 22.01.2012.

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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 earthquakes in Hekla volcano system

During the past 24 to 48 hours there has been some unusual and interesting earthquake activity in south part of Hekla volcano system. I am unsure on what this means, as normally Hekla volcano does not have any earthquakes before an eruption. However, that is not the only type Hekla volcano can and has erupted over the centuries. One of the aspect of Hekla volcano eruptions is that it can and has erupted in fissure eruptions outside the main mountain. This type of eruptions can last from few week and up to almost a year. Based on the limited historical records of such events. This type of events are always basaltic lava events that do not make a lot of volcano ash when they start.


The earthquakes in Hekla volcano during the last 48 hours. Copyright of this picture belongs to Iceland Meteorological Office.

There are clues that Hekla volcano might be about to have an fissure eruption some time in the future. But when and where is impossible to know for sure at current time. How that is going to manifest it self when the time comes is also impossible to know for sure. At current time there is however no eruption starting in Hekla volcano. When it might start is an good guess, with no answer to it.

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New magma injection into El Hierro volcano

Based on the earthquake activity in El Hierro volcano it seems that new magma injection has taken place, or is taking place at current time in El Hierro volcano.

This new magma injection into El Hierro volcano has already been followed by stronger harmonic tremors and more activity on the surface. As should have been expected when this happens. It is impossible to know at the moment how large and how long this new magma injection is going to last. But while it is ongoing, more eruption activity should be expected from El Hierro volcano. So far nothing suggests that new vents are about to open up in El Hierro volcano at the moment.

Other then this renewed activity. Nothing else has been happening in El Hierro volcano. There have been some news reports (in Spanish, use Google Translate to read) about new thermal anomalies in El Hierro volcano. This might just be hydro-thermal activity following dike intrusions at shallow depth.

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New earthquake activity in Upptyppingar tuff mountains

During last week and on 5. January 2012 there where few earthquakes in the Upptyppingar tuff mountains. This mountains are not volcano by definition (yet anyway). But since the year 2007 there has been magma intrusion into that area. This magma intrusion however stopped and has been stopped for several years now. But that might be about to change. As on 5 January 2012 there where few small earthquakes with the depth of 12 km. Last eruption that took place in the Upptyppingar tuff mountain area where about 12.000 years ago, around the end of the last ice age. Considerable deformation has taken place in the crust in Upptyppingar tuff mountain since magma started to build up there. Current earthquake activity in Upptyppingar tuff mountain is not high at the moment however. But it has remained rather constant for the past 7 to 10 weeks at least. But due to lack of SIL stations in the area, it is hard to know how many earthquakes have exactly been taking place there at the moment.

Upptyppingar tuff mountains are part of Kverkfjöll volcano system. This new magma into Upptyppingar tuff mountains suggests that Kverkfjöll volcano might be about to enter an new time of activity. But they have been dormant since the year 1968 at least. But Kverkfjöll volcano have also been seeing some earthquake activity on its own.

It is most likely is the case that we are going to see eruption taking place in Upptyppingar tuff mountain one day. But the wait for it might be long however.

A research papers into the activity in Upptyppingar tuff mountain.

Resarch #1 (pdf file)
Research #2 (pdf file)