This is a short update on El Hierro volcano. I am sorry for just short updates at the moment. But the current events in El Hierro volcano make it hard to know for sure what is going on. So the current status is always changing from one hour to the next. I only write about activity in El Hierro volcano once it has quiet a bit down and I got the most recent information on what has taken place.
Yesterday (29.03.2013) has been the most active day in the El Hierro volcano so far. The largest earthquake today was an magnitude 4.7 earthquake with the depth of 20 km. It was felt in El Hierro Island well and did create minor landslides and rock fall in areas. Many magnitude 3.0 to 4.3 earthquakes did follow this earthquake. But this earthquake is the largest so far. I do not know yet if it signals any change in El Hierro volcano activity. Only time is going to tell us that. If that is going to take place in next few days to weeks I do not know yet. But I am sure it is going show it self soon. Earlier today was also marked by many magnitude 3.0 to magnitude 4.6 earthquakes. Around the same place as the magnitude 4.7 earthquake. The magnitude 4.7 earthquake was felt in La Palma and Tenerife, a good distance from El Hierro volcano.
Pattern of earthquakes in El Hierro volcano is interesting as now shows it self. But I do not know what it means so far. All I do know is that magma is being injected at depth into El Hierro volcano. Each new injection of magma into El Hierro volcano means more earthquake activity. Inflation is also rather high at the moment. But it is around 120mm so far (that number has changed. I just do not have the most recent information on inflation). This gives a clue of amount of magma that is currently resting inside (short of) inside El Hierro volcano sill. If all of that magma is going to erupt is a question that I do not have any answer with. But if it does. That type of eruption might last months to years if it is a slow on. If it is a large fast eruption. It is going to last few hours. But all such thinking is just speculation and nothing else.
Currently the activity in El Hierro volcano is more quiet (as of when I write this blog). But that might change at any time as has become clear in the past few days. I expect the current level of activity to continue. How long it is going to continue as it is now is impossible to know. It stops when it stops. That is my best answer into this question.
Overview of the earthquake activity during the past few hours. What is interesting on this image is the cluster of earthquakes at 10 km depth at the most distance from El Hierro volcano. If that blob of earthquakes manages to break to the surface and erupt. It would not make any difference to the El Hierro Island. Since the depth at this location is around 2 to 3 km. Copyright of this image belongs to IGN.
What is interesting on this image is the pattern of earthquakes that have taken a short of “U” turn. I do not know why this is or what it is going to do. More explanation on this image below. Copyright of this image belongs to IGN.
Expiation and interpretation on the image above with the earthquakes from the year 2011 is here below.
But it is worth keeping a eye on this. This image also suggests that the new magma injections that are creating this earthquake swarms are coming from the central dike intrusion in El Hierro volcano (the big blob in the center of the El Hierro volcano). Rather then anywhere else under the volcano. The lack of earthquakes in the center also suggests well established magma pathways for the magma to flow trough. If that is good or bad news I do not know yet. But this suggests that current magma injections and inflow into El Hierro volcano are far from over and might last a lot longer then current ideas suggests. Even if there has not been any major eruption so far in El Hierro volcano.
There are currently now 4 well established magma sills in El Hierro volcano as can be seen above. Three of them are large, one small and one failed sill (to the east) also. There is a chance of more smaller sills without me seeing them in the current data. They might simply just be hiding in the earthquake swarms. This sills are going to erupt magma once it is ready to do so. If this magma ever reaches that stage to start with. If that is going to happen is impossible to know until it happens.
At last. Here is a video of rockfall in El Hierro Island due the magnitude 4.7 earthquake yesterday. As before. I urge people to avoid rock belts in El Hierro Island due to this risk of falling rocks due to earthquake activity.
I am going to continue to write about El Hierro volcano as things happens. But I am doing my best to cover this. Even if I do not understand a lot of Spanish (so far) and I do not know where to search for news in Canary Islands. I have few media outlets to read. But so far not many to give me good idea of the effect this is having on people in this area. As before I urge people to take care of them self and not to take any risk and prepare for earthquake activity and possible eruptions. Just in case. Since it is better to be save then sorry when it comes to active volcanoes.
Spanish news that I know about