This is a update on El Hierro volcano activity.
The largest earthquake in El Hierro volcano happened today (31.03.2013) at 10:59 UTC. This earthquake was clearly felt in El Hierro Island. It also caused rock slides and other loose material to move in rock belts are all over El Hierro Island. I have not seen any news about damage followed by this earthquake. There might not have been any. As the earthquake took place about 20 km away from next populated area. The magnitude of this earthquake was ML4.9 (Mw4.6), it had the depth of 20 km. Earlier at 09:40 UTC a earthquake with the magnitude 4.5 had taken place. Following this two earthquakes there have been over 10 earthquakes with the magnitude 3.0+. The number of smaller earthquakes is in the hundreds or even thousands. I am not sure on that detail at this moment.
So far no eruption has started in El Hierro volcano and there are no signs if harmonic tremor pulses taking place at present time. That might change if the magma finds a path to the surface. So far that has not happened. The center of the earthquake activity is currently far away from dry land. But it is about 20 km out in the ocean where the depth is around 2 to 3 km.
Here are two videos. The first one shows the rock fall following the magnitude 4.9 earthquake. The second video is the news in Canary Islands on this events. Both videos are in Spanish.
Canary Islands news.
More Spanish news on this events can be found here.
El IGN revalida el seísmo de 4,9 en El Hierro, el más fuerte hasta la fecha (Spanish)
As before I urge people not to be close to rock belts on El Hierro Island because of risk of land slides and falling rocks following earthquake activity in El Hierro volcano. Currently the earthquake activity in El Hierro volcano is ongoing and does not show any signs of stopping soon. When this activity is going to end I have no idea. For the moment the best thing that can be done is to monitor the activity and try and see where it is going.