Monday, June 25, 2012

El Hierro Not Finished Yet?

The volcanic island of El Hierro, part of Spain's Canary Islands, is showing increased signs that it is again gearing up for some activity. According to IGN and, there were over 104 magnitude 2 or above quakes at the island yesterday alone. This is on par with the amount of quakes that preceded the previous and all but over eruption of the submarine volcano off the coast of the town of La Restinga. The below YouTube Video is an animation of the quakes in sequence and magnitude.

The activity currently being experienced is almost certainly related to further dike intrusion underneath the volcano, and a likely precursor to future activity on the island. The Spanish government had previously declared the eruption over, despite occasional underwater bursts from the small submarine cone that was constructed over around a year. Harmonic tremor had all but disappeared, leaving only a weak signal. But the volcano never truly stopped its activity. Degassing and other emissions are still ongoing, and those who know are still certain that El Hierro is far from done.

The location of the current swarm of quakes suggests that next time El Hierro erupts, it might not be underwater this time. So far, Pevolca, INVOLCAN, and IGN have all been mum on the quakes, saying only that they are monitoring the situation in real time. It is of some concern that the small cone which has ceased erupting is probably blocked form doing so again, so the question now is where can/will the magma release? If it can't go the same direction, it will go another.

At last glance, the quakes are still ongoing, with some above magnitude 3.0. If they rise to 4.0, 5.0, or higher, the island may very well have another situation on their hands. I will return to active monitoring of this volcano, as it appears things are changing quickly. The below photo is a real time (for today) seismic graph. It's starting to look pretty familiar.


  1. this should be taken very seriously

  2. It should be a cause for caution and preparedness, never panic. There is no current signs that an eruption is imminent, however at this point the likelihood has gone up tremendously.

  3. As a follow-up, the swarm intensified int he late hours of today. The activity is increasing.


Comments are moderated. See the comment policy for details.