Potential Magmatic Intrusion Underway at El Hierro?

Each red dot represents an earthquake registered at El Hierro in the Canary Islands from September 13-16, 2012. Most are at depths of 18-22 km below the surface of the island. Image: courtesy of AVCAN. A quick weekend note about a volcano we haven't heard from for much of 2012: El Hierro. Seismicity under El Hierro have increased since September 13 after months to very low activity and since Friday, over 300 earthquakes have occurred. These earthquakes are mostly deep (18-22 km) and under the central part of the island (see above), and have now reached over 115 earthquakes in the past 24 hours. This sharp increase at depth might suggest a new body of magma is intruding underneath the island. Combine that with the observation of deformation of the land surface at El Hierro, and you can be fairly confidence that new material is entering. However, as with any observations such as these at an active volcano, the big question is whether this will lead to an eruption and that is very unclear. Intrusion without eruption happen frequently at volcano, so we may only be seeing the normal activity at a hotspot volcano like El Hierro. Only if the seismicity continues and become more shallow, the deformation increases and the release of volcanic gases such as carbon dioxide or sulfur dioxide increase can we begin to wonder if another eruption at El Hierro is in the works. IGN is monitoring the situation at El Hierro, but not decision has been made to increase the alert status at the island volcano (which currently sits at Semaforo Verde, the lowest alert). You can also check out the seismicity by heading to the AVCAN website.