Seismic unrest at El Hierro Island (Canary Islands): updates Jan-March 2013
New earthquake swarm
Update Mon 18 Mar 18:27
Location of today's quakes at EL Hierro (IGN)
Seismic signal from El Hierro (IGN)
A powerful new earthquake swarm accompanied by volcanic tremor has started under the western part of the island. So far, the quakes are mostly at about 20 km depth. A plausible cause is that another magma intrusion from the mantle into the crust under the island has just started.
Update Sun 10 Feb 12:51
Depth vs time of recent quakes under El Hierro
The number of earthquakes continues to be a bit above background with 1-6 small daily events.
Second submarine eruption during 2012 ?
Update Fri 08 Feb 09:25
Some new data suggest that a second submarine eruption might actually have occurred at El Hierro occurred at the sea floor SW off El Hierro Island during the strong seismic crises in end of June - July 2012.
Evidence of this claimed eruption were sonar images which, according to the researchers, showed volcanic material erupted in an area less than 2 NM from the coast and at depths of 64 to 88 meters. The material formed a plume that rose up to a depth of 48 meters. However, some doubts about this evidence remain because while the earthquake swarm was very intense, there were no shallow earthquakes associated with the possible opening of a new eruptive vent. Read all
Read more about the June-July 2012 seismic activity
Earthquake depth distribution 1 June - 23 Aug 2012 showing the strong seismic swarm at around 20 km depth end of June-early July and the smaller swarm at around 10 km depth in mid August
Update Mon 28 Jan 17:06
Slightly elevated earthquake activity continues.
Time and depth of recent earthquakes at El Hierro
Update Sat 26 Jan 12:51
Map of recent earthquakes at El Hierro
Small earthquakes have started to occur again in increased numbers. Following a period of calm with many days without any quakes, about 9 small quakes in the range of magnitude 1-2 have been recorded over the past 48 hours. Most of them were located at depths of 10-15 km depth under the central part of the island.
Update Fri 04 Jan 10:30
It seems that the swarm has already ended.
Inflation visible, suggesting magma intrusion
Update Thu 03 Jan 11:54
GPS data from El Hierro - note the inflation visible at station HI00
Location of GPS stations (IGN)
Earthquakes continue under in the eastern El Golfo area. GPS station HI00 in the NE part of the island shows a clear inflation, which suggests that some magma intrusion has been taking place. The tremor signal recorded by IGN is low.
New seismic swarm
Update Wed 02 Jan 09:58
Locataion of recent quakes (IGN)
Time and depth of recent quakes under El Hierro
A new swarm of earthquakes started on 31 Dec. Most quakes are located at 15-20 km depth under El Golfo and seem to propagate slowly towards the east. On 31, 57 quakes of magnitudes 1.4-2.4 were registered, on 1 Jan, 43 with magnitudes up to 2.6.