El Hierro Update — New Earthquake Swarms

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El Hierro Volcano : Green pre-alert – A new earthquake swarm has started below El Hierro – 40 earthquakes until 13:47 UTC

Last update: August 16, 2012 at 4:32 pm by By

Update 16/08 – 16:25 UTC
– 3 more earthquakes from M0.9 to M1.1 at a depth of 11 to 12 km (12:25 to 13:47 UTC)
– Maybe IGN could take a few courses in press reporting at GNS Science New Zealand. If an important new swarm starts, like the one today (even with weak earthquakes), an experienced volcanologist may write 5 sentences in explaining what the opinion of the organization is. Why does a body like Pevolca is to be used for volcanology ? If i would live in Sabinosa, i would love to hear a few words  if continuous quakes are occurring below my house.

Update 16/08 – 13:37 UTC
– 5 more earthquakes in between M0.6 and M1.2 and at depths in between 10 and 11 km

Image courtesy Avcan

Update 16/08 – 11:53 UTC
– We have to continue bringing updates on the seismicity below the island.
4 more earthquakes bringing the total on 32 today. Magnitudes from M1.0 until M1.5. Depths 10-11 km. IGN has updated his list up to 08:30 UTC
– At right a small map with the epicenters of a number of the latest earthquakes.

Update 16/08 – 09:50 UTC
– 1 earthquake has to be added since our latest update (07:29 – 11 km depth – Magnitude M 1.5)
– For your comfort, we have cut 2/3ths of this article. Parts 49 and 50 (yes 50!) have been archived. Links to all those 50 parts can be found at the bottom of this page.

The latest 10 earthquake epicenters – image ourtesy Avcan

Very important Update 16/08 – 08:19 UTC – A new earthquake swarm has started below El Hierro
– For the 3th day in a row the number of earthquakes are fundamentally increasing below El Hierro. Although not official, we think that speaking of a new earthquake swarm is the only right way of describing the current set of earthquakes.
– No less than 26 earthquakes occurred this morning (from midnight UTC until 07:00 AM)
– The majority of the earthquakes are still weak, but the M2.2 from early this morning was the strongest in a while and the Magnitude pattern tends to become stronger every couple of hours.
– The CHIE seismogram is not showing a lot of action, but the M2.2 can well be seen. CHIE is not the best station at the moment to show the seismic events at his best.
– The depth is continuing around the 10 to 12 km which is a complete difference from the July swarm, but still far away from an eruption. More seismicity at lesser depths is needed to create a pre-eruptive condition. Newt to seismicity, we have also the gas analysis, the deformation, etc who will have to confirm if the present swarm will end in an eruption. The magma pressure should be powerful enough to find his way up.
– We do not know how many  University of Nagoya GPS stations are still working, but we know for sure that FRON station still works and shows a vertical increase of many mm, which sounds normal after the present set of increasing earthquakes in the area.
– A reason for concern at this time should be the location of the seismicity (El Golfo Bay and Sabinosa area – including the cliffs south of Sabinosa). Landslides and rockfall may become dangerous at Magnitudes from M4 and up.

for more information, history, and updates, go to:    http://earthquake-report.com/2011/09/25/el-hierro-canary-islands-spain-volcanic-risk-alert-increased-to-yellow/