El Hierro Volcano (Canary Islands) : Red alert – spectacular increase of harmonic tremor
Last update: November 20, 2011 at 1:29 am by By Armand Vervaeck and James Daniell
Late night data update 19/11 – 23:16 UTC
– 15 M+1.5 earthquakes today
– Strongest earthquake being a 3.3 at 18:27
– Depth of the earthquakes since midnight : 16 to 23 km
– Harmonic tremor remains strong since 17:16 UTC tonight
– GOOD air quality all day long
Important update 19/11 – 17:46 UTC
– We have just noticed that the harmonic tremor is almost saturated again, the biggest change since the fallback on November 17. The second graph shows the harmonic tremor from November 17 when it collapsed, until the new saturated graph today.
![eh-19112011-2](https://i2.wp.com/earthquake-report.com/wp-content/uploads/2011/09/eh-19112011-2.jpg?resize=560%2C233)
Data update 19/11 – 16:37 UTC
– 10 M+1.5 earthquakes since midnight (a lot less than we have expected)
– Strongest earthquake being a 2.8 at 08:20
– Depth of the earthquakes since midnight : 16 to 23 km
– GOOD air quality values this morning
Update 19/11 – 16:37 UTC
– Ian Carson reports from El Hierro : Civil guard went out to sea in RIB (rigid inflatable) this morning. Spoke to English speaker also aboard. He said ‘volcano quiet today, stain still visible but much lighter than in past ‘Jacuzzi’ times.
for more, updates, and reports, go to: http://earthquake-report.com/2011/09/25/el-hierro-canary-islands-spain-volcanic-risk-alert-increased-to-yellow/