Mount Teide, Tenerife Island, seismic activity

[Astronuc]

A swell of seismic activity on Tenerife could indicate a long-dormant volcano on the holiday island could be about to blow, with volcanologists warning nearly 100 mini-tremors could signify an upcoming eruption.

Mount Teide, a 3km-high volcano in the south of Tenerife, last erupted in 1909, with an earlier eruption in the 18th Century destroying the town and principal port of Garachico, as well as several smaller villages.

http://www.ibtimes.co.uk/volcanolog...pt-after-100-earthquakes-are-recorded-1584962

Keep an eye on that one.

 

[CapnGranite]

http://www.independent.co.uk/news/w...eports-earthquake-seismic-swarm-a7345921.html
The last time I checked, Dr Pedro Hernandez Hernández, Director of Volcano Monitoring at the Volcanology Institute of the Canary Islands had not posted anything official. Instead, it appears his comments, and those of others, were made directly to the media. This is an interesting phenomenon that seems common in Earth sciences. The media gloms onto the sensational aspects of "warnings" without any effort to put things in perspective. I'm not familiar with Mt Teide to know if this swarm is "abnormal", but no movement of magma has been detected (so far). Geophysicists have been put in a tough spot after the L'Aquila quake in Italy in 2009. Damned if you do report, damned if you don't report. There is a professional responsibility to present both sides objectively, but the problem is that what is understood in terms of uncertainties isn't always understood by the public. The pragmatic lesson learned from Italy is to just shut up after making the initial scientific objective observations. If you were correct in your warning, then you saved the day. If you were wrong about a disaster, are you then responsible for the lost income from tourism and the expense of disaster prep? After L'Aquila, those of us who spent time on the internet (as I did on AOL), were strongly urged by the American Geophysical Union to take a special law course at Columbia University that addressed liabilities and then a short course on legal issues at the AGU meeting in San Francisco. I personally don't know if the swarm was caused by hydrothermal activity, which is common; or if there is any movement of magma or if there is, that the volcanologists missed it. If I was to comment on Mt Teide, I would say that the scientists monitoring it have said that there is no threat of eruption at this time, but they are looking in great detail at the data. If Teide blows soon-ish, well, I guess we still need to work on forecasting.
There should be a section in PF on sensationalized headlines and reports in the media.

 

[Astronuc]

I went to USGS website and did a search on earthquakes of Mag 1 and greater over the last 10 years. They seem few and far between, and only one (Mag 2.8) on the island of Tenerife, but off the east coast.
http://earthquake.usgs.gov/earthquakes/eventpage/usp000fwt3#map
http://earthquake.usgs.gov/earthquakes/eventpage/usp000fwt3#executive

It would appear that USGS has little information on that region, and perhaps the tremors are very low magnitude.

Stronger earthquakes have occurred of the coast west of Frontera, WSW of Tenerife, while various quakes have occurred in the sea between Tenerife and Gran Canaria.

I hope to visit Canary Islands and Azores some day.

 

[CapnGranite]

http://www.involcan.org/noticias/ is a good summary of the events.

 

[davenn]

http://www.involcan.org/noticias/ is a good summary of the events.

unfortunately, can't get that page to load

 

[CapnGranite]

I was having problems with a some of the Spanish and Portuguese seismological sites earlier, but just now this popped up easily on Google. The translation was adequate, but had some flaws.

 

[Astronuc]

I can access the Involcan site.
http://www.involcan.org/actividad-sismica-anomala-en-la-isla-de-tenerife/

En concreto, son 98 pequeños seísmos, que no pasan de los 1,5 grados en la escala Richter, y con epicentros en los municipios de Adeje, Vilaflor, La Guancha, Icod de los Vinos y Arico, pero todos en la base del Teide.

translation "In particular, are 98 small tremors, which do not pass the 1.5 degrees on the Richter scale, and with epicenters in the municipalities of Adeje, Vilaflor, La Guancha, Icod de los Vinos and Arico, but all at the base of the Teide."

So apparently the quakes are low level, < Mag 1.5, so USGS probably doesn't record them.