Updated 5 October 2pm: Involcan says that the most significant conclusions from its initial analysis are that the cluster can be formally classified as long-period seismic-volcanic events, with the initial records underestimating the number of tremors which could actually have been over 400, forming a continuous stream for an hour and a half from 6pm on Sunday.
Involcan continues that the apparent line of the tremor points is probably more a product of the location of the measuring points, with the tremors being more in a cluster than the image suggests, and the depth is almost certainly not as deep as the minimum 10km declared by IGN. The spectra show similarities with those of other long-period events, which occurred most notably in Tenerife in 2004.
Involcan says that it must insist, once again, on the complete absence of an “action-reaction” sequence to this phenomenon, and on the need to avoid baseless alarmism. Involcan says that these phenomena can go as quickly as they come without any related activity, and that it is continuing to research and will communicate any relevant information as appropriate.
The Instituto Geográfico Nacional for its part has concluded that the “micro-tremors” are of a volcanic nature, and that although their exact cause is unknown, their behaviour is within the range of “normal” for an active volcano. IGN has taken part in a meeting of the Comité Científico de Evaluación y Seguimiento de Fenómenos Volcánicos as part of the application of PEVOLCA, which I described in the 4th October update below, and says that the release of energy in the clusters is extremely small, so that we are far from a possible eruption. IGN confirms Involcan’s information that no deformation has been detected, and that these are typical and normal occasional events. The Institite will also be continuing its researches over coming days and weeks.
I have also been contacted by a fully qualified professional geologist and vulcanologist who says that low magnitude earthquakes occur all the time, and are a sympton of a dynamic planet. He stressed that any explosive eruption in the future would almost certainly be measurable in geological ages rather than human years! He said that current signs do not point in that direction at all, and could not suggest an eruption without the tremors starting to coalesce towards Teide.
His advice, like that of Involcan, IGN, Avcan, the Tenerife Cabildo and the British Consulate – to whom I’ve spoken in the last few minutes – is to stay calm and carry on as normal, because in Tenerife terms, all is actually “as normal”.
The Tenerife Tourism Corporation, a public entity under the Tenerife Island Government, wants to refute the incorrect information recently published by some British media in which it is stated that a volcanic eruption in Tenerife is imminent.
Such information is untrue and not based on any official reports or data. Both the Volcanology Institute of the Canary Islands (Involcan) and the National Geographic Institute (IGN) – official sources on this matter – report that the island experienced a series of micro earthquakes, following a northeast-southwest direction, in the early hours of last Sunday. None of them were detected by the people of Tenerife and, as confirmed by the IGN, they were not due to any seismic activity but to low intensity tectonic movements.
Involcan states that the tremors could be related to the hydrothermal system of the volcano, and not to a magmatic intrusion, which would, in any case, be a “common situation which should not frighten anybody”.
Due to its volcanic origin, Tenerife is continuously monitored and any seismic activity associated with magma would be detected in very early stages. It is worth pointing out that the last volcanic eruption that took place on the island happened over 100 years ago, causing no personal injuries of any kind.
Therefore, everything is as calm as usual in Tenerife; there have been no changes related to these micro earthquakes and there are no current risks. Everyday life remains the same in the island’s cities, towns and tourist areas – the situation is totally safe. The Tenerife Tourism Corporation advises obtaining information exclusively from official sources rather than from sensationalist articles to avoid unnecessary fear and confusion.
Updated 2pm: The Tenerife Cabildo has issued the following statement (click the image to see full size). I’ll get a translation on here in due course but the gist of it is that it deplores the articles today in the British press, i.e. the Express and also, now, it seems, The Sun, which have sensationalized the cluster episode here for their own purposes with absolutely no regard for truth or fact. The Cabildo confirms what I’ve already said in previous posts, that not one element of the tremors has been perceived in any way by any of the public, and that they are very likely related to hydrothermic systems rather than volcanic ones, and do not represent any sort of threat to public safety.
Updated 12.30pm: As a point of interest, and nothing more, a new cluster of tiny tremors started to be registered at 7am today, Avcan reports. The tremors stopped around 9am and then resumed half an hour later and are still continuing at the time of posting. These tremors are below the level which IGN now records, and again there is no cause for concern … and these tremors are far too low to be felt, heard or otherwise perceived by the public.
Updated 4 October: Although Involcan is still continuing its research into the cluster, the Daily Express has excelled itself by reporting panic in Tenerife because “Teide’s about to blow” (link). And so, just to reiterate …
The “cluster episode is over”, Involcan says, and is almost certainly connected to hydrothermic, rather than volcanic, activity: in other words, there is no risk of an eruption. Moreover, the cluster was of tremors at a depth of between 10 and 40km, and magnitude <1, which means they were unperceived – and unperceivable – to anyone. They were registered by machines, and the following video from Actualidad Volcánica (Avcan) reproduces what they sounded like after the inaudible data values were converted to sound waves, a process known as audification.
The Express article also attempts to cause fear by implying that there is neither programme nor education about what to do in the event of an eruption, nor an evacuation protocol. All of these claims are false. The Canarian Government held its latest of several simulation exercises only two years ago, imagining an explosive grade 5 eruption from Teide’s Pico Viejo (link). In terms of education, documents are made available to schools by Protección Civil like THIS one: these things are taught to the public here from childhood!
Finally, the idea that “we need a plan” is idiotic. There is already a plan, a protocol, and a Government agency in place. We live on an active volcano so the idea that people are whistling into the wind and living on hope is simply insulting to the authorities here. The Canarian Government’s Plan Especial de Protección Civil y Atención de Emergencias por riesgo volcánico en la Comunidad Autónoma de Canarias (Pevolca) is enshrined in legislation, and annex 2 of the document is a public information and advice leaflet: you can read it HERE.
Updated 3 October: Involcan says that no seismic movements were registered throughout the night, and so the “cluster episode” is over. The institute assures the public that although interesting, such clusters are no cause for alarm, being typical of active volcanoes. Their relative rarity in Tenerife, however, obliges vulcanologists to study yesterday’s cluster.
Involcan confirmed that what can be said at present is that GPS stations show no deformations, which suggests no injection of magma into the subsoil, and further, that the cluster is related more to Teide’s hydrothermal system. Further analysis will be carried out in this respect throughout today. Involcan’s two teams are already on site studying carbon dioxide emissions.
The institute reiterates that although yesterday’s cluster was “an anomaly”, it represents no cause for alarm, and that in no case is there an action-reaction sequence. What such clusters show is the dynamic systems of active volcanoes such as Teide. Involcan says that it will release more information as it becomes available.
Original post 2 October: Instituto Volcanológico de Canarias says that although they were all minor, there has been a series of earthquakes in west Tenerife today. Involcan says that these are typical of those produced in active volcanoes, and the number of tremors is still waiting detailed analyis, but the event can be classified as a “seismic cluster” on a NE-SW alignment, with some 90 tremors being recorded between lunchtime and 10pm. Involcan says that it is continuing to monitor the activity and is organizing two working groups which are being sent to the area tonight.