Unusual series of earthquakes

The latest tremor (above, red star marks epicentre) occurred late at night on the first of November 2023, again near the island's capital San Sebastian de La Gomera and was of 2.5 magnitude.The other markers show where and how intensely it was felt by the population.  (Source: IGN)

There has been a series of minor earthquakes reported by the Spanish agency IGN (Instituto Geografico Nacional) in or very close to La Gomera , some of which were widely felt all over the island. Most were on the eastern side near the capital San Sebastian de La Gomera. This somewhat unusual event began last Saturday night and by Monday about 15 minor quakes up to magnitude 2.8 on the Richter scale had been reported by IGN. Some of these quakes were widely felt across the island with reports of the typical low rumbling noise that accompanies earth tremors also coming from various parts of the island. Even the director of the Canarian branch of IGN, Itahiza Dominguez, called these events ''un poco anomala'' ( a bit abnormal) when asked for an explanation by the press. She also said that since the installation of the latest seismograph in La Gomera in 2017 there had been only 17 earth tremors registered by said station previously.

More than that six year total has now occurred in the past few days. However, La Gomera has been volcanically 'dead and cold' i.e. inactive for more than a million years. As it is one of the oldest Canary Islands in origin, the latest activity is unusual and probably points to tectonic movements of some kind, according to Dominguez.

The depths of the epicentres initially were between 10 and 23 kms, but the latest quakes had their origin only 4 to 8 kilometres underground.

There's a rumour going around that the seismograph was triggered by undersea cable laying preparation works for the electricity inter-connector between Tenerife and La Gomera, which is to come ashore in the municipal area of San Sebastian de La Gomera, causing the rumble similar to those heard and felt across the island. It has also been known that very heavy swells at sea pounding La Gomera's coastline will cause the sensitive seismic station high in the mountains of La Gomera's Garajonay national park to register tremors, as do rock blasting operations and tunnelling for roads. However the scientists at IGN are no fools and usually are wise to these causes. They will not report those tremors  as earthquakes and won't list them in their bulletins. 

Overall, La Gomera remains one of the safest places in the Canary Islands in general and seismically in particular. Maybe the vibrations were caused by some blown-in minstrels blowing their didgeridoos too enthusiastically...

Closer but insignificant quake off north coast

Just a few days after the locally felt tremor off the north-western coast of La Gomera another seismic tremor averaging just 1,6 (with a peak value of 2,2 mbLg at GOM station) on the Richter scale was registered less than 25 hours ago a short distance off La Gomera's north-north-eastern coast in a depth of 15.2  kms. Quakes of such a minor strenght are inappreciable and happen frequently in and around the Canary Islands, but are rare near La Gomera's coastline. Read more...

Minor earthquake felt in La Gomera

The red star (left) shows the epicentre of the minor earth tremor

A minor earth tremor averaging 2.8 on the Richter scale occurred at a depth of only eight kilometres in the Atlantic very close to La Gomera's west-north-western coast at around 11:10 pm late Tuesday night, January 22nd 2019

This is nothing to worry about, as La Gomera's former volcanoes are long extinct and the island has not experienced any volcanic activity for far more than a million years, being one of the oldest islands in the Canaries. La Gomera existed long before the volcanically very active neighbouring island of El Hierro was even born. However, the abundant seismic activity in and around the Canary Islands rarely comes as close and in such shallow depth as Tuesday night's minor earth tremor.

Generally volcanic activity in the Canaries is of a 'mild nature', but magma movements deep under and around the Canary Islands cause regular tremors. It is however a rare occurrence that such a quake is registered by the seismic station situated in the mountains of the national park with an epicentre so close to La Gomera, and last night's tremors were felt by the population in La Gomera's sparsely populated west and north, see the pointers in the map above, which the show locations of verified reports published by the Spanish National Geographic Institute (IGN). This quake also registered at all seismic stations in neighbouring islands, with the peak value 3.9 having been recorded at the station in La Gomera (EGOM)  a few seconds before 23:10h, at the start of the tremor.

The last minor quake recorded close to La Gomera was recorded in September 2017, see previous post...

Evento	Fecha	Hora UTC	Hora Local (*)	Latitud	Longitud	Profundidad (km)	Magnitud	Tipo Mag.	Int. max.	Localizacion
es2019apdcj	22/01/2019	23:09:47	23:09:47	28.2262	-17.5079	8	2.8	mbLg	II	ATLÁNTICO-CANARIAS

Earthquake felt in Tenerife and Gran Canaria

The red star shows the epicentre and the pointers indicate locations where the quake was reportedly felt

A 4.2 magnitude earthquake was felt his morning at 6.36am according to the Spanish National Geographic Institute (IGN). The institute's stations spread across the Canaries registered a seismic movement with its epicentre located in the Atlantic between the islands of Gran Canaria and Tenerife, at a depth of 14.3 kilometres.

The tremors which lasted about one minute were felt in several municipalities of both islands and some people there were woken up by the quake. According the National Geographic Institute’s records, the earthquake reached a peak magnitude of 4.6 within a few seconds of starting. Another three very minor quakes were detected in the same area at between 1.7 and 1.9 magnitude before the stronger one. There were no reports of any damage.

The sea area between these two islands experiences minor earthquakes very regularly and today's slightly stronger one would still be seen as part of normal seismic activity in this area, so please ignore any alarmist reports that some irresponsible media sources have published (e.g. The Express (UK) ran the sensationalist headline: ''TENERIFE EARTHQUAKE: Atlantic smashed by 4.2 magnitude quake near La Palma volcano''.) Yeah La Palma, where doom to 'smash' us all is supposedly brewing below the surface, had to be mentioned again. Sorry but the only word for that headline, and for the La Palma doomsday scenario hype of a few years ago, is BULLSHIT !

Minor earthquake close to La Gomera

Evento	Fecha	Hora GMT	Hora Local (*)	Latitud	Longitud	Profundidad (km)	Magnitud	Tipo Mag.	Int. max.	Localizacion
es2017ldmmo	17/09/2017	20:49:03	21:49:03	28.1755	-17.1168	9	2.0	mbLg		E AGULO.IGM

A minor earth tremor of 2.0 on the Richter scale occurred at a depth of nine kilometres close to La Gomera's north-eastern coast at around 9 pm on Sunday night, Sept. 17th 2017.

This is nothing to worry about, as La Gomera's former volcanoes are long extinct and the island has not experienced any volcanic activity for far more than a million years, being one of the oldest islands in the Canaries. La Gomera existed long before the volcanically very active neighbouring island of El Hierro was even born.

Generally volcanic activity in the Canaries is of a 'mild nature', but magma movements deep under and around the Canary Islands cause regular tremors. It is however a rare occurrence that such a quake was registered by the seismic station situated in the mountains above the town of Agulo with an epicentre so close to La Gomera.