Geological background

Teide volcano on Tenerife Island (Canary Islands, Spain) is the highest volcano (3718 m) of the Canarian archipelago, the volcanism of which is explained by controversial theories. Fissural eruptions shaped the oldest subaerial part of Tenerife (Old Basaltic Series) between 12 and 3.3 Ma. The central part of the island is occupied by the Las Cañadas edifice, at least 3.5 My old, and associated with a series of shallow magma chambers and to a series of collapses that produced one of the best exposed calderas in the world. The caldera is roughly elliptical, elongated EW and is 16 km x 9 km large. Its base lies at about 2000 m a.m.sl. and is closed off by a huge wall, visible for 27 km along the SW, S-SE and NE sectors.

Teide Volcano and Cañadas caldera photographed by ISS astronauts on
24 October 2002 from an altitude of 383 km. Image courtesy NASA.

A double stratovolcano has formed in the northern border of the Caldera over the last 0.15 Ma: the Teide-Pico Viejo system, characterized by a series of dome constructions and explosive destructions. The two summits are separated by 2.5 km, the highest altitude (3718 m) corresponding to the youngest summit of Teide, an approximately circular cone with a basal diameter of about 5 km. Pico Viejo products, mafic to intermediate composition, occupy the western part of the Las Cañadas caldera, while Teide basaltic and phonolitic products are found in the central and northern part of the caldera, covering its northern slopes.

The subplinean eruption of Montaña Blanca, about 2000 years b.p., marks the latest phonolitic event on the southern Teide flank. Several minor eruptions have been recorded in historical time, involving basaltic magma. The last one occurred in 1909 in Chinyero, near Pico Viejo along the NW-SE ridge. Other historical eruptions include the Siete Fuentes, Fasnia, Arenas and Montaña Negra events in the short period of 1704-1706 and the Chahorra Volcano eruption, at the Teide southern slopes, in 1798.