Monitoring the reawakening of Canary Islands' Teide Volcano



Following more than 30 years of seismic and volcanic quiescence, the Canary Islands region located off the northwestern coast of Africa started to show signs of seismovolcanic activity at the end of 2003 (Figure 1). In spring 2004, there was a significant increase in the number of seismic events (a mixture of volcano-tectonic events and regional earthquakes with pure volcanic events such as tremors and long-period signals) located inland on Tenerife Island.

The increase ofactivity in 2004 coincided with an increase of fumarolic activity at the Teide volcano on Tenerife Island, an increase in the emission of carbon dioxide in the northwestern part of the island, and changes in the gravimetric field on the northern flank of the volcano. After several seismic events had been felt by the population, the first alert level was declared by the civil protection division of the local government.This apparent reawakening of Teide, which last erupted in 1909, provides an opportunity to study from the initial stages the reactivation of this volcanic area and its related phenomena.