Update 18 February: Yesterday’s tremor off Puerto de la Cruz was an aftershock, scientists think, of an earthquake to the West of El Hierro. A second earthquake in El Hierro the day before yesterday was, in fact, itself an aftershock of the first, and initial concerns at a “revival of seismic activity” are now fading, particularly since seismic readings over the past three days are now considered to be the result of the weekend’s wild weather system. Thankfully, all seems quiet, both in El Hierro and here in Tenerife.
Original post 17 February: An earth tremor of 2.8 was registered just off the coast of north Tenerife at 4.50pm. IGN says that the epicentre was in the sea near to Puerto de la Cruz at a depth of around 28 km.