Troops from the Military Emergency Unit (UME) left Tenerife at midday on Wednesday, bound for El Hierro. There they will be used to assist a possible evacuation of the 10,000 or so residents should there be a volcanic eruption on the smallest Canary island. Seismic activity, which was first flagged up as a risk in July, has been getting strong enough since the weekend to warrant concerns that magma is working its way to the surface.
After seismic activity rose on Tuesday, the authorities evacuated around 53 people, as well as closing the main tunnel on the island, which links El Hierro's two biggest towns.
The National Geographic Institute (IGN) is studying whether the magma below El Hierro - which, like the entire Canary Islands archipelago, is volcanic - is rising to the surface. The seismographs that are located around the island registered an earthquake measuring 2.3 on the Richter scale at 3.59am on Tuesday, at just two kilometers of depth.
Such a shallow seismic event would suggest that an eruption may be close, but scientists have been quick to point out that the figure is provisional and has yet to be confirmed. Until Tuesday all of the seismic activity had been detected between 12 and 15 kilometers of depth.
Up until 8.30am on Wednesday morning, a total of 22 seismic events had been registered on El Hierro that measured between 1.6 and 3.3 on the Richter scale, according to the IGN. The strongest was detected at 5am, and measured 3.3. It was located at 15 kilometers of depth in the southwest of the municipality of Frontera. An hour before, another tremor came in at 3 on the scale, while at 12.02am another measured 3.1.
In response, the Canarian government sent a fax to the Defense Ministry requesting assistance from the UME, in case a full-scale evacuation becomes necessary. At midday a boat left the Tenerife port carrying 31 soldiers and six trucks, four buses and two off-road vehicles. They also have with them a field tent with a capacity to shelter 2,000 people. Defense Minister Carme Chacón also headed to the island on Wednesday afternoon, to supervise the evacuation measures.
According to Chacón, the UME will be under the orders of the Canarian authorities, and their numbers will be boosted should the situation become more serious. The minister also called for calm among the population, saying that the unit's task was one of "prevention."
The first evacuations took place at 10pm on Tuesday night, when the Civil Guard began to tell families in four areas of the municipality of Frontera, in the north of the island, that they had to leave their homes due to fears of landslides.
"We've grabbed the bare essentials and we're going to my brother's house," explained local Mari Paz. The residents of the Las Puntas, El Lunchón, Los Corchos, Pie Risco and Guinea neighborhoods were evacuated from their homes. The Red Cross has sent a boat filled with aid for the 50 or so evacuees.
Scientists from the National Geographical Institute are traveling from town to town on El Hierro to explain what might happen, to calm the population and to answer their questions. What's more, Canarias Civil Protection has prepared a unit so that, in the worst case scenario, 4,000 people can be evacuated in four hours. Shipping companies and airlines that operate in the Canary Islands have already been contacted so that their ships and planes can be used in case of a volcanic eruption.
The majority of the seismic activity has been imperceptible for the 10,000 inhabitants of the island, with only around 15 of the 8,000 tremors registered since July 19 being noticeable. But the growing intensity has raised the sense of alarm among the population. "We can't fight against nature," said local resident Arminda Pérez Casañez.
Only one eruption on El Hierro has ever been recorded, in 1793. It lasted for a month.