Seismic risks

Any precautionary measure is justified where seismic activity is concerned. While official confirmation from technical studies has yet to be given, it seems clear that there is a relation between the injection of gas under pressure into an old oil well in Mediterranean waters near the Ebro delta and the frenetic seismic activity in the area over the past few days. Local authorities and residents are understandably concerned about these phenomena and are demanding that the authorities investigate the project fully.

Prudence does not only demand the halting of the injection of gas, as has been ordered by the Industry and Energy Ministry, but also that the necessary geological studies are now carried out to determine with precision whether this industrial activity is the cause of the more than 300 tremors registered. Any study must also quantify the risks involved in the resumption of the fuel-storage process. This is especially important since we have seen that the studies carried out prior to the opening of the Castor Project were not sufficiently rigorous for a scheme of such a scale.

We now know that the environmental impact report approved by the Industry Ministry in 2009 did not include seismic parameters, despite the fact that they had been requested by, among others, the Catalan regional government and the Ebro Observatory. The nature of the activity involved surely warranted such an investigation: we are talking about the injection of high-pressure gas into the disused Amposta oil deposit at a depth of 1,800 meters under the seabed, a rocky structure which was likely to have contracted after extraction and which could easily crack when the gas was introduced.

Fracturing of the rock is the most likely cause of the earthquakes which have been experienced in the area in recent days. The majority have been of low intensity, but the fact that one quake reached 4.2 on the Richter scale — an exceptional reading for the area — suggests that the risk cannot be dismissed lightly. It should be remembered that after 4.5 on the Richter scale, buildings can be affected. The existence of a seismic fault under the storage facility and others nearby raise the uncomfortable possibility that the underground movement in the area could alter the position of the tectonic plates, producing earthquakes of greater intensity accompanied by tsunamis.

The company’s management of the episode has been extremely deficient. It has given the impression through spokespeople that it did have seismic studies, but was unable to produce them. Nevertheless, the company does seem to have been aware of the problem as it had a seismic monitoring system installed.

However important it is to store gas in case of an emergency or supply problems, this activity must always be subject to public safety considerations. In this sense, the government now has two key tasks ahead of it: clarify whether authorization was given to the project in appropriate circumstances, and carry out the necessary studies to establish whether the storage of gas can be resumed with guarantees of safety.