Concern in the Ebro Delta over a series of small earthquakes allegedly due to a gas offshore platform
A series of earthquakes measuring between 2 and 4.2 on the Richter scale have been affecting the coast of southernmost Catalonia and northernmost Valencia in the last few weeks but particularly since last weekend. All the evidence suggests that the Castor offshore gas reservoir is behind the earthquakes. In 2009, the Spanish Government approved the building of an underground gas reservoir located under the sea bed, some 20 kilometres offshore from the Ebro Delta and Vinarós, using the cavity in the rock from a former oil field. Madrid approved the project without an earthquake risk report, despite a formal petition from the Catalan Government. Now, geologists, the Spanish Industry Ministry and the company admit that the injection of gas into the rock could be triggering the earthquakes. Activities have been stopped and the Public Prosecutor’s Office is investigating the case.
Barcelona (ACN).- In the last few weeks, but particularly since last weekend, a series of earthquakes, measuring between 2 and 4.2 on the Richter scale , have been affecting the coast of southernmost Catalonia and northernmost Valencia (also called Valencian Country). All the evidence suggests that the activities of the Castor offshore gas reservoir are behind the earthquakes. In 2009, the Spanish Government approved the building of an underground gas reservoir located under the sea bed, some 20 kilometres from the Ebro Delta and Vinarós shores, using the cavity in the rock from a former oil field. This is a scandal because Madrid approved the project without an earthquake risk report, despite a formal petition from the Catalan Government, which had also issued negative environmental reports and refused to allow the construction of this infrastructure in its territorial waters. The offshore platform injecting the gas into the rock was finally built in Valencian waters, but immediately next to Catalan waters. Now, geologists, mining engineers, the Spanish Industry Ministry and the company owning the Castor project say that the injection of gas into the rock could be triggering the earthquakes. As a precaution, activities have been stopped and the Public Prosecutor’s Office is investigating the case. The Catalan Government announced on Friday that it will be handing all the documents it has about the project to the Public Prosecutor’s Office on Monday and Tuesday. Neighbours are significantly concerned since an earthquake of 4.5 degrees can start causing minor material damage and geologists do not rule out the possibility of registering such earthquakes or stronger ones in the coming weeks.
This Friday morning, two earthquakes of 3.7 and 3.6 degrees on the Richter scale were registered in the Ebro Delta, after a night with several small tremors of between 1.6 and 1.7 degrees. However, all the alarms were activated on Tuesday morning, when a 4.2 degree earthquake was registered. So far, this has been the most intense, but the earthquake activity has been carrying on for more than four weeks, with several small quakes each day, some of them perceived by the population. People of the Ebro Delta are expressing their concern and outrage about the situation.
The Catalan Government asked for an earthquake risk report but the Spanish Executive ignored the petition
All the experts, even from the Spanish Government and Escal UGS – the company owning the Castor project – admit that the earthquakes are very likely related to the gas injection activities in the former oil field Amposta. Escal UGS is owned by the Spanish construction company ACS (66.67%) and by Canadian CLP (33.33%). ACS is one of the main private companies in Spain, with projects worldwide, and its president and partial owner chairs Real Madrid football club. The project was approved by the Spanish Industry Minister without an earthquake risk report, despite the formal request from the Catalan Government. In fact, the Catalan Executive had denied Ecal permission to build the project in Catalonia’s territorial waters, as it was not fully convinced about its environmental impact, particularly regarding seismological activity. However, the regional government of Valencia welcomed the project and the offshore platform was set up in Valencian territorial waters, but immediately next to Catalonia’s. On top of this, the Spanish Industry Minister, which was run at the time by the Socialist Party (PSOE), decided to ignore the request for earthquake risk reports. The project was approved with an environmental report highlighting the potential impact for sea mammals and turtles, but not potential earthquakes. The Spanish Government stated this week that the project fulfilled all the legal requirements and that a seismological risk report was not required.
The Castor project
The Castor project consists in building a gigantic underground reservoir to store gas in periods of low demand to use in demand peaks. Castor was planned to contain a third of Spain’s entire gas demand for 50 days. Around 1.8 million cubic metres of gas would be stored and 1.3 million could be used. The gas would occupy the space of a former oil field, located 1.8 kilometres below the sea bed under a layer of impermeable rock. It would be injected by an offshore platform located some 22 kilometres from the sea shore. The gas would be transported through a pipeline from a treatment plant located near the coast. In periods of low gas demand, such as summer months, gas would go from the coast to the platform and then be injected underground. In periods with high demand, the process is reversed. Gas injections started this summer for the first time.
Why the gas injection causes an earthquake
The space where the gas is injected is currently occupied by sand and water, from a lower aquifer. In addition, the space coincides with a geological fault, as experts say it favours the sealing of the reservoir. The gas needs to be injected using high pressure to remove the water and make it return to the lower aquifer. Such high pressures create tension in the impermeable rock on top of the reservoir, which is then released through small earthquakes. Furthermore, the fault might have been activated. The company admitted on Thursday that small earthquakes were to be expected as a matter of course, but it also said they were not expecting such intense ones.
Geological experts confirm the link between the Castor activities and the earthquakes
Several geological institutes have confirmed that the gas injection activities are almost certainly behind the earthquakes. The seismological expert of the Ebro Observatori, Estefania Blanch, pointed out that the earthquakes could carry on for days or even months, even though the gas injection has been stopped. She mentioned a similar case in Russia, when earthquakes lasted for several months. However, the experts from the Spanish Geological and Mining Institute, which is part of the Spanish Economy Ministry, said on Friday that earthquakes would probably decrease in number and intensity in the coming days. Despite this affirmation, they also added that they cannot rule out the possibility of having earthquakes stronger than 4.5 Richter degrees, which could start causing small material damage.
According to the Spanish Government, the company is doing things right
The Spanish Industry Minister, José Manuel Soria, affirmed that the company followed all the legal requirements when presenting the project. In addition, he stated that the environmental impact report was not obliged to include a seismological risk assessment, and emphasised that the company is also respecting all the regulations in its gas injection activities.
The Public Prosecutor has launched an investigation
Inspectors of the Ministry travelled to the offshore platform on Wednesday to verify that the activities had been stopped. In addition, this Friday a helicopter of the Guardia Civil landed on the platform, a few hours after the Public Prosecutor’s Environmental Office decided to investigate the case. On Friday evening the Catalan Government offered full co-operation and announced that it will hand all the documents it has about the case to the Prosecutor’s Office. Besides, the Catalan Executive decided to activate the earthquake risk plan (a Civil Protection plan) in the Ebro Delta area on Thursday evening, in order to reassure the population. The Catalan Home Affairs Minister, Ramon Espadaler, complained that the Spanish Government’s “lack of transparency” and “opacity” regarding this whole affair was “a shame”.