Earth tremors in Valencia were caused by undersea gas plant, report confirms

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http://elpais.com/elpais/2014/05/13/inenglish/1399985800_578190.html

An official report has officially confirmed for the first time that there is a “direct relationship” between the 512 earth tremors recorded in Vinaròs in Castellón province last September and the injection of gas into the nearby Castor offshore storage plant. The National Geographic Institute (IGN), one of two public organizations asked by the government to conduct a detailed study into the causes of the quakes in the Valencia region, concluded: “Everything indicates that the induced seismicity is the result of gas-injection activity.” Local residents felt 15 of the tremors, the biggest of which measured 4.2 on the Richter scale. The government ordered activity at the plant to be stopped on September 26 last year, after the first 200 quakes.

Making use of a depleted oil field 1,700 meters below the sea, the Castor gas-storage plant was being built to hold a quantity of natural gas equivalent to the country’s total consumption over a period of 17 days, in order to cover spikes in consumption levels and interruptions to the supply. Liquid natural gas is supposed to be piped into the empty Vinarós Castellon oil field, via a 13.6-mile-long offshore pipeline. A 19-bank international consortium, five of whose members are Spanish, provided the $1.6 billion in financing for the project.

The IGN report ruled out that the seismic activity had its origins in the Amposta fault line – upon which the plant is built – as was first suspected. “We’re dealing with another fault, one that is not mapped,” it said. “The injection of gas has accelerated a seismotectonic process with a build-up of forces that already existed in the area, but that had not been categorized before,” it added.

Two other big fault lines, plus many other unmapped, smaller ones, also lie nearby. Several geologists consulted by EL PAÍS pointed to these as to blame for the quakes several months ago. One of them, according to the IGN report, has a “direct relation” to the seismic activity.