Earthquake Swarm over Mantle Plume Reaches 350 off Coast of Spain
More than 300 earthquakes have struck the Gulf of Valencia, a zone not normally known for seismic activity, over the past month, according to Spain's National Geographic Institute.
The strongest, a 4.2 magnitude earthquake, hit in the early hours of Tuesday. It did not cause any damage…
More than 300 earthquakes have struck the Gulf of Valencia, a zone not normally known for seismic activity, over the past month, according to Spain's National Geographic Institute.
The strongest, a 4.2 magnitude earthquake, hit in the early hours of Tuesday. It did not cause any damage but frightened residents.
Inmaculada Ramirez, a shop owner in the coastal town of Vinaros which faces the offshore gas storage plant, said she was woken up by the earthquake.
"The windows shook as if a train was flying overhead or a very long train was passing by," the 55-year-old told reporters.
There is some speculation this swarm was caused by the injection of gas into a giant offshore storage plant in the Gulf of Valencia. This certainly is plausible and also may have caused unintended consequences.
The plant is located near a fault line but the region has very little seismic activity, according to the president of Spain's College of Geologists, Luis Suarez. All activity has been halted until seismologist and geologist complete their investigation.
The Castor storage plant aims to store gas in a depleted oil reservoir 1.7 kilometers (1.05 miles) under the Mediterranean Sea and send it via a pipeline to Spain's national grid.
The plant, owned and operated by Spanish firm Escal UGS, can hold up to 1.3 billion cubic meters of gas, enough to meet the needs for the region of Valencia for three months.
The swarm has occurred over a mantle plume in the North Balearic Sea in the Valencia basin which is part of the Mediterranean basins.
The geological and geophysical characteristics of this realm indicate that extensional tectonics and mantle instability played a major role in the opening of the basin and consequent SE-directed drifting of its eastern flank (Balearic Rise).
A model for the generation of this basin is proposed, involving the intrusion of asthenospheric mantle and subsequent extensional detachment tectonics during late Oligocene-Miocene times. This model accounts for the asymmetrical rifting of the North Balearic Sea, and the clockwise drifting/rotation of the Balearic Rise.
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