Spanish farmers' ever-deeper wells blamed for earthquake
Study finds ever-deeper extraction of water probably caused deadly Spanish quake, but others say it would have occurred anyway
Farmers drilling ever deeper wells over decades to water their crops probably contributed to a deadly earthquake in southern Spain last year, a new study suggests. The findings may add to concerns about the effects of new technologies for energy extraction and waste disposal.
Nine people died and nearly 300 were injured when an unusually shallow magnitude-5.1 quake hit the town of Lorca on May 11.
Using satellite images, scientists from Canada, Italy and Spain found the quake ruptured a fault running near a basin that had been weakened by 50 years of groundwater extraction.
During this period, the water table fell 250 metres as farmers bored ever deeper wells to help produce the fruit, vegetables and meat exported from Lorca to the rest of Europe. In other words, the industry that propped up the local economy in southern Spain may have undermined the very ground on which Lorca is built.
The researchers noted that even without the strain caused by water extraction, a quake would probably have occurred at some point. But the extra stress of pumping vast amounts of water from a nearby aquifer may have been enough to trigger a quake at that particular time and place, said lead researcher Pablo Gonzalez of the University of Western Ontario, Canada.
A geologist with Spain's National Natural Science Museum who has worked on the same theory but was not involved in the study, Miguel de las Doblas Lavigne, said the Lorca quake was in the cards.