Spanish earthquake which killed nine and injured hundreds 'was triggered by extraction of groundwater'
- The magnitude 5.1 tremor struck historic town of Lorca in May 2011
- Despite being 1,000 times smaller than 9.0 earthquake in Japan, the historic city was was left devastated by the disaster
- Research suggests earthquake was caused by extraction of groundwater
- Findings could have wider implications for the extraction of shale gas
A major earthquake in Spain that killed nine people and injured more than a hundred was man-made following the extraction of groundwater, say scientists.
The magnitude 5.1 tremor struck the historic town of Lorca in south-east Spain last May.
Despite being 1,000 times smaller than the devastating 9.0 earthquake that struck Japan and triggered a tsunami a few months earlier in March 2011, the Lorca earthquake caused lives to be lost, reduced buildings to large piles of rubble and left cars flattened.
Devastated: A policewoman consoled the daughter of a victim (pictured middle) following the Lorca earthquake in May 2011, which claimed nine lives.
Now scientists say they have found evidence the disaster was man-made and believe it was the result of water being sucked out of the ground to feed domestic supplies.
The loss of the water caused stress changes in the earth's crust along a major faultline, triggering a rupture in the rock and leading to the earthquake, according to the research.
The findings, published in the journal Nature Geoscience, highlight the extent to which human activity can influence seismic shocks.
Scientists led by Dr Pablo Gonzalez, from the University of Western Ontario in Canada, used satellite data to map the ground deformation caused by the Lorca earthquake.
They then carried out computer simulations of the fault slip. The results showed a pattern that correlated with stress changes due to loss of groundwater.
Since the 1960s, natural groundwater levels in the region have reduced by 250 metres.
Cause of the quake: Scientists believe water extraction may have resulted in the earthquake that devastated Lorca last May.
The researchers wrote: 'We conclude the presented data and modelling results are consistent with a groundwater crustal unloading process, providing a reasonable explanation for the observed fault slip pattern.'
The findings implied that 'anthropogenic activities could influence how and when earthquakes occur'.
In an accompanying commentary article, Professor Jean-Philippe Avouac, from the California Institute of Technology in Pasadena, US, wrote: 'We should remain cautious of human-induced stress
perturbations. We know how to start earthquakes, but we are still far from being able to keep them under control.'
Crushed: A car stands destroyed by debris following the 5.1 tremor.
Collapse: Historic buildings were reduced to rubble, destroyed cars in Lorca in May 2011.
Professor Peter Styles, from Keele University, said the findings could have wider implications for extracting shale gas, which uses hydraulic fracturing or 'fracking' as it is commonly known.
He said: 'This is a very exciting and stimulating paper. The authors comment on the role which anthropogenic activity can play in stimulating the response of the crust and there will no doubt be speculation as to the implications of this for hydraulic fracturing in the context of shale gas exploration.'
Evacuation: Residents fled for their lives following the disaster, which may have been man-made, according to new research.
Damaged: Birds fly over the cracked bell tower of the church in Lorca, following the tremor which claimed the largest number of earthquake-related deaths in Spain for more than 50 years.