Human activities are believed to have played a major role in last year’s deadly earthquake in Spain. According to Pablo Gonzalaz of the University of Western Ontario, the author of a study published in the journal Nature Geoscience, the drop in the water level of a reservoir pressured the Earth’s surface causing the deadly quake that took the lives of nine people.
To test that theory, they used satellite data to see how the terrain was deformed by the earthquake, and found that it correlated to changes in the Earth’s crust caused by a 273-yard (250-metre) drop in the natural groundwater level over the last five decades due to groundwater extraction. Their findings suggest that human-induced stress on faults like the one near Lorca, known as the Alhama de Murcia Fault, can not only cause an earthquake but also influence how far the fault will slip as a result.
The quake’s epicenter was the Spanish town of Lorca. Gonzalez told Reuters: “We cannot set up a rule just by studying a single particular case, but the evidence that we have collected in this study could be necessary to expand research in other future events that occur near … dams, aquifers and melting glaciers, where you have tectonic faults close to these sources.”