Scientists are now reporting that earthquakes from mini to major can occur with water being injected or extracted from the ground.

The most recent discovery was that farmers in the Lorca area of Spain continued to drill deeper and deeper wells in past decades in order to continue pumping water to grow fruits and vegetables as well as water livestock.

Frank Jordan with the Associated Press wrote about the cause of the 5.1 magnitude quake that killed nine and injured almost 300 people that hit the town of Lorca on May 11, 2011. The report was that the water table dropped about 274 yards in 50 years with the continued well digging and high water use. 

Other incidents similar to the Lorca one have been reported in the world, and the scientists that studied the Lorca quake were from Spain, Italy and Canada. The incident of water tables going through major drops is common in some Mediterranean areas.

The European water table drops are not unlike the drops occurring with some U.S. aquifers. How low do aquifers have to go before unsettling the earth for some degree of quake being caused in the U.S.?

It is not only extraction of water but other human activities that could trigger earthquakes, most of them quite small. “Earlier this year, a report by the National Research Council in the United States found the controversial practice of hydraulic fracturing to extract natural gas was not a huge source of man-made earthquakes. However, the related practice of shooting large amounts of wastewater from ‘fracking’ or other drilling activities into deep underground storage wells has been linked with some small earthquakes,” Jordan wrote for the AP.

Some scientists say all these incidents point to the need to investigate more closely how quakes might be triggered by human activity and how to prevent them.