SAN DIEGO – In the wake of Sunday’s 6.0-magnitude earthquake in Napa Valley, scientists are now questioning whether or not there is a connection between earthquakes and the drought.
A study earlier this year in the journal Nature found that a lack of water in the San Joaquin Valley is decreasing the weight on the San Andreas Fault, which could lead to more earthquakes.
“Much of this would be smaller earthquakes but theoretically you could get a larger quake,” said Adrian Borsa with the Scripps Institution of Oceanography.
Since July, 80 percent of California has been in severe drought, and as a result the ground level is shifting, scientists said. With less water in the aquifer beneath it to hold it up the soil throughout the Central Valley is sinking.
The study suggests that while the Central Valley is sinking, the surrounding mountain ranges are climbing.
“The uplift is due to the fact that the earth is elastically responding to the water-load being lifted. It’s rising up the same way as if you had a rubber block and you were pressing down on it and now released the pressure,” said Borsa.
The pressure, once occupied by heavy ground water, is now largely gone, according to reports.
Since 2013, 63 trillion gallons of water have depleted form the western part of the United States due to the drought.
Uplift not contributed from pumping has caused the ground level to lift up to a sixth of an inch and nearly half an inch in the mountain areas, according to Borsa.
Borsa believes that this type of uplift isn’t enough to trigger a large-scale earthquake.
“Stressing on the earth from this uplift is just not that significant,” said Borsa.