The Sierra Nevada mountains grew nearly an inch taller during the recent drought and shrank by half an inch when water and snow returned to the area, according to new research from NASA’s Jet Propulsion Laboratory in La Cañada Flintridge.
They used the differences in height to estimate that 10.8 cubic miles of water were lost from the mountains between October 2011 and October 2015, enough to supply Los Angeles with water for 45 years.
“This suggests that the solid earth has a greater capacity to store water than previously thought,” said Donald Argus, a JPL research scientist.
Mountains give way slightly when snow, water and other precipitation accumulate on the surface, shrinking in height.
When the water is taken away, like during California’s recent drought, the mountains lose water weight, and grow.
As drought conditions sapped the Sierra of water between October 2011 and October 2015, the mountain range rose 24 millimeters, or nearly an inch.
Since October 2015, the Sierra has regained about half of the water lost during the drought and shrank a half-inch.
Scientists often think of aquifers as primarily layered, sedimentary rock, the type in which groundwater is stored, Famiglietti said.
The ability to estimate mountain water by observing changes in mountain elevations will help researchers better understand that.
“It’s an important problem in mountain hydrology, but it’s especially important in regions like California that need to account for every drop,” Famiglietti said.