A study of California’s Sierra Nevada during the state’s extreme drought has led NASA scientists to new conclusions about how our planet stores water.
The study by NASA’s Jet Propulsion Laboratory in Pasadena, California, found that the mountain range rose nearly 2.5 centimeters in height from October 2011 to October 2015, when the state experienced its most extended drought.
In the following two years, with abundant snow and rain, the range lost about half, or 1.3 centimeters, of its new height.
“This suggests that the solid Earth has a greater capacity to store water than previously thought,” study leader Donald Argus said in a statement released Wednesday.
“One of the major unknowns in mountain hydrology is what happens below the soil. How much snowmelt percolates through fractured rock straight downward into the core of the mountain?” said Jay Famiglietti, a Jet Propulsion Lab scientist who participated in the research. “This is one of the key topics that we addressed in our study.”
The scientists reasoned that the Earth’s surface sinks when it is weighed down with water and rebounds when the water evaporates or is otherwise lost.
The study used data from 1,300 Global Positioning System stations in the mountains of California, Oregon and Washington that were placed for measurement of subtle tectonic motion in active faults and volcanoes and can detect elevation changes of less than 0.3 centimeter.
The scientists determined that the water lost in the four-year drought was about 45 times the amount that Los Angeles uses in a year.
The study also took into account other reasons for the change in height of the mountain range that runs 644 kilometers along California’s border with Nevada, including tectonic uplift or the extensive pumping of groundwater during the drought.