Severe drought in the western United States is leading to much worse consequences than it appears on the surface. The drought in recent years is changing the landscape, browning the lawns, and pushing up the food prices. Using GPS technology, scientists estimated the water deficit at a whopping 63 trillion gallons. That’s enough to spread out a four-inch layer of water over the entire western U.S.
Drought causes earth surface to rise up to 15mm
The study was conducted by scientists at the Scripps Institution of Oceanography of the University of California, San Diego, and was supported by the U.S. Geological Survey (USGS). Findings of the research appeared in August 21 issue of the journal Science. What shocked everyone was that the broad-scale loss of water has caused the earth level in the entire western U.S. to rise “like an uncoiled spring.”
Scientists Adrian Borsa, Dan Cayan and Duncan Agnew investigated the ground positioning data from GPS stations. They found that the drought has caused an “uplift” of up to 15mm (more than half an inch) in the mountains of California. On average, the earth level has risen four millimeters across the western U.S. While going through various data sets, geophysicist Borsa observed the same pattern over the 2013-14 period. All the GPS stations had moved upward, coinciding with the current drought.
Why does drought cause earth level to rise?
Researchers said the tectonic plate on which the western U.S. rests had seen rapid uplifting. Results of the stud represent a new way to track water resources across a large landscape. Why does the earth level rises during severe drought? Borsa said water found in lakes, rivers, and underground reservoirs acts as ballast for the earth, weighting it down. When water evaporates naturally or removed by humans, but not replaced by snowmelt or rain, a heavy weight has been taken off the land’s shoulders. That’s why it lifts up.
A study conducted by NASA revealed last month that the drought was a major threat to the regional water supply and underground water resources. It’s the worst drought in the region since 2002.