The drought in the western areas of the United States is having yet another impact on the region, this one totally unexpected, researchers say; the entire zone is rising up like an uncoiling spring.
GPS stations across the region have yielded confirmation of the uplift, with parts of California's mountains being pushed upward by as much as half an inch as the large-scale loss of groundwater continues.
A similar lift of around 0.15 inches has been recorded throughout the rest of the region, scientists from the Scripps Institution of Oceanography at the University of California, San Diego report.
The uplift is the result of a water deficit of some 62 trillion gallons, an amount that would cover the entire western United States to a depth of 6 inches, they say.
The rise recorded by the GPS sensors is evidence of a rapid uplift of the tectonic plate on which the western half of the United States sits, they explain.
In the period from 2003 to this year, all of the GPS stations of the Plate Boundary Observatory of the National Science Foundation moved upwards during the extended phase of the current ongoing drought, Scripps geophysicist Adrian Borsa says.
For the researchers, the effects are more evidence of the worrying hydrological crisis in the region.
"These results quantify the amount of water mass lost in the past few years," says Dan Cayan a meteorologist with both Scripps and the U.S. Geological Survey. "It also represents a powerful new way to track water resources over a very large landscape."
In California, 99.8 percent of the state remains in "severe" drought, the third harshest on a five-level scale used by the U.S. Drought Monitor center at the University of Nebraska-Lincoln.
The network of sensors allows the researchers to estimate resources in the Sierra Nevada Mountains and gauge the vital California snowpack as a water source, they said.
The findings could be applied to other areas of the world where knowledge of water supplies are critical, they said.
"These results demonstrate that this technique can be used to study changes in fresh water stocks in other regions around the world, if they have a network of GPS sensors," Cayan says.
Answering concerns about possible seismic risk posed by the widespread uplifting, the researchers said it would have no effect on California's San Andreas Fault and would not result in an elevated risk of earthquakes.
The study, supported by the USGS, has been published in the online edition of the journal Science.