Mountains Rising Due To Groundwater Pumping

If the significance of California's water needs were not already clear, it now appears that the thirst of the state is literally moving mountains.

"The Sierra Nevada Mountains are getting higher, and they are being pushed by human activity," Capital Public Radio recently reported, citing a new article published in the journal Nature. "Geologists are testing to see if the trends increase as people pump more water to cope with drought."

Researchers already knew that the mountains were rising. “We first wrote two years ago about the rapid rise of the Sierra, with its 14,000-foot peaks in the south and 10,000-foot peaks at Lake Tahoe moving as much as 1 to 3 millimeters per year,” said Geoff Blewitt, one of the researchers, in the Tahoe Daily Tribune.

The new research adds another piece to the puzzle. "The results of our earlier research cannot be explained easily by geology alone. We've now found that a reason for the rapid uplift may be linked to human activity," he added, in a release from the University of Nevada.

The mountain ranges have risen about 6 inches over the last century-and-a-half. "Winter rains and summer groundwater pumping in California's Central Valley make the Sierra Nevada and Coast Mountain Ranges sink and rise by a few millimeters each year," the National Science Foundation announced in a release, citing a the Nature article.

It appears human activity plays an indispensable role. "Gradual depletion of the Central Valley aquifer, because of groundwater pumping, raises these mountain ranges by a similar amount each year--about the thickness of a dime," the Foundation said.

Still not impressed? It appears the stresses could lead to earthquakes. “The stress is very small, much less than you need to build up stress on a fault leading to an earthquake, but in some circumstances such small stress changes can be the straw that breaks the camel’s back,” Roland Bürgmann, one of the researchers, said to the San Francisco Chronicle. “It could just give that extra push to get a fault to fail.”

http://www.wateronline.com/doc/mountains-rising-due-to-groundwater-pumping-0001