A new study published in Science by the Scripp’s Institution of Oceanography at UC San Diego found that the earth’s crust is slowly rising in the West “like an uncoiled spring” due extreme drought. Scripps researchers found that the water shortage is causing an “uplift” effect of up to half and inch in California’s mountains, and 0.15 of an inch on average across the West.
The drought-related uplifting was discovered when researchers analyzed data from GPS stations within the National Science Foundation’s Plate Boundary Observatory. One researcher noticed that all of the GPS stations moved upward since 2003, coinciding with the timing of the current drought. Klaus Jacob, a seismologist at Columbia University’s Lamont-Doherty Earth Observatory in Palisades, New York tells us that groundwater weighs down the Earth. And when you take that load away (in this case because of the drought), the Earth’s crust decompresses and the surface rises. And from the amount it rises, you can estimate the water deficit. Most of the movement occurred since last year as the West’s drought has become more and more extreme, said study co-author Duncan Agnew, a professor at the Institute of Geophysics and Planetary Physics at Scripps.
Agnew says that the uplifting likely has no significant effect on earthquake potential in California and elsewhere – even though loss of ground and surface water has added stress to major faults in the region. “The total amount of stress that’s been added in the last 18 months from drought is the same amount of stress that’s added every week because of plate techtonics,” he said. Jacob said the study shows that the changes in the elevation of the landscape and the stress on faults are so small the effect will be extremely minor. The significance of the study is really that it shows a new way for scientists to estimate total water loss during times of drought.
Via Climate Central
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