NASA Study Finds Sierra Nevada Rise And Fall Based On Rainfall Years

SACRAMENTO (CBS13) — A study released on Wednesday by NASA used GPS from satellites to measure how much the Sierra Nevada Mountains rose and fell during drought years and wet water years.

The study showed that during the drought years of October 2011 to October 2015 the mountains rose about 1 inch, or 24 mm, and fell about 0.5 inches, or 12 mm, the two following wet years. This is due to the Earth's surface falling locally when it is weighed down by water storage during wet years and rising from the lack of water weight.

When compared to hydrological models, this suggests that the solid Earth has a greater capacity to store water than previously thought. Before the study, it was thought that extensive groundwater pumping and tectonic plate movement played a bigger part in the rise and fall of the Sierra Nevada mountains.

NASA says they believe they can use the estimates of water change from GPS to inform water managers how much water they will be getting in the springtime from the snowpack, but not everyone is convinced.

Dr. Jay Lund from UC Davis says this gives us a better idea over a widespread area of water content but doesn't give us the localized numbers we may need to be able to make more informed water management decisions. We may not be completely there yet, but this study is showing that the technology is starting to head that way.