GPS Tracks Dwindling Water Supply in West

 GPS stations monitoring minute movements within the Earth’s crust used for collecting earthquake-related data are also collecting data on the serious drought affecting the western states.

Using the GPS data, geophysicists from the Scripps Institution of Oceanography estimate the overall loss of water is around 240 billion metric tons, or roughly a 4-inch layer of water covering the space from the Rocky mountains to the Pacific ocean, according to a recent report in Science magazine.

The weight of water indents the Earth’s crust and when the water is gone, the crust rebounds–therefore allowing the GPS stations to accurately measure the amount of water that’s disappeared.