Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92093, USA.
Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92093, USA. United States Geological Survey, La Jolla, CA 92093, USA.
Science. 2014 Sep 26;345(6204):1587-90. doi: 10.1126/science.1260279. Epub 2014 Aug 21.
The western United States has been experiencing severe drought since 2013. The solid earth response to the accompanying loss of surface and near-surface water mass should be a broad region of uplift. We use seasonally adjusted time series from continuously operating global positioning system stations to measure this uplift, which we invert to estimate mass loss. The median uplift is 5 millimeters (mm), with values up to 15 mm in California's mountains. The associated pattern of mass loss, ranging up to 50 centimeters (cm) of water equivalent, is consistent with observed decreases in precipitation and streamflow. We estimate the total deficit to be ~240 gigatons, equivalent to a 10-cm layer of water over the entire region, or the annual mass loss from the Greenland Ice Sheet.
自 2013 年以来，美国西部一直经历着严重的干旱。伴随着地表及近地表水体的大量流失，固体地球的响应应该是大范围的抬升。我们利用连续运行的全球定位系统站的季节性调整时间序列来测量这种抬升，并对其进行反演以估算质量损失。抬升的中位数为 5 毫米（mm），在加利福尼亚山脉中，数值高达 15mm。由此推断出的质量损失模式，范围可达 50 厘米（cm）的水当量，与观测到的降水和径流量减少相一致。我们估计总亏缺量约为 2400 亿吨，相当于整个地区覆盖一层 10 厘米厚的水，或格陵兰冰原的年质量损失。
