SATELLITES could pinpoint plentiful new sources of groundwater in arid
regions of the world by spotting the slight swelling of the Earth’s surface
caused by underground reservoirs.
Just as a sponge swells when it gets wet, the Earth’s crust can plump up when
underground aquifers fill with water. Now Wesley Danskin and Zhong Lu of the US
Geological Survey have shown that satellites can spot this swelling. At the
moment, water managers have to drill a series of wells to work out the size of
an aquifer. “One of the main advantages of this technique is you can see the…
