A hidden trove of groundwater is left over from the last ice age.
Aside from the Nile River’s green corridor, much of northeastern Africa is desert. But the arid landscape hides a secret: Vast quantities of groundwater fill an underground aquifer that spans four countries.
A new study using chloride isotopes to date the groundwater under Egypt’s Eastern Desert has found that the water in smaller, shallower aquifers is refilled by the larger, deeper aquifer, where vast quantities of groundwater date to the last ice age. Read more.