Sink (geography)

In geography a sink is an area of dry land below sea-level, for example the Salton Sink and the Afar Depression.

Sinks tend to occur in arid areas where evaporation exceeds rainfall and the sea cannot enter.

In the past
Sinks are the cause of some of the big natural salt deposits, formed by water flowing in and evaporating.

The biggest and deepest sink that is known to have existed was the dry bed of the Mediteranean Sea in the Messinian salinity crisis in the late Miocene period.

Other big former sinks are
 * The Gulf of Mexico in the Mesozoic as the Atlantic Ocean was starting to form as Pangaea started to break up.
 * The Red Sea in parts of the Cenozoic when the Perim Island volcano blocked the Bab el Mandeb.