Danakil Depression, Ethiopia
October 23, 2007
The photo above shows the arid Danakil Depression (a lava lake of the former Erta Ale volcano) in the East African Rift Zone of Ethiopia, where at 120 m (394 ft) below mean sea level numerous mineral springs are evident. Here, water is recycled through almost 900 m (2,952 ft) of saline deposits. In the hot dry air, this water readily evaporates, leaving deposits of white halite (common salt) and green melanterite (hydrated iron sulfate), which becomes yellow and orange when oxidized (as copiapite). Potash, gypsum and borax deposits are also present. In the background, the small cones build by the springs measure just 50 to 80 cm (20 to 32 in). Photo taken on February 16, 2007.