Dallol is a cone volcano in the Danakil Depression, northeast of the Erta Ale Range in Ethiopia. It has been formed by the intrusion of basaltic magma into salt deposits and subsequent hydro thermal activity. Eruptions took place in 1926, forming Dallol Volcano. Numerous other eruption craters dot the salt flats nearby. These craters are the lowest known sub aerial volcanic vents in the world, at 45 m (150 ft) or more below sea level. In October 2004 the shallow magma chamber beneath Dallol deflated and fed a magma intrusion southwards beneath the rift. Numerous hot springs are discharging brine and acidic liquid here. Small, widespread, temporary geysers produce cones of salt.
The term Dallol was coined by the Afar people and means dissolution or disintegration, describing a landscape of green acid ponds and iron oxide, sulfur and salt desert plains. The area resembles the hot springs areas of Yellowstone Park but it is much hotter and its waters are much more acidic.
info source: wikipedia