Overview
Erta Ale (or Ertale or Irta'ale; Amharic: ኤርታሌ) is a continuously active basaltic shield volcano in the Afar Region of northeastern Ethiopia, which is itself part of the wider Afar Triangle (a barren desert region straddling Djibouti, Ethiopia and Eritrea). Erta Ale is located in the Danakil Depression, an area below sea level between the last two countries, and is the most active volcano in Ethiopia.
Geology
Erta Ale is high, with one or sometimes two active lava lakes at the summit which occasionally overflow on the south side of the volcano. It is notable for holding the longest-existing lava lake, present since the early years of the twentieth century (1906). Volcanoes with lava lakes are very rare: there are only eight in the world.
Erta Ale means "smoking mountain" in the local Afar language and its southernmost pit is known locally as "the gateway to Hell". In 2009, it was mapped by a team from the BBC using three-dimensional laser techniques, in order for the mapping team to maintain a distance and avoid the lakes' searingly hot temperatures.
Erta Ale is centered over the East African Rift system, which is a triple junction setting whose movements are resulting in the formation of a pull-apart basin or rift. The volcano comprises mainly mafic material which has been brought up to the surface caused by unroofing of the mantle due to this rift formation.
From Wikipedia (CC BY-SA 4.0).