According to unconfirmed reports from local authorities, Erta Ale began erupting on 24 September after a series of earthquakes occurred along the Afar western margin on the previous day. The earthquakes, with a maximum magnitude of 5.5, were recorded at the Geophysical Observatory of Addis Ababa University. A group of geologists and geophysicists were planning to travel to the field to make observations.

Geological Summary. The Erta Ale basaltic shield volcano is the most active in Ethiopia, with a 50-km-wide edifice that rises more than 600 m from below sea level in the barren Danakil depression. It is the namesake and most prominent feature of the Erta Ale Range. The volcano includes a 0.7 x 1.6 km elliptical summit crater hosting steep-sided pit craters. Another larger 1.8 x 3.1 km wide depression elongated parallel to the trend of the Erta Ale range is located SE of the summit and is bounded by curvilinear fault scarps on the SE side. Fresh-looking basaltic lava flows from these fissures have poured into the caldera and locally overflowed its rim. The summit caldera usually also holds at least one long-term lava lake that has been active since at least 1967, or possibly since 1906. Recent fissure eruptions have occurred on the N flank.

Source: Gezahegn Yirgu, Department of Earth Sciences, Addis Ababa University