According to a news report, after a M 4.3 earthquake on 4 October an eruption occurred at Erta Ale. The earthquake occurred in the remote region of Afar and was the 11th earthquake in the region since September.

The following activity was incorrectly reported as occurring at Erta Ale when it actually occurred at Dabbahu. See the 12-18 October 2005 Weekly Volcanic Activity Report for the full report. A team of scientists visited the Da'Ure locality of Erta Ale on 4 and 5 October after there were reports of volcanic activity there on 26 September. They determined that a minor explosive eruption occurred from two semi-circular vents, producing ashfall that was ~5 cm thick near the vent and extended more than 500 m from the vent. Boulders ejected during the eruption were as large as 3 m and were deposited as far as 20 m away. The scientists noted intense degassing from the vents, the scent of sulfur dioxide, and the sound of boiling water in the vents.

Geological Summary. The Erta Ale basaltic shield volcano in Ethiopia has a 50-km-wide edifice that rises more than 600 m from below sea level in the Danakil depression. The volcano includes a 0.7 x 1.6 km 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. 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, and possibly since 1906. Recent fissure eruptions have occurred on the N flank.

Sources: Gezahegn Yirgu, Department of Earth Sciences, Addis Ababa University, Agence France-Presse (AFP)