Report on Erta Ale (Ethiopia) — 26 January-1 February 2005
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 26 January-1 February 2005
Managing Editor: Gari Mayberry
Please cite this report as:
Global Volcanism Program, 2005. Report on Erta Ale (Ethiopia). In: Mayberry, G (ed.), Weekly Volcanic Activity Report, 26 January-1 February 2005. Smithsonian Institution and US Geological Survey.
13.6°N, 40.67°E; summit elev. 613 m
All times are local (unless otherwise noted)
An international team led by SVE, visited Erta Ale during 22-23 January. They observed no significant changes at the volcano since last observed in November 2004. Degassing continued from three of the four coalescent hornitos in the SW part of South Crater, but decreased slightly in comparison with observations made in December 2004. One hornito contained glowing molten lava. Degassing from North Crater also slightly decreased. Near the NW wall of the crater two small red glowing areas were visible at the summit of two hornitos in the crater.
Geologic Background. Erta Ale is an isolated basaltic shield that is the most active volcano in Ethiopia. The broad, 50-km-wide edifice rises more than 600 m from below sea level in the barren Danakil depression. Erta Ale is the namesake and most prominent feature of the Erta Ale Range. The volcano contains a 0.7 x 1.6 km, elliptical summit crater housing 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 is renowned for one, or sometimes two long-term lava lakes that have been active since at least 1967, or possibly since 1906. Recent fissure eruptions have occurred on the N flank.