Erta Ale is a shield volcano, located in the Afar depression at 13.6°N, 40.67°E, 613 m (location map).
It is part of the East African rift system. It has a base diameter of 30 km and is only 500 m high. In its vast summit caldera
(1600x700 m) there are two pit craters. The larger one (300-400 m diameter) in the northern part contained a lava lake in 1968 and
1973 but is now inactive. A central, but smaller pit (140 m diameter, 60 to 90 m deep) now has an active lava lake 60 m wide
and 100 m long (cross section, drawing by P. Vetsch).
Summit caldera of Erta Ale (1600x700 m) from NW (lava lake in smaller pit).
Aerial view of the active pit (diameter about 140 m).
Western caldera rim, looking S to shield volcano Hayli Gub (also part of Erta Ale volcanic range).
The active pit from the edge with the lava lake in its western half.
The basaltic lava lake (about 60x100 m) from the edge of the pit.
Note bench mark above present lake level. No variation of the level was observed.
Early morning, from the edge of the active pit (moon upper right).
Lava lake at night from edge of pit.
Descending into the pit crater.
When the fountaining was not too strong, it was possible to approach the lake to within a few meters.
Temperatures in the pit were similar to the outside. Gases were removed by convection above the lake.
Small fountaining (about 5 to 6 meters) at night
|Copyright: Before using pictures from STROMBOLI ON-LINE on other WWW servers or publishing any of them in printed form please contact J. Alean or P. Vetsch. The photos below were taken (and are ©) by P. Vetsch in 1995 (PV), G. Favre, Geologos in 1995 (GF) and by L. Cantamessa, Geodecouverte SA in 1992 (LC).|