Geologic Background:
Erta Ale is an isolated basaltic shield volcano
that is the most active volcano in Ethiopia. The broad,
50-km-wide volcano rises 500 m from below sea level in
the barren Danakil depression. Erta Ale is one of the
most prominent features of and supplies its name to the
Erta Ale Range. It contains a 0.7 x 1.6 km, elliptical
summit crater housing steep-sided pit craters. One, or
sometimes two lava lakes have been active since at least
1967, or possibly since 1906. Another larger depression
is located to the SE of the summit. Recent fissure
eruptions have occurred on the northern flank.
Historic Activity:
- Probable eruptions in about 1873 and1904. Confirmed
eruptions in 1906, and 1960.
Recent Activity:
- Lava lakes have been present in 2 craters since 1967,
and possibly since 1906.
- Difficult access (civil war) has prevented fieldwork
since 1976.
- Landsat Thematic Mapper data showed both lava lakes
to have cool (<400°C) crusts and some
incandescent cracks (1150°C) in January 1986.
- A lava fountain estimated at 1-2 m high was observed
in one vent during an overflight on Sept. 21, 1992.
Active lava lakes were visited during decent into crater
on Nov. 10-11, 1992.
- Active lava lakes were observed on Dec.6-11,
1995.
Data Sources:
- Smithsonian's SEAN Bulletin (V. 12, No. 8 and V. 12,
No. 12)
- Global Volcanism Network (V. 17, No. 8 to V. 20, No.
12).
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