Geologic Background:
Lokon-Empung is located on the north arm of
Sulawesi. The twin stratovolcanoes Lokum and Empung,
rising about 800 m above the plain of Tondano, are among
the most active volcanoes of Sulawesi. Lokon, the higher
of the two peaks, whose summits are only 2.2 km apart,
has a flat, craterless top. The morphologically younger
Empung volcano has a 400-m-wide, 150-m-deep crater that
erupted last in the 18th century, but all subsequent
eruptions have originated from Tompaluan, a 150 x 250 -
wide double crater situated in the saddle between the two
peaks.
Historic Activity:
- Eruptions in 1375, 1775, 1829, 1893, 1930 1942, 1949,
1951-1953, 1958-1959, 1965-1966, 1969-1971, 1973-1974,
1976-1977, and 1979.
Recent Activity:
- A small phreatic eruption on March 22, 1986 emptied
60% of the water from the small crater lake. On March 24,
1986 a larger phreatomagmatic eruption emptied the
remainder of the lake and ejected incandescent tephra.
Mudflows resulted from both eruptions. Small ash
eruptions have continued to occur with decreasing
frequency, with the last reported in April 1988.
- Ash explosions occurred several times during May and
September, 1991. Vigorous explosions on Oct. 24 ejected
ash to about 2 km height, and may have generated a
pyroclastic flow on Oct. 25. Other large explosions on
Nov. 17 & 20.
- Last reported explosion was on Dec. 11, 1991.
- Gas emmisions have continued since 1991.
- Lava fountains were reported in July and August 2000.
Low level activity continued for remainder of year.
- Explosion on Jan 28, 2001.
Data Sources:
- Smithsonian's SEAN Bulletin (V. 11, No. 3 to V. 13,
No. 4)
- Global Volcanism Network (V. 16, No. 5 to V. 26, No.
1).
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