Geologic Background:
Batur volcano, about 80 km NE of Denpasar,
Bali's capital, and 18 km NW of Agung volcano, is located
at the center of two concentric calderas NW of Agung
volcano. A caldera lake is present on the SE side of the
larger 10 x 13 km caldera. The inner 7.5-km-wide caldera
was formed about 23,670 years ago during emplacement of
the Bali ignimbrite. The SE wall of the inner caldera
lies beneath Lake Batur. The caldera contains an active,
700-m-tall stratovolcano rising above the surface of Lake
Batur.
Historic Activity:
- Batur has been frequently active (at least 21
eruptions) since its first historic eruption in
1804.
- Historical eruptions have been characterized by
mild-to-moderate explosive activity sometimes accompanied
by lava emission.
- Basaltic lava flows from both summit and flank vents
have reached the caldera floor and the shores of Lake
Batur in historical times
Recent Activity:
- Batur's most recent reported eruption, in March-April
1974, produced lava flows and numerous ash
ejections.
- An eruption on Aug. 7, 1994 from the east part of the
summit, Batur Crater III, caused ashfall as far as Å6 km
WSW. Incandescent lava fragments and black smoke were
ejected to heights of 300 m. Eruption ended on Aug.
11.
- New eruption began in March 1999 and activity has
continued into September 2000. Typically small explosions
and ash emissions.
- Minor activity in March and April 2001.
Data Sources:
- Smithsonian's SEAN Bulletin (V. 14, No. 11)
- Global Volcanism Network (V. 19, No. 7 and V. 26, No.
9)
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