GEOLOGIC HISTORY
Gunung Marapi, not to be confused with the better-known
Merapi volcano on Java, is Sumatra's most active volcano.
Marapi is a massive complex stratovolcano that rises 2,000 m
above the Bukittinggi plain in Sumatra's Padang Highlands. A
broad summit contains multiple partially overlapping summit
craters constructed within the small 1.4-km-wide Bancah
caldera. The summit craters are located along an ENE-WSW
line, with volcanism migrating to the west.
Historic Activity:
- More than 50 eruptions, typically consisting of
small-to-moderate explosive activity, have been recorded
since the end of the 18th century; no lava flows outside
the summit craters have been reported in historical
time.
Recent Activity:
- In November 1984 several small plumes were observed
above the cone.
- In January 1987 a small explosion occurred. During
May through June 1987 several small explosions occurred
which resulted in ashfalls on two cities. During December
1987, many small explosions resulted in light ashfall
over western part of the island.
- Ash eruption around midnight on January 28-29, 1988.
Additional eruptions occurred on Feb. 19, 20, and 24;
March 1; and July 1 & 8.
- Marapi has been erupting since 1987, with explosions
typically occurring about once every 1 to 7 days.
Material ejected by the smaller explosions rises 100 to
800 m, whereas ejecta from larger explosions reach 800 to
2000 m above the summit. Series of strong explosions
began in June 1992 and continued into July 1992. An
eruption on Aug. 12, 1994 sent an ash column to Å6 km
altitude.
- Significant explosions in March 2000.
Data Sources
- Smithsonian's SEAN Bulletin (V. 3, No. 10 to V. 13,
No. 7)
- Global Volcanism Network (V. 17, No. 6 to V. 25, No.
9).
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