Geologic Background:
The small 3.5-km-wide island of Tinakula is the
exposed summit of a massive stratovolcano that rises 3-4
km from the sea floor at the NW end of the Santa Cruz
islands. Tinakula resembles Stromboli volcano in
containing a breached summit crater that extends from the
851-m-high summit to below sea level. Landslides enlarged
this scarp in 1965, creating an embayment on the NW
coast. The satellitic cone of Mendana is located on the
SE side. Tinakula has frequently been observed in
eruption since the era of Spanish exploration began in
1595. In about 1840, an explosive eruption apparently
produced pyroclastic flows that swept all sides of the
island, killing its inhabitants. Frequent historical
eruptions have originated from a cone constructed within
the large breached crater. These have left the upper
flanks of the volcano and the steep apron of lava flows
and volcaniclastic debris within the breach unvegetated.
Historic Activity:
- Tinakula's last reported eruption started Sept. 6,
1971, preceded by a small tsunami at the island.
Recent Activity:
- Eruption observed on June 3, 1984 on north side of
island. Active vent at the head of the landslide scarp on
the NW side of the volcano resulting from the 1971
landslide.
Data Sources:
- Smithsonian's SEAN Bulletin (V. 9, No. 6 and V. 10,
No. 6).
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