GEOLOGIC HISTORY
Deception Island's flooded caldera forms a 5 x 9
km bay with its mouth to the SW, thus giving the island
an open ring shape.
Historic Activity:
- Eruptions in 1812, 1829, 1839, 1842, 1871, 1909,
1912, 1927, 1955, 1967, 1969, and 1970.
- The last documented eruption of Deception Island, in
1970, was more violent than its predecessors in 1967 and
1969. Five maar-like submarine craters and 7 land vents
along an arcuate zone about 5 km long erupted tephra and
built about 1.5 sq. km of new land in the Telefon Bay
area.
Recent Activity:
- Seismic data suggested that an eruption occurred in
September. Seismicity in 1987 and 1988 but no reported
eruption. A plume on satellite imagery was observed in
July 1987. Neither the 1972 or 1987-1988 activity could
be confirmed by ground observations.
- Increased seismic activity during 1991-1992 survey.
- Decreased seismic activity during 1992-1993 survey.
- Decreased seismic activity during 1993-1994 survey.
- Decreased seismic activity during 1996-1997
survey.
- Moderate seismic activity in 2001.
Data Sources
- Smithsonian's SEAN Bulletin (V. 12, No. 8 to V. 14,
No. 3)
- Global Volcanism Network (V. 15, No. 3 to V. 26 , No.
5).
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