Report on Deception Island (Antarctica) — September 1994
Bulletin of the Global Volcanism Network, vol. 19, no. 9 (September 1994)
Managing Editor: Edward Venzke.
Deception Island (Antarctica) Seismicity decreases; fumarole temperatures stable
Please cite this report as:
Global Volcanism Program, 1994. Report on Deception Island (Antarctica) (Venzke, E., ed.). Bulletin of the Global Volcanism Network, 19:9. Smithsonian Institution. https://doi.org/10.5479/si.GVP.BGVN199409-390030.
63.001°S, 60.652°W; summit elev. 602 m
All times are local (unless otherwise noted)
The Deception Volcano Observatory (figure 9) was created in 1993, but the volcano has been monitored every summer since 1986. Seismicity remained stable during the austral summer of 1993-94. The decrease in seismic activity seen during 1992-93 from 1991-92 levels continued. Only a few small local seismic events (M 1.5-2) and some larger events (M 2.5, >100 km depth) were detected. Fumaroles emitted mainly CO2 (94.7%) and H2S (3.5%); no SO2 was detected. Fumarole temperatures were similar to previous years near the Argentine Station (60.5°C), in Fumarole Bay (101.2°C), and at Steaming Hill (98.5°C).
Geologic Background. Ring-shaped Deception Island, one of Antarctica's most well known volcanoes, contains a 7-km-wide caldera flooded by the sea. Deception Island is located at the SW end of the Shetland Islands, NE of Graham Land Peninsula, and was constructed along the axis of the Bransfield Rift spreading center. A narrow passageway named Neptunes Bellows provides entrance to a natural harbor that was utilized as an Antarctic whaling station. Numerous vents located along ring fractures circling the low, 14-km-wide island have been active during historical time. Maars line the shores of 190-m-deep Port Foster, the caldera bay. Among the largest of these maars is 1-km-wide Whalers Bay, at the entrance to the harbor. Eruptions from Deception Island during the past 8700 years have been dated from ash layers in lake sediments on the Antarctic Peninsula and neighboring islands.
Information Contacts: C. Risso, Instituto Antártico Argentino; R. Ortiz, Museo Nacional de Ciencias Naturales, Spain.