Report on Bristol Island (United Kingdom) — 4 May-10 May 2016
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 4 May-10 May 2016
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2016. Report on Bristol Island (United Kingdom). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 4 May-10 May 2016. Smithsonian Institution and US Geological Survey.
59.017°S, 26.533°W; summit elev. 1100 m
All times are local (unless otherwise noted)
Based on analysis of satellite images, an eruption at Bristol Island likely began on 24 April, the first eruption since 1956. Landsat images detected a plume and a thermal anomaly in the main crater at the top of Mt. Sourabaya. By 1 May the anomaly was elongated to the W, suggesting that lava had breached the crater rim.
Geologic Background. The 9 x 10 km Bristol Island near the southern end of the South Sandwich arc lies across Fortser's Passage from the Southern Thule Islands and forms one of the largest islands of the chain. Largely glacier-covered, it contains a horseshoe-shaped ridge at the interior extending northward from the highest peak, 1100-m-high Mount Darnley. A steep-sided flank cone or lava dome, Havfruen Peak, is located on the east side, and a young crater and fissure are on the west flank. Three large sea stacks lying off Turmoil Point at the western tip of the island may be remnants of an older now-eroded volcanic center. Both summit and flank vents have been active during historical time. The latest eruption, during 1956, originated from the west-flank crater, and deposited cinder over the icecap. The extensive icecap and the difficulty of landing make it the least explored of the South Sandwich Islands.
Source: Matthew Patrick, US Geological Survey - Hawaiian Volcano Observatory