Report on Heard (Australia) — 7 June-13 June 2006
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 7 June-13 June 2006
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2006. Report on Heard (Australia). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 7 June-13 June 2006. Smithsonian Institution and US Geological Survey.
53.106°S, 73.513°E; summit elev. 2745 m
All times are local (unless otherwise noted)
From 11 March to 2 June, MODVOLC (a MODIS thermal alert system) detected approximately 10 alerts from or near the summit of Big Ben on Heard Island. The area of the thermal anomaly was 1 to 2 pixels in size (1 pixel=1 km).
Geologic Background. Heard Island on the Kerguelen Plateau in the southern Indian Ocean consists primarily of the emergent portion of two volcanic structures. The large glacier-covered composite basaltic-to-trachytic cone of Big Ben comprises most of the island, and the smaller Mt. Dixon lies at the NW tip of the island across a narrow isthmus. Little is known about the structure of Big Ben because of its extensive ice cover. The historically active Mawson Peak forms the island's high point and lies within a 5-6 km wide caldera breached to the SW side of Big Ben. Small satellitic scoria cones are mostly located on the northern coast. Several subglacial eruptions have been reported at this isolated volcano, but observations are infrequent and additional activity may have occurred.