Report on Barren Island (India) — 12 March-18 March 2003
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 12 March-18 March 2003
Managing Editor: Gari Mayberry
Please cite this report as:
Global Volcanism Program, 2003. Report on Barren Island (India). In: Mayberry, G (ed.), Weekly Volcanic Activity Report, 12 March-18 March 2003. Smithsonian Institution and US Geological Survey.
12.278°N, 93.858°E; summit elev. 354 m
All times are local (unless otherwise noted)
A team of scientists from India and Italy who visited Barren Island during 3-6 February found fumaroles on parts of the volcano's SW cone that reached temperatures up to 101°C. Neither magma nor gas emissions were observed in any of the various cones. The ground temperature was relatively high (40°C) from the middle to the upper part of the western cone and steaming ground was clearly visible at many sites. Several steam vents were visible within the 1995 lava flows. Blue fumes, which are indicative of the presence of SO2, and the smell of acidic gases were not recorded.
Geologic Background. Barren Island, a possession of India in the Andaman Sea about 135 km NE of Port Blair in the Andaman Islands, is the only historically active volcano along the N-S volcanic arc extending between Sumatra and Burma (Myanmar). It is the emergent summit of a volcano that rises from a depth of about 2250 m. The small, uninhabited 3-km-wide island contains a roughly 2-km-wide caldera with walls 250-350 m high. The caldera, which is open to the sea on the west, was created during a major explosive eruption in the late Pleistocene that produced pyroclastic-flow and -surge deposits. Historical eruptions have changed the morphology of the pyroclastic cone in the center of the caldera, and lava flows that fill much of the caldera floor have reached the sea along the western coast.