Report on Barren Island (India) — 21 September-27 September 2005
Smithsonian / US Geological Survey Weekly Volcanic Activity Report,
21 September-27 September 2005
Managing Editor: Gari Mayberry
Please cite this report as:
Global Volcanism Program, 2005. Report on Barren Island (India). In: Mayberry, G (ed.), Weekly Volcanic Activity Report, 21 September-27 September 2005. Smithsonian Institution and US Geological Survey.
12.278°N, 93.858°E; summit elev. 354 m
All times are local (unless otherwise noted)
A pilot observed a plume emitted from Barren Island on 23 September around 1230 at a height of ~3 km (10,000 ft) a.s.l., extending ~90 km E. On 27 September, a low-level plume was visible on satellite imagery drifting NE. The current eruption of Barren Island began on 28 May 2005.
Geological Summary. 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.