Report on Barren Island (India) — 25 May-31 May 2005
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 25 May-31 May 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, 25 May-31 May 2005. Smithsonian Institution and US Geological Survey.
12.278°N, 93.858°E; summit elev. 354 m
All times are local (unless otherwise noted)
Professor Chandrasekharam, from the Indian Institute of Technology, reported that Indian Coast Guards noticed an eruption at Barren Island that began on the morning of 28 May. During the flank eruption on the NW side of the volcano's central cone, black lava was emitted that did not reach the sea. According to the Darwin VAAC, there were reports of a plume at a height below 3 km (10,000 ft) a.s.l. drifting N on 29 May at 1330.
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.