Report on Barren Island (India) — 13 July-19 July 2005
Smithsonian / US Geological Survey Weekly Volcanic Activity Report,
13 July-19 July 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, 13 July-19 July 2005. Smithsonian Institution and US Geological Survey.
12.278°N, 93.858°E; summit elev. 354 m
All times are local (unless otherwise noted)
According to a pilot's report, ash was visible near Barren Island on 18 July at 0211 at a height of ~6.1 km (~20,000 ft) a.s.l. Ash was observed on satellite imagery on 18 July at 0755 below a height of 4.6 km (15,100 ft) a.s.l.
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.