Logo link to homepage

Report on Rabaul (Papua New Guinea) — 9 January-15 January 2008


Smithsonian Institution / US Geological Survey
Weekly Volcanic Activity Report, 9 January-15 January 2008
Managing Editor: Sally Sennert.

Please cite this report as:

Global Volcanism Program, 2008. Report on Rabaul (Papua New Guinea) (Sennert, S, ed.). Weekly Volcanic Activity Report, 9 January-15 January 2008. Smithsonian Institution and US Geological Survey.

Weekly Report (9 January-15 January 2008)


Papua New Guinea

4.271°S, 152.203°E; summit elev. 688 m

All times are local (unless otherwise noted)

RVO reported that intermittent ash and vapor plumes from Rabaul caldera's Tavurvur cone were observed during 8-15 January. On 11 January, a small explosion produced an ash plume that rose to altitudes of 1.2-1.5 km (3,900-4,900 ft) a.s.l. and drifted SE. During 11-15 January, ash and vapor plumes rose to altitudes of 0.9-1.2 km (3,000-3,900 ft) a.s.l. and drifted SE, E, NE, N, and W. Slight ashfall was reported about 20 km SE in Tokua on 11 and 12 January. Data from deformation-monitoring instruments indicated no deformation. Incandescence from the lava dome on the crater floor was occasionally visible at night.

Geological Summary. The low-lying Rabaul caldera on the tip of the Gazelle Peninsula at the NE end of New Britain forms a broad sheltered harbor utilized by what was the island's largest city prior to a major eruption in 1994. The outer flanks of the asymmetrical shield volcano are formed by thick pyroclastic-flow deposits. The 8 x 14 km caldera is widely breached on the east, where its floor is flooded by Blanche Bay and was formed about 1,400 years ago. An earlier caldera-forming eruption about 7,100 years ago is thought to have originated from Tavui caldera, offshore to the north. Three small stratovolcanoes lie outside the N and NE caldera rims. Post-caldera eruptions built basaltic-to-dacitic pyroclastic cones on the caldera floor near the NE and W caldera walls. Several of these, including Vulcan cone, which was formed during a large eruption in 1878, have produced major explosive activity during historical time. A powerful explosive eruption in 1994 occurred simultaneously from Vulcan and Tavurvur volcanoes and forced the temporary abandonment of Rabaul city.

Source: Rabaul Volcano Observatory (RVO)