Week 37 Volcano Watch

10 September-16 September 2008

New Activity/Unrest:

Bagana, Bougainville Island, Papua New Guinea

(September 16, 2008 ) Darwin VAAC analysis of satellite imagery revealed low-level ash plume from Bagana rising to an altitude of 2.4 km a.s.l., drifting SW.

More information and a Geologic Summary of Bagana

Bagana

Latitude: 6°8’24″S, Longitude: 155°11’42″E

Bagana volcano, occupying a remote portion of central Bougainville Island, is one of Melanesia’s youngest and most active volcanoes. Bagana is a massive symmetrical, roughly 1750-m-high lava cone largely constructed by an accumulation of viscous andesitic lava flows. The entire lava cone could have been constructed in about 300 years at its present rate of lava production. Eruptive activity at Bagana is frequent and is characterized by non-explosive effusion of viscous lava that maintains a small lava dome in the summit crater, although explosive activity occasionally producing pyroclastic flows also occurs. Lava flows form dramatic, freshly preserved tongue-shaped lobes up to 50-m-thick with prominent levees that descend the volcano’s flanks on all sides. (Image and caption: Global Volcanic Program. Image may be subject to copyright.)

Map of the Region. Credit: USGS

Ongoing Activity:

• Arenal, Costa Rica
• Chaitén, Southern Chile
• Dukono, Halmahera
• Galeras, Colombia
• Karymsky, Eastern Kamchat
• ka Kilauea, Hawaii (USA)
• Llaima, Central Chile
• Masaya, Nicaragua
• Piton de la Fournaise, Reunion Island
• Rabaul, New Britain
• Santa María, Guatemala
• Semeru, Eastern Java (Indonesia)
• Shiveluch, Central Kamchatka (Russia)
• Soufrière Hills, Montserrat
• Turrialba, Costa Rica
• Ubinas, Perú

The Weekly Volcanic Activity Report is a cooperative project between the Smithsonian’s Global Volcanism Program and the US Geological Survey’s Volcano Hazards Program.