Smithsonian Institution
Global Volcanism Network Bulletin v. 20, no. 1, January 1995

Aoba (Vanuatu)  Volcanic seismicity felt during 1-7 December

Aoba (Ambae)
Ambae Island, Vanuatu
15.40 S, 167.83 E; summit elev. 1,496 m

Unusual seismicity was felt by island residents during 1-7 December
1994, with a maximum of 7 small-to-medium events on the 5th. These
volcanic events were of high-frequency and lacked individualized
phases. At the suggestion of ORSTOM, the National Disaster
Management Office organized a helicopter reconnaissance on 7
December to inspect the volcano for evidence of possible eruptive
activity. Activity at the Lake Vui crater and the fumarolic area on
the shore of Lake Manoro was similar to that observed during
previous aerial observations on 24 July 1991 and September 1993.
Small areas of hot and gaseous water were evident at Lake Vui, and
the rainforest was completely burned around the crater. No large
bubbles like those noted in July 1991 (10 m in diameter) were
observed (Bulletin v. 16, no. 7). An automated seismic alert
station, with satellite transmission to Port Vila, will be
installed near Lake Vui.

Aoba, also known as Ambae, is a broad basaltic shield volcano with
pronounced NE-SW rift zones that give the island an elongated form.
A broad pyroclastic cone containing a crater lake is located at the
summit within the younger of two nested calderas, the largest of
which is 6 km in diameter. The last known eruption, around 1870,
produced lahars that destroyed villages on the SE flank. According
to local legends, an eruption around 1670 caused many fatalities on
the NW coast.

Information Contact: Michel Monzier, Institut Francais de Recherche
Scientifique pour le Developpement en Cooperation (ORSTOM) and
Vanuatu Dept of Geology, Mines & Water Resources, BP 76, Port Vila,