Report on Mahawu (Indonesia) — August 1994
Bulletin of the Global Volcanism Network, vol. 19, no. 8 (August 1994)
Managing Editor: Richard Wunderman.
Mahawu (Indonesia) Mudpots, small geysers, and vigorous, noisy fumaroles
Please cite this report as:
Global Volcanism Program, 1994. Report on Mahawu (Indonesia). In: Wunderman, R. (ed.), Bulletin of the Global Volcanism Network, 19:8. Smithsonian Institution. https://doi.org/10.5479/si.GVP.BGVN199408-266110.
1.352°N, 124.865°E; summit elev. 1299 m
All times are local (unless otherwise noted)
Part of the EVS report follows. "During our observations at 1100 on 9 July intense and noisy gas emissions (like a jet engine) occurred near the low NW part of the inner wall of the crater. These gas emissions generated a gray-white plume. This area of the crater was covered by many yellow sulfur deposits. A strong smell of hydrogen sulfide was also noted. An important solfatara zone surrounded the NW, N, NE, and E sides of the green, ~40,000 m3, acidic crater lake. Two small geysers, the one in the N and the other in the NW, were very active (2-3 m height). Several boiling basins and mud pots were active around the lake. It was not possible to get down into the crater without rock climbing equipment, because the crater walls were very steep." EVS observers also proposed that a low part of the S wall had collapsed.
Geologic Background. The elongated Mahawu volcano immediately east of Lokon-Empung volcano is the northernmost of a series of young volcanoes along a SSW-NNE line near the margin of the Quaternary Tondano caldera. Mahawu is capped by a 180-m-wide, 140-m-deep crater that sometimes contains a small crater lake, and has two pyroclastic cones on its N flank. Historical activity has been restricted to occasional small explosive eruptions recorded since 1789. In 1994 fumaroles, mudpots, and small geysers were observed along the shores of a greenish-colored crater lake.
Information Contacts: H. Gaudru, C. Pittet, M. Auber, C. Bopp, and O. Saudan, EVS, Switzerland.