Report on Seulawah Agam (Indonesia) — 13 July-19 July 2011
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 13 July-19 July 2011
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2011. Report on Seulawah Agam (Indonesia). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 13 July-19 July 2011. Smithsonian Institution and US Geological Survey.
5.448°N, 95.658°E; summit elev. 1810 m
All times are local (unless otherwise noted)
CVGHM reported that during October 2010-July 2011 activity at Seulawah Agam decreased. Measurements indicated that seismicity decreased, water temperature decreased and pH levels were stable, gas emissions were lower, and no significant surface changes were observed. The Alert Level was lowered to 1 (on a scale of 1-4) on 11 July.
Geologic Background. Seulawah Agam at the NW tip of Sumatra is an extensively forested volcano of Pleistocene-Holocene age constructed within the large Pleistocene Lam Teuba caldera. A smaller 8 x 6 km caldera lies within Lam Teuba caldera. The summit contains a forested, 400-m-wide crater. The active van Heutsz crater, located at 650 m on the NNE flank of Suelawah Agam, is one of several areas containing active fumarole fields. Sapper (1927) and the Catalog of Active Volcanoes of the World (CAVW) reported an explosive eruption in the early 16th century, and the CAVW also listed an eruption from the van Heutsz crater in 1839. Rock et al. (1982) found no evidence for historical eruptions. However the Volcanological Survey of Indonesia noted that although no historical eruptions have occurred from the main cone, the reported NNE-flank explosive activity may have been hydrothermal and not have involved new magmatic activity.