Report on Santa Maria (Guatemala) — July 1991
Bulletin of the Global Volcanism Network, vol. 16, no. 7 (July 1991)
Managing Editor: Lindsay McClelland
Santa Maria (Guatemala) Explosions and avalanches; plumes to 600 m height
Please cite this report as:
Global Volcanism Program, 1991. Report on Santa Maria (Guatemala). In: McClelland, L (ed.), Bulletin of the Global Volcanism Network, 16:7. Smithsonian Institution. http://dx.doi.org/10.5479/si.GVP.BGVN199107-342030.
14.756°N, 91.552°W; summit elev. 3772 m
All times are local (unless otherwise noted)
The volcano was in a moderate explosive phase in May, emitting gray ash clouds 300-500 m high. In June, the number of moderate to strong explosions increased daily, with plumes 400-600 m high, and ashfall on the area surrounding the volcano. Numerous collapses and large avalanches were observed on the SE slope.
Geologic Background. Symmetrical, forest-covered Santa María volcano is one of the most prominent of a chain of large stratovolcanoes that rises dramatically above the Pacific coastal plain of Guatemala. The 3772-m-high stratovolcano has a sharp-topped, conical profile that is cut on the SW flank by a large, 1.5-km-wide crater. The oval-shaped crater extends from just below the summit to the lower flank and was formed during a catastrophic eruption in 1902. The renowned plinian eruption of 1902 that devastated much of SW Guatemala followed a long repose period after construction of the large basaltic-andesite stratovolcano. The massive dacitic Santiaguito lava-dome complex has been growing at the base of the 1902 crater since 1922. Compound dome growth at Santiaguito has occurred episodically from four westward-younging vents, the most recent of which is Caliente. Dome growth has been accompanied by almost continuous minor explosions, with periodic lava extrusion, larger explosions, pyroclastic flows, and lahars.
Information Contacts: Philippe Rocher, L.A.V.E., France.