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) (McClelland, L., ed.). Bulletin of the Global Volcanism Network, 16:7. Smithsonian Institution. https://doi.org/10.5479/si.GVP.BGVN199107-342030.
14.757°N, 91.552°W; summit elev. 3745 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 part of a chain of large stratovolcanoes that rise above the Pacific coastal plain of Guatemala. The sharp-topped, conical profile is cut on the SW flank by a 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 vents, with activity progressing W towards the most recent, 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.