Report on Santa Maria (Guatemala) — February 1989
Scientific Event Alert Network Bulletin, vol. 14, no. 2 (February 1989)
Managing Editor: Lindsay McClelland.
Santa Maria (Guatemala) Increased explosive activity; possible new lava flow
Please cite this report as:
Global Volcanism Program, 1989. Report on Santa Maria (Guatemala). In: McClelland, L. (ed.), Scientific Event Alert Network Bulletin, 14:2. Smithsonian Institution. https://doi.org/10.5479/si.GVP.SEAN198902-342030.
14.757°N, 91.552°W; summit elev. 3745 m
All times are local (unless otherwise noted)
Increased explosive activity began in late February. Seismic records showed about six explosions/day through most of February, but a distinct increase was observed beginning 24 February [but see 14:06], reaching 20/day by 28 February. On 3 March, geologists climbing Fuego, roughly 75 km ESE, saw several vigorous ash emissions/hour from Santiaguito. Ash fell on Quezaltenango, 12 km NE, and Zuñil, 10 km ENE. Residents of the area suspect that a new lava flow may have formed [see 14:06]. Glow was observed from the previously active Caliente and El Brujo vent areas during the night of 12-13 March.
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: INSIVUMEH; Michael Doukas and John Ewert, USGS.