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. http://dx.doi.org/10.5479/si.GVP.SEAN198902-342030.
14.756°N, 91.552°W; summit elev. 3772 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 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: INSIVUMEH; Michael Doukas and John Ewert, USGS.