Report on Santa Maria (Guatemala) — 9 November-15 November 2005
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 9 November-15 November 2005
Managing Editor: Gari Mayberry
Please cite this report as:
Global Volcanism Program, 2005. Report on Santa Maria (Guatemala). In: Mayberry, G (ed.), Weekly Volcanic Activity Report, 9 November-15 November 2005. Smithsonian Institution and US Geological Survey.
14.757°N, 91.552°W; summit elev. 3745 m
All times are local (unless otherwise noted)
During 11-14 November, several explosions occurred at Santa María's Santiaguito lava-dome complex, producing ash plumes to a height of 1.2 km above the volcano (or 16,300 ft a.s.l.). Several small pyroclastic flows traveled down the SW, NE, and S flanks of Caliente dome. Frequent avalanches of volcanic material occurred off of the fronts of active lava flows mostly to the W of Caliente dome, and less frequently to the S and NE. An ash-and-gas emission on 14 November produced a cloud that was visible on satellite imagery.
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 stratovolcano has a sharp-topped, conical profile that 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 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.