Report on Santa Maria (Guatemala) — 12 February-18 February 2014
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 12 February-18 February 2014
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2014. Report on Santa Maria (Guatemala). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 12 February-18 February 2014. Smithsonian Institution and US Geological Survey.
14.757°N, 91.552°W; summit elev. 3745 m
All times are local (unless otherwise noted)
In a special bulletin on 11 February, INSIVUMEH noted that activity at Santa María's Santiaguito lava-dome complex had increased in recent days. Explosions from Caliente dome were accompanied by block avalanches and pyroclastic flows that traveled NE. Ash plumes rose 3.5 km and drifted over 15 km S and SW. Some explosions were audible in areas as far as15 km S. During 13-14 February explosions generated ash plumes that rose no more than 200 m above the crater. During 16-17 February the E part of the lava dome was incandescent and lava flows descended the E and W flanks. Gas plumes from Caliente dome rose 300 m.
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.