Report on Santa Maria (Guatemala) — 24 March-30 March 2004

Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 24 March-30 March 2004
Managing Editor: Gari Mayberry

Please cite this report as:

Global Volcanism Program, 2004. Report on Santa Maria (Guatemala). In: Mayberry, G (ed.), Weekly Volcanic Activity Report, 24 March-30 March 2004. Smithsonian Institution and US Geological Survey.

Volcano Profile |  Complete Weekly Report |  Download PDF [future] |  Export Citation [future]


Santa Maria

Guatemala

14.757°N, 91.552°W; summit elev. 3745 m

All times are local (unless otherwise noted)


Weak to moderate explosions at Santa María's Santiaguito lava dome produced plumes up to 1 km above the vent. Light ashfall occurred in nearby areas on several occasions during the reporting period. On 25 March incandescent avalanches derived from the S flank of the Caliente dome flowed to the SE along various routes. Lahars descended the Nimá I river on 28 March and the Nimá I and Nimá II rivers on the evening of 29 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.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)