Report on Santa Maria (Guatemala) — 23 July-29 July 2014

Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 23 July-29 July 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, 23 July-29 July 2014. Smithsonian Institution and US Geological Survey.

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Santa Maria

Guatemala

14.756°N, 91.552°W; summit elev. 3772 m

All times are local (unless otherwise noted)


INSIVUMEH reported that on most days during 23-29 July the active lava dome of Santiaguito was visibly degassing and generating plumes, noting an ash explosion on 26 July rising up to 3 km (9,800 ft) a.s.l. that drifted W. On 28 July thin ash columns rose 3.2 km (10,500 ft) a.s.l. that drifted SW. On most days, fumarolic columns reached 2.7-2.8 km (8,800-9,200 ft) a.s.l. that drifted SW and weak to strong avalanches flowed towards Canyon Nima River I.

Geologic Background. Symmetrical, forest-covered Santa MarĂ­a 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)