Report on Santa Maria (Guatemala) — 6 August-12 August 2014
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 6 August-12 August 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, 6 August-12 August 2014. Smithsonian Institution and US Geological Survey.
14.756°N, 91.552°W; summit elev. 3772 m
All times are local (unless otherwise noted)
On 6-12 August, INSIVUMEH reported fumarolic columns rose to 2.7-2.8 km (8,800-9,200 ft) a.s.l. above Santiaguito to the S, SW and W. On most days, the lava flow (2.3 km in length) moved towards and into Nima Canyon I. Collapse avalanches from the flow front generated columns of fine ash that rose 100-200 m above the flow front drifting E. On 9 August ash was reported on the southeast of Finca San José On the evening of 11-12 August INSIVUMEH reported incandescence at the crater.
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.