Report on Santa Maria (Guatemala) — 14 January-20 January 2004

Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 14 January-20 January 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, 14 January-20 January 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)


On the morning of 15 January a moderate explosion at Santa Maria's Santiguito lava-dome complex caused a collapse at the edge of the crater. Volcanic material traveled down the volcano's SW flank, reaching the base. Ash rose ~900 m above the crater and fell on the observatory and property near the volcano. Weak avalanches occurred in the SE portion of the lava dome. On 19 January moderate explosions occurred and avalanches descended the lava dome. The plumes produced from the explosions traveled E, depositing small amounts of fine ash around the volcano, including on the ranches of San Jose, Quina, and San Juan Patzulín.

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.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH), Washington Volcanic Ash Advisory Center (VAAC)