Santa Maria, Guatemala

By ExploreNow Editor, on January 26th, 2012

Volcano Type:     Stratovolcano
Volcano Status:   Historical
Last Known Eruption:    2010 (continuing)
Summit Elevation:    3772 m    12,375 feet
Latitude:    14.756°N    14°45’21″N
Longitude:    91.552°W    91°33’6″W

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 of Volcán Santa María 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.

Santa Maria Volcano Eruption

Santiaguito is a dacitic lava dome complex which has been growing since 1922 in the crater left by the catastrophic 1902 eruption of Santa Maria volcano, Guatemala. Recent activity has involved small explosions, incandescent rockfalls, emission of block lava flows and dome inflation. Pyroclastic flows generated by collapses at lava flow fronts or resulting from dome collapses have also sporadically occurred. A major indirect impact of activity has been the frequent mobilization of loose volcanic material during the rainy season, which has resulted in numerous lahars (mudflows). These lahars have damaged infrastructure and settlements, notably El Palmar Viejo village 10km downstream of the volcano, which had to be abandoned in 1998. Lahar sediments, which may be many meters thick, can block rivers and change their courses. However, they are themselves easily eroded and massive erosion gulleys scar the landscape between Santiaguito and the pacific coast.