Based on analyses of satellite imagery, the Washington VAAC reported that on 2 February an ash plume from Santa María's Santiaguito lava dome complex drifted less than 30 km SW and quickly dissipated. INSIVUMEH reported that during 2-3 February explosions produced ash plumes that rose 300 m above Caliente dome and drifted S and SW. On 4 February the VAAC noted that an ash plume was detected in satellite imagery. INSIVUMEH notices also stated that fumarolic plumes rose as high as 150 m above the dome during 2-3 and 6-7 February and drifted SE and W. Several landslides on the flanks occurred during 6-7 February. Explosions during 7-8 February produced ash plumes that rose 400 m above the dome and drifted SE.

Geological Summary. Symmetrical, forest-covered Santa María volcano is part of a chain of large stratovolcanoes that rise above the Pacific coastal plain of Guatemala. The sharp-topped, conical profile is cut on the SW flank by a 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 vents, with activity progressing E towards the most recent, 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)