Report on Santa Maria (Guatemala) — 1 February-7 February 2023
Smithsonian Institution / US Geological Survey
Weekly Volcanic Activity Report, 1 February-7 February 2023
Managing Editor: Sally Sennert.
Please cite this report as:
Global Volcanism Program, 2023. Report on Santa Maria (Guatemala) (Sennert, S, ed.). Weekly Volcanic Activity Report, 1 February-7 February 2023. Smithsonian Institution and US Geological Survey.
14.757°N, 91.552°W; summit elev. 3745 m
All times are local (unless otherwise noted)
INSIVUMEH reported that the eruption at Santa María’s Santiaguito lava-dome complex continued during 31 January-6 February. Effusion from Caliente cone fed lava flows that descended the San Isidro and Zanjón Seco drainages on the W and SW flanks; the longest part of the lava flow was 4.4 km on 15 January. Incandescence from the dome and the lava flows was visible nightly. Block-and-ash flows from the dome, and from both the ends and sides of the flows, descended the S, SW, and W flanks almost daily. “Curtains” of ash sometimes rose several hundred meters along their paths. Explosions were generally weak-to-moderate in size and produced gas-and-steam plumes with minor amounts of ash that rose several hundred meters above the complex. Explosions and accompanying rumbling were heard in El Palmar (12 km SSW) during 3-4 February. Ashfall from both explosions and block-and-ash flows was reported in the Monte Claro (S), El Faro, and La Florida (6 km S), Santa Marta, and El Viejo Palmar (11 km S) ranches during 3-4 February.
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 W 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.