Report on Santa Maria (Guatemala) — 15 March-21 March 2023
Smithsonian Institution / US Geological Survey
Weekly Volcanic Activity Report, 15 March-21 March 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, 15 March-21 March 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 Santa Maria-Santiaguito lava dome complex remained highly active during 15-21 March. Emissions of gas and steam rose up to 800 m above the crater and drifted S, SW, and SE. Almost daily explosions produced ash plumes that rose as high as 800 m above the summit and often drifted SW. Effusion from Caliente dome fed lava flows that slowly descended the San Isidro and Zanjón Seco drainages on the W and SW flanks. Incandescence from the dome during the nights and early mornings. Block-and-ash flows originated from Caliente, and the middle and front of the lava flow. Lahars descended the Cabello de Ángel drainage (a tributary of Nimá I on the SE flank) on 19 March and consisted of a cement-like mixture of volcanic material, branches, and tree trunks.
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.