INSIVUMEH reported that strong explosions at Caliente cone, part of Santa María's Santiaguito lava-dome complex, began at 1023 on 7 February and generated rumbling sounds and shock waves detected as far as 25 km away. Pyroclastic flows descended the E and SE flanks. A dense mushroom-shaped ash cloud obscured the E, SW, and S parts of the volcano, and then rose 6 km above the crater. It drifted in multiple directions NW to SW. During 8-9 February white gas plumes rose 300 m above the lava dome and drifted E and SW.

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.

Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH)