Two pyroclastic flows were also detected. Ashfall was reported in multiple areas downwind. Based on analyses of satellite imagery, the Washington VAAC reported that ash was detected on March. 6 The next day an ash plume drifted almost 20 km SouthWest.
During March 7 - 8 the seismic network detected explosions, avalanches, and pyroclastic flows. At least eight pyroclastic flows descended the flank and deposited material in Rio Nima II. Ash plumes rose 1 km causing ashfall in areas downwind.
Symmetrical, forest-covered Santa María volcano is one of a chain of large stratovolcanoes that rises dramatically above the Pacific coastal plain of Guatemala. The stratovolcano has a sharp-topped, conical profile that is cut on the SW flank by a large, 1-km-wide crater, which formed during a catastrophic eruption in 1902 and extends from just below the summit to the lower flank. The renowned Plinian eruption of 1902 followed a long repose period and devastated much of SW Guatemala. The large 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, accompanied by almost continuous minor explosions and periodic lava extrusion, larger explosions, pyroclastic flows, and lahars. (GVP)