INSIVUMEH reported increased activity at Fuego on 1 June, characterized by an increase in the number of explosions (6-7 per hour) and ash plumes rising as high as 950 m above the crater and drifting W. Explosions generated shock waves that rattled structures in multiple areas including Panimaché I and II (8 km SW), Morelia (9 km SW), Santa Sofía (12 km SW), El Porvenir, and Sangre de Cristo (8 km WSW). Incandescent material was ejected as high as 500 m above the crater rim, and caused avalanches of material on the flanks. On 2 June explosions produced ash plumes that rose 550-950 m and drifted 10-12 km W and SW. Shock waves were detected within a radius of 25 km. Incandescent material was ejected 300-500 m high, causing avalanches in the Ceniza (SSW), Taniluyá (SW), and Santa Teresa (W) drainages. During 3-4 June there were 2-4 explosions recorded per hour. Ash plumes rose 650-1,050 m high and drifted 8-10 km W and SW. Weak shock waves rattled nearby buildings. Avalanches from ejected incandescent material continued to descend the three drainages. On 4 June a hot lahar descended the Pantaleón (W) drainage, carrying blocks more than 2 m in diameter, branches, and tree trunks. The lahar was 30 m wide and had a strong sulfur odor. During 4-5 June incandescent material rose 150 m and a lava flow traveled 300 m down the Santa Teresa drainage. On 6 June INSIVUMEH noted that eruptive episode number five had ended, with remnant lava flows in the Santa Teresa (2 km long) and Ceniza (3 km long) drainage. Explosions generated ash plumes that rose 950 m and drifted 15 km W and NW.

Geological Summary. Volcán Fuego, one of Central America's most active volcanoes, is also one of three large stratovolcanoes overlooking Guatemala's former capital, Antigua. The scarp of an older edifice, Meseta, lies between Fuego and Acatenango to the north. Construction of Meseta dates back to about 230,000 years and continued until the late Pleistocene or early Holocene. Collapse of Meseta may have produced the massive Escuintla debris-avalanche deposit, which extends about 50 km onto the Pacific coastal plain. Growth of the modern Fuego volcano followed, continuing the southward migration of volcanism that began at the mostly andesitic Acatenango. Eruptions at Fuego have become more mafic with time, and most historical activity has produced basaltic rocks. Frequent vigorous historical eruptions have been recorded since the onset of the Spanish era in 1524, and have produced major ashfalls, along with occasional pyroclastic flows and lava flows.

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