INSIVUMEH reported that eruptive activity continued at Fuego during 20-26 March. Explosions were recorded daily, averaging 3-12 per hour each day. The explosions generated ash and gas plumes that rose as high as 1 km above the crater rim and drifted as far as 30 km in multiple directions; ballistics occasionally fell as far as 2 km away. Frequent block avalanches caused by the explosions descended various drainages, including the Ceniza (SSW), Seca (W), Taniluyá (SW), Santa Teresa (W), and Las Lajas (SE), and sometimes reached vegetated areas. Incandescent material was ejected 100-300 m above the summit on 22 and 24 March. Weak rumbling sounds and shock waves were frequently reported. On 21 March ashfall was reported in Panimache (8 km SW), Morelia (9 km SW), and Santa Sofía (12 km SW).

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)