On 22 March INSIVUMEH reported that activity at Fuego had increased during the previous few days. There were 15-20 explosions per hour producing ash plumes that rose as high as 1.3 km above the summit and drifted 20-30 km E, SE, S, SW, and W. Ashfall was reported in communities downwind including La Rochela, Ceylán, San Andrés Osuna, Las Palmas, Siquinalá, and Santa Lucia Cotzumalguapa (23 km SW). Shock waves vibrated residential structures within 20 km. The explosions also caused avalanches of material from the crater that traveled down the Seca (W), Ceniza (SSW), Taniluyá (SW), Trinidad (S), Las Lajas (SE), and Honda ravines. In the evening on 21 March and early morning hours of 22 March lava fountains rose 350 m above the summit.

During 23-26 March explosions occurred at a rate of 15-25 per hour, generating ash plumes that rose as high as 1.2 km and drifted 15-20 km W, S, and SE. Explosions sometimes vibrated nearby residences. Incandescent material was ejected 200-300 m high and caused avalanches of material that traveled down Seca, Taniluyá, Ceniza, Trinidad, Las Lajas, and Honda ravines, sometimes reaching vegetated areas. Ashfall as reported in areas downwind including Panimache I (8 km SW), Morelia (8 km SW), Santa Sofia (12 km SE), La Rochela, and San Andrés Osuna.

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)