INSIVUMEH reported that by 8 October the lava flows on Fuego’s flanks were 800 m and 1.5 km long, and advancing into the Santa Teresa (W) and Trinidad (S) drainages, respectively. Ash plumes from explosions rose 750 m above the crater and drifted 12 km W and SW. Ashfall was reported in Morelia, Sangre de Cristo, Panimache, and Santa Sofía. On 10 October at 2100 activity became constant; incandescent material was ejected 200 m high. Strombolian activity during 12-13 October continued to feed lava flows on the flanks; flows had advanced to 1 and 1.3 km away from the crater in the Santa Teresa and Trinidad drainages, respectively. Explosions, some producing shock waves, continued to generate ash plumes that rose as high as 750 m above the crater and drifted 12 km SW. Ashfall was again reported in Morelia, Sangre de Cristo, Panimache, and Santa Sofía.

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)