Report on Fuego (Guatemala) — 16 May-22 May 2018
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 16 May-22 May 2018
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2018. Report on Fuego (Guatemala). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 16 May-22 May 2018. Smithsonian Institution and US Geological Survey.
14.473°N, 90.88°W; summit elev. 3763 m
All times are local (unless otherwise noted)
INSIVUMEH reported that beginning at 1400 on 17 May a lahar descended the Seca (Santa Teresa) drainage on Fuego’s W flank. The lahar was 25 m wide, 1 m deep, and carried trees and blocks 1.5 m in diameter. During 19-21 May explosions occurred at a rate of 5-8 per hour, and generated ash plumes that rose almost 1 km and drifted 10-20 km S, SW, and W. Some explosions were accompanied by rumbling audible more than 30 km away, and shock waves that vibrated structures in Morelia (9 km SW) and Panimaché (8 km SW). Incandescent material was ejected 200-300 m above the crater rim, and generated avalanches of material within the Seca, Ceniza (SSW), and Las Lajas (SE) drainages that reached vegetated areas. Ash fell in areas downwind including in Santa Sofía (12 km SW), Morelia, Panimaché I and II, and Finca Palo Verde. A lava flow 700-800 m long was active in the Ceniza drainage.
Geologic Background. Volcán Fuego, one of Central America's most active volcanoes, is one of three large stratovolcanoes overlooking Guatemala's former capital, Antigua. The scarp of an older edifice, Meseta, lies between 3763-m-high Fuego and its twin volcano to the north, Acatenango. 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 Acatenango. In contrast to 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.