Report on Fuego (Guatemala) — 20 May-26 May 2020
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 20 May-26 May 2020
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2020. Report on Fuego (Guatemala). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 20 May-26 May 2020. 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 in the evening on 20 May a new lava flow at Fuego traveled 300 m down the Ceniza (SSW) drainage. The crater was incandescent and gas emissions were constant; avalanches descended the flanks 1 km and reached vegetated areas. Explosions produced shock waves and ash plumes that rose just over 1 km above the summit. Lahars descended the Las Lajas ravine on the E flank 1650 on 21 May and the Ceniza drainage on the SW flank.
There were 5-12 explosions per hour recorded during 22-26 May, generating ash plumes as high as 1.1 km above the crater rim that generally drifted 10-15 km in multiple directions. Shock waves rattled buildings within a 20-km radius, particularly in areas on the S flank. Incandescent material was ejected 100-300 m high and caused avalanches of blocks in the Ceniza, Seca (W), Trinidad (S), Las Lajas, and Honda drainages. Ashfall was reported in several areas downwind including Santa Sofía (12 km SW), Morelia (9 km SW), Panimaché I and II (8 km SW), Ciudad Vieja (13.5 km NE), San Miguel Dueñas (10 km NE), and Antigua Guatemala (18 km NE). Lava flows in the Ceniza drainage varied in length between 150 and 400 m long.
Geologic Background. 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.