Report on Fuego (Guatemala) — 20 June-26 June 2018
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 20 June-26 June 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, 20 June-26 June 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 and CONRED reported that during 20-26 June multiple lahars at Fuego were often hot, steaming, and had a sulfur odor, and were generated from heavy rains and the recent accumulation of pyroclastic-flow deposits from the 3 June events. Lahars remained a significant hazard, and descended the Cenizas (SSW), Las Lajas (SE), Santa Teresa (W), and Taniluyá (SW) drainages. They were 25-45 m wide, as deep as 3 m, and often carried blocks up to 3 m in diameter, tree trunks, and branches. The agencies warned that because the Las Lajas drainage is full of deposits, lahars can continue to descend that drainage or create new channels in San Miguel Los Lotes (one of the hardest-hit areas).
Explosions continued, producing ash plumes that rose as high as 1.3 km above the crater and drifted as far as 15 km in multiple directions. Ashfall was reported in Panimache, Morelia, Sangre de Cristo, and finca Palo Verde on 22 June. Avalanches of material descended the SE, S, and W flanks (Santa Teresa, Las Lajas, and Cenizas drainages). According to CONRED, as of 26 June, the number of people confirmed to have died due to the 3 June pyroclastic flows was 112, and 197 more were missing. In addition, 12,823 remained evacuated.
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.