Report on Fuego (Guatemala) — 6 June-12 June 2018
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 6 June-12 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, 6 June-12 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)
During 6-12 June INSIVUMEH and CONRED reported that strong 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. On 6 June lahars descended the Santa Teresa, Mineral, and Taniluyá drainages (tributaries of the Pantaleón river) and possibly the Honda drainage, halting search-and-rescue efforts. The lahars were 30-40 m wide, 2-5 m deep, and carried blocks (2-3 m in diameter) and tree parts. CONRED noted on 9 June that deposits on roads were being cleaned at a rate of 150 m per day, and that exposed deposits were as hot as 150 degrees Celsius. Significant hot lahars, 40 m wide and 5 m deep, traveled down the Seca, Mineral, Niágara, and Taniluyá drainages, carrying rocks and tree branches. On 10 June a strong lahar traveled down the Seca, Mineral, Niagara, Taniluyá, and Ceniza drainages. It was 35 m wide, 3 m deep, and carried blocks up to 1 m in diameter, tree trunks, and branches. Lahars that traveled down the Seca and Mineral drainages on 11 June were 40 m wide and 3 m deep. Lahars on 12 June were 20-45 m wide and 2-5 m deep, and flowed down the Ceniza and Mineral rivers.
During 6-11 June as many as nine weak explosions per hour produced ash plumes that rose as high as 1.1 km above the crater and drifted 8-15 km W, SW, and S. Avalanches of material descended the Las Lajas and Santa Teresa ravines. Some explosions vibrated local structures. At 0820 on 8 June a pyroclastic flow descended the Las Lajas and El Jute drainages, producing an ash plume that rose as high as 6 km and drifted W and SW. Explosive activity increased during 11-12 June, with dense ash plumes rising 1.3 km and drifting as far as 25 km N and NE. Pyroclastic flows traveled down the Seca drainage. According to CONRED, as of 12 June, the number of people that had died due to the 3 June pyroclastic flows was 110, and 197 more were missing. In addition, 12,578 people had been 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.