Report on Fuego (Guatemala) — 10 February-16 February 2021
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 10 February-16 February 2021
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2021. Report on Fuego (Guatemala). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 10 February-16 February 2021. 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 continuous avalanches of material at Fuego during 9-10 February descended the Ceniza (SSW), Seca (W), Trinidad (S), Taniluyá (SW), Las Lajas (SE), and Honda drainages. There were 8-12 explosions per hour, generating ash plumes that rose as high as 1.1 km above the crater rim that drifted 15-20 km W and SE. Ashfall was reported in areas downwind including Santa Sofía, Panimache, Morelia, and Yucales, and shockwaves were audible up to 15 km away. The number of explosions increased to 3-6 per hour during 11-12 February. Ash-and-gas plumes rose to 1.1 km and drifted W and SW, causing ashfall in Sangre de Cristo, Palo Verde, and Yepocapa. Shock waves were felt by nearby residents. Avalanches of material descended the flanks, reaching vegetated areas.
During 12-13 February incandescent material was ejected 200 m above the summit and shock waved vibrated local structures. A lava flow had traveled 1 km down the Ceniza drainage, spalling blocks from the flow front that reached vegetated areas. By 14 February the lava flow had lengthened to 1.5 km and a lava flow in the Seca drainage traveled 500 m. During 1020-1023 a series of pyroclastic flows traveled several hundred meters down the Ceniza. Ash plumes from explosions rose 850 m and drifted NE, E, and SE, and caused ashfall in Alotenango, El Porvenir, and Finca La Reunion, in the department of Sacatépequez. During 14-15 February explosions ejected incandescent material 100 m above the summit and rattled nearby structures. Ash plumes rose as high as 450 m and drifted short distances E. Lava flows remained active; they were 800 and 200 m long in the Ceniza and Seca drainages, respectively. Block avalanches from the lava-flow fronts reached vegetated areas.
The lava effusion rate had steadily decreased during the late morning of 15 February. During the afternoon explosions, occurring at a rate of 14-30 per hour, produced ash plumes that rose 850-1,050 m above the summit and drifted as far as 50 km E, NE, and N. Ash fell in Porvenir and Alotenango. Activity continued to decrease through the day, characterized by a reduction in the explosion rate, less intense summit incandescence, and low RSAM values. INSIVUMEH declared an end to the effusive eruption phase. Explosions (12-14 per hour) generated ash plumes that rose over 1 km and drifted 130 km N, NE, and E.
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.