Report on Fuego (Guatemala) — 4 July-10 July 2012
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 4 July-10 July 2012
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2012. Report on Fuego (Guatemala). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 4 July-10 July 2012. 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 during 4-6 July explosions from Fuego produced ash plumes that rose 400-800 m above the crater and drifted W. Rumbling sounds were reported and tephra avalanches descended the S flank. During 7-8 July rumbling and degassing sounds were reported. Although cloud cover mostly prevented observations, a weak plume was noted rising 200-300 m above the crater and drifting NE. Ash fell in Yepocapa (8 km WNW), and on the La Conchita and Monteclaro ranches. Small tephra avalanchas descended the Taniluyá (SW) and Ceniza (SSW) drainages. During 8-9 July a series of seven explosions produced ash plumes that rose 300-900 m above the crater and drifted 10 km W, again causing ashfall in Yepocapa, La Conchita, Monte llano, and Sangre de Cristo (8 km WSW). Explosions on 10 July produced ash plumes that rose 300-600 m above the crater and drifted W. Incandescence rose above the crater during 8-10 July.
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.