Report on Fuego (Guatemala) — 5 September-11 September 2012
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 5 September-11 September 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, 5 September-11 September 2012. Smithsonian Institution and US Geological Survey.
14.473°N, 90.88°W; summit elev. 3763 m
All times are local (unless otherwise noted)
In a special bulletin on 4 September at 1700, INSIVUMEH reported that the eruption from Fuego that began 32 hours earlier had ended. During 6-11 September fumarolic plumes rose 100-150 m above the crater and drifted W and NW. Weak explosions generated ash plumes that rose 300-400 m above the crater and drifted W and NW. During 8-9 September incandescent tephra was ejected to a height of 100 m and caused avalanches in the Taniluyá and the Ceniza (SSW) drainages. A 10-20-m-wide lahar traveled SE down the Las Lajas drainage on 9 September, carrying tree trunks and blocks 1.5 m in diameter. During 10-11 September a lava flow traveled 100 m down the Taniluyá drainage.
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.