Report on Fuego (Guatemala) — 8 August-14 August 2007
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 8 August-14 August 2007
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2007. Report on Fuego (Guatemala). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 8 August-14 August 2007. 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 on 8 August, a Strombolian eruption of Fuego produced gas-and-ash plumes that rose to altitudes of 4.8-5.6 km (15,700-18,400 ft) a.s.l. and drifted W and SW. Lava flows advanced and avalanches of incandescent blocks traveled down river valleys, including the Ceniza river valley to the SW. Several pyroclastic flows descended the flanks and ashfall was reported in villages to the W, SW, and S. CONRED raised the Alert Level to Orange (level 3 on a scale of 1-4) in surrounding communities on 8 August, based on a later report from INSIVUMEH.
On 9 August, there was a substantial decrease in vigor of the Strombolian eruption. Explosions produced plumes to altitudes of 4.4-4.8 km (14,400-15,700 ft) a.s.l. and drifted SW. A lava flow traveled 1.5 km SW down the Ceniza river valley and landslides of incandescent blocks were observed. INSIVUMEH issued a report later that day stating that the activity had further decreased to normal levels. A few explosions produced plumes to an altitude of 4.3 km (14,100 ft) a.s.l. and drifted SW.
On 10 August, CONRED decreased the Alert Level to Yellow. INSIVUMEH reported that the lava flows that were active during 8-9 August were no longer visible. On 10 and 13 August, small explosions produced plumes to an altitude of 4.3 km (14,100 ft) a.s.l. and drifted SW.
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.