Report on Fuego (Guatemala) — 14 August-20 August 2002
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 14 August-20 August 2002
Managing Editor: Gari Mayberry
Please cite this report as:
Global Volcanism Program, 2002. Report on Fuego (Guatemala). In: Mayberry, G (ed.), Weekly Volcanic Activity Report, 14 August-20 August 2002. Smithsonian Institution and US Geological Survey.
14.473°N, 90.88°W; summit elev. 3763 m
All times are local (unless otherwise noted)
A new cycle of eruptive activity began at Fuego on 16 July that consisted of an increase in Strombolian explosions and the occurrence of high-frequency volcanic tremor for 24 hours. On 28 July a thick gray ash cloud extended 10-15 km in length and drifted to the W. Ash was deposited in the areas of Rochela, Panimaché, Morelia, Santa Sofía, Yepocàpa, and Chimaltenango. This activity was associated with the collapse of the front of a lava flow, which began on 23 January. On 29 July an increase in seismic activity was recorded, the energy of explosions in the crater increased, and there was a 2- to 3-km-long lava flow. On 2 August explosions changed from Strombolian to Vulcanian, ash columns rose 800-1,400 m above the crater, and avalanches of volcanic blocks traveled down the volcano's flanks. The same day, gas emission from the crater decreased significantly, and the SE lava flow did not travel as quickly as it had previously.
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.