Report on Nevado del Huila (Colombia) — 22 July-28 July 2009
Smithsonian Institution / US Geological Survey
Weekly Volcanic Activity Report, 22 July-28 July 2009
Managing Editor: Sally Sennert.
Please cite this report as:
Global Volcanism Program, 2009. Report on Nevado del Huila (Colombia) (Sennert, S, ed.). Weekly Volcanic Activity Report, 22 July-28 July 2009. Smithsonian Institution and US Geological Survey.
Nevado del Huila
2.93°N, 76.03°W; summit elev. 5364 m
All times are local (unless otherwise noted)
INGEOMINAS reported that during 22-28 July four pulses of seismic tremor from Nevado del Huila indicated explosions. Gas plumes were seen on a web camera and during a commercial flight. On 23 July, ashfall was reported in an area to the NW. The Alert Level remained at III (Yellow; "changes in the behavior of volcanic activity").
Geological Summary. Nevado del Huila, the highest peak in the Colombian Andes, is an elongated N-S-trending volcanic chain mantled by a glacier icecap. The andesitic-dacitic volcano was constructed within a 10-km-wide caldera. Volcanism at Nevado del Huila has produced six volcanic cones whose ages in general migrated from south to north. The high point of the complex is Pico Central. Two glacier-free lava domes lie at the southern end of the volcanic complex. The first historical activity was an explosive eruption in the mid-16th century. Long-term, persistent steam columns had risen from Pico Central prior to the next eruption in 2007, when explosive activity was accompanied by damaging mudflows.