Report on Guagua Pichincha (Ecuador) — 10 January-16 January 2001
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 10 January-16 January 2001
Managing Editor: Gari Mayberry
Please cite this report as:
Global Volcanism Program, 2001. Report on Guagua Pichincha (Ecuador). In: Mayberry, G (ed.), Weekly Volcanic Activity Report, 10 January-16 January 2001. Smithsonian Institution and US Geological Survey.
0.171°S, 78.598°W; summit elev. 4784 m
All times are local (unless otherwise noted)
Guagua Pichincha has been producing fewer seismic events (~100/day) with the continuing growth of dome #9. During the week of 7-13 January the LP events were of greater magnitude and depth, registering on stations 10 km from the crater. Diego Viracucha of the Instituto Geofisica reported via radio on the morning of 14 January that a new crater appeared to be forming in dome #9. Diego informed two assistants that he was going to move several hundred meters W of seismic station "Pino" to take photos. While attempting that work he apparently slipped and fell 200 m into the caldera. He probably died immediately from head wounds and internal injuries. The site of the accident was 2.5 hours from GGP Refuge and it took all day to recover the body; because of the climatic conditions a helicopter could not be used. Recovery of the body was accomplished by six volcanologists from the IG, the Civil Defense, the Guards of the Refuge, the Red Cross, an elite group of police, various mountaineering groups, and family members. A cousin, Galo Viracucha, was injured during the recovery effort and later died as a result.
Geologic Background. Guagua Pichincha and the older Pleistocene Rucu Pichincha stratovolcanoes form a broad volcanic massif that rises immediately to the W of Ecuador's capital city, Quito. A lava dome is located at the head of a 6-km-wide breached caldera that formed during a late-Pleistocene slope failure ~50,000 years ago. Subsequent late-Pleistocene and Holocene eruptions from the central vent in the breached caldera consisted of explosive activity with pyroclastic flows accompanied by periodic growth and destruction of the central lava dome. One of Ecuador's most active volcanoes, it is the site of many minor eruptions since the beginning of the Spanish era. The largest historical eruption took place in 1660, when ash fell over a 1000 km radius, accumulating to 30 cm depth in Quito. Pyroclastic flows and surges also occurred, primarily to then W, and affected agricultural activity, causing great economic losses.