Fumarole activity inside crater floor, following seismic activity several weeks earlier.
Sulphur crystals on vent inside crater floor.
View of road cut, visible while taking road from town of Lloa to the government hut near summit of crater. Elevation at this point approximately 13,000 feet. Shows strata of expelled material and soil for recent periods of eruptions.
Outside slope of crater showing pumice.
Robert Runyard is a contributor to the quarterly magazine of the South American Explorers Club, the South American Explorer.