during the event. The last eruption before 1600 may have preceded that year by several centuries, based on the presence of volcanic eruption products buried under soil. Native people reportedly offered sacrifices and offerings to the mountain such as birds, personal clothing and sheep, although it is known that non-volcanic mountains in southern Peru received offerings as well. There have been no eruptions since 1600; a report of an eruption in 1667 is unsubstantiated and unclear owing to the sparse historical information. It probably reflects an eruption at Ubinas instead. Fumaroles and hot springs Fumaroles occur in the amphitheatre close to the three vents, on the third vent, and in association with dykes that crop out in the amphitheatre. In 1962, there were reportedly no fumaroles within the amphitheatre. These fumaroles produce white fumes and smell of rotten eggs. The fumarolic gas composition is dominated by water vapour, with smaller quantities of carbon dioxide and sulfur gases. Investigations in 2010 recorded temperatures of for the gases, with seasonal variations. Vegetation has grown at their vents. Hot springs occur in the region and some of these have been associated with Huaynaputina; these include Candagua and Palcamayo northeast, Agua Blanca and Cerro Reventado southeast from the volcano on the Río Tambo and Ullucan almost due west. The springs have temperatures ranging from and contain large amounts of dissolved salts. Cerro Reventado and Ullucan appear to be fed from magmatic water and a deep reservoir, while Agua Blanca is influenced by surface waters. 1600 eruption Based on historical records, Huaynaputina's eruption commenced on 19February 1600 (following earthquakes that began four days prior), with the earliest signs of the impending eruption perhaps in December1599. The duration of the eruption is not well constrained but may have lasted up to 12–19 hours. The event continued with earthquakes and ash fall for about two weeks and ended on 6March; the air was clear of ash from the eruption on 2April 1600. Some reports of late ash falls may be due to wind-transported ash, and there are no deposits from a supposed eruption in August1600; such reports may refer to mudflows or explosions in pyroclastic flows. The eruption of 1600 was initially attributed to Ubinas volcano and sometimes to El Misti. Priests observed and recorded the eruption from Arequipa, and the friar Antonio Vázquez de Espinosa wrote a second-hand account of the eruption based on a witness's