Eruptions at San Pedro are reported from possibly 1885, when a newspaper from Valparaiso reported strong shaking of the earth, the emission of large quantities of white steam, and damage to the railway, houses and water pipes. Other eruptions reported from San Pedro were in 1901 when an eruption caused damage, May-August 1910, 1911, February 1938 and a minor event in December 1960. Additional eruptions are mentioned in records and dated to 1870, 1916, 1917, 1923. All these eruptions are uncertain and apparently of phreatic nature, and no geological evidence of them has been found. The timing of eruptions at San Pedro sometimes is unclear; one eruption reported from 1877 may instead have occurred in 1891 as there are two reports of an eruption before 1910 and they may either refer to one eruption with two candidate dates or two eruptions. This volcanic activity makes San Pedro one of the highest active volcanoes.