Major Volcanoes of the World
Major Volcanoes of the World : Avachinsky
| Colima | Galeras
| Mauna Loa | Mount
Etna | Mount Nyiragongo
| Mount Rainier | Mount
Unzen | Mount Vesuvius
| Sakurajima | Santamarķa
| Santorini | Taal
| Teide |
Ulawun
Galeras
Galeras (Urcunina among the indigenous people) is a volcano in Colombia, near the city of Pasto. Its summit lies 4,276 m (14,029 feet) above sea level. It has erupted frequently since the Spanish conquest, and in 1993, an eruption killed nine people, including five scientists who had descended into the volcano's crater to sample gases .
Geological history
Galeras has been an active volcano for at least a million years. Two major caldera-forming eruptions have occurred, the first about 560,000 years ago in an eruption which expelled about 15 cubic kilometres of material, and the second some time between 40,000 and 150,000 years ago, in a smaller but still sizable eruption of 2km³ of material. Subsequently, part of the caldera wall has collapsed, probably due to instabilities caused by hydrothermal activity, and later eruptions have built up a smaller cone inside the now horseshoe-shaped caldera.
At least six large eruptions have occurred in the last 5,000 years, most recently in 1886, and there have been at least 20 small to medium sized eruptions since the 1500s. In light of its violent eruption history and proximity to the 450,000 people of Pasto, Galeras was designated a Decade Volcano in 1991, identifying it as a target for detailed study as part of the United Nations' International Decade for Natural Disaster Reduction.
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