- VolcanoEl Altar is an extinct stratovolcano on the western side of Sangay National Park in Ecuador, 170 km south of Quito. Altar was last active about 2 million years ago and contains a caldera open to the west, which contains a lake. A large rockslide caused fatalities in 2000. On 13 October 2000, a large block of andesitic breccia with a volumne of ca. 1.5 million m3 rock broke off from near the summit and slid 900 m down into a caldera lake. This impact caused a 50 m high tsunami which overflowed the caldera and produced a lahar, that killed 13 people
Volcano type caldera (probably) extinct Location Ecuador Summit elevation 5321 m / 17,457 ft Altar volcano eruptions ca. 2 million years ago
landslide-caused tsunami in 2000
uncertain reports from 1460 AD
Typical eruption style explosiveInca legends report that the top of Altar collapsed after seven years of activity in about 1460, but the caldera is considered to be much older than this by geologists. 9 major peaks over 5,000 metres (16,400 ft) form a horseshoe-shaped ridge about 3 km across, surrounding a central basin that contains a crater lake at about 4,200 m (13,800 ft), known as Laguna Collanes or Laguna Amarilla.
- Hall, Minard L. (1977). "El Volcanismo en el Ecuador". Sección Nacional del Ecuador. p. 120 pp
- Smithsonian / GVP additonal reports for Altar