Chimborazo

Article

July 5, 2022

The inactive volcano Chimborazo ([ˌtʃimboˈɾaθo], [ˌt͡ʃimboˈɾaso]), also German Tschimborasso, is the highest mountain in Ecuador at 6263 m above sea level. Because of its proximity to the equator, the peak of Chimborazo is the most distant point on the earth's surface from the center of the earth.

Geography and Geology

Location

The Chimborazo is located in the western cordillera of the Andes, about 165 km south of the equator, in the province named after it. Its neighboring peak is the 5018 meter high Carihuairazo. The majestic peak of the Chimborazo rises 2500 m from the 3500 m to 4000 m high plateau surrounding it. Its diameter at the base is about 20 km. In ideal conditions, mostly in the winter months (December-April), the summit can be seen from the coastal city of Guayaquil, 140 km away. The main cities in its vicinity are Riobamba (about 30 km south-east), Ambato (about 30 km north-east) and Guaranda (about 25 km south-west of the mountain). The Chimborazo lies within the nature reserve "Reserva de Produccion Faunistica Chimborazo", which serves to protect the habitat of the camelid vicuña, llama and alpaca native to the Andes.

Glaciers

The upper part of the mountain from about 5100 meters is glaciated. Individual glacier arms reach down to 4600 m. The Chimborazo glaciers provide the water supply for large parts of the provinces of Bolívar and Chimborazo. The glaciers have lost significant mass in recent decades due to global warming, ash cover from recent volcanic activity of its eastern neighbor Tungurahua (Schotterer et al. 2003), and the El Niño phenomenon. As with other Ecuadorian mountains, ice from the Chimborazo glaciers is mined by so-called hieleros (from Spanish hielo for ice) to be sold in the markets of Guaranda and Riobamba. In the past, the ice was transported down to coastal lowland towns like Babahoyo or Vinces (Borja 2004). Baltazar Ushca is the only remaining Hielero who still regularly climbs up to the Chimborazo ice mines.

Volcanism

The volcanism at Chimborazo is a result of the subduction of the Nazca plate under the South American continent and is predominantly andesitic-dacistic in character. The stratovolcano erupted for the last time around the year 550 (± 150 years).

Height

The Chimborazo is the highest mountain in Ecuador, the northernmost six-thousander in South America and higher than all the northern mountains in America. A height of 6310 m was long attributed to him. A differential GPS measurement carried out in 2016 found an altitude of 6263 m. SRTM data indicate that this height is more likely than the widely reported 6310 m. Chimborazo was thought to be the tallest mountain on earth before the Himalayas were surveyed. However, measurements by George Everest in 1856 showed that many Himalayan peaks, especially Mount Everest, are higher than Chimborazo. Today 26 higher mountains are known in the Andes. The highest mountain there is the Aconcagua at 6961 m, the second highest and highest volcano on earth is the Nevado Ojos del Salado at 6893 m.

Distance from the axis of the earth and from the center of the earth

Because of its proximity to the equator, the peak of Chimborazo is the point on the earth's surface furthest from the center of the earth. The fact that it surpasses the much higher Mount Everest is because the earth is not a sphere due to the rotation and the resulting centrifugal force, but an ellipsoid of revolution, the radius of which is smaller at the poles and larger at the equator. Taking the center of the earth as a reference point, according to Senne (2000) the Chimborazo (1° south latitude, 6384.557 km from the center of the earth) surpasses Mount Evere