Cuicocha
Encyclopedia
Cuicocha is a 3 km (2 mi) wide caldera
and crater lake
at the foot of Cotacachi Volcano
in the Cordillera Occidental of the Ecuador
ian Andes
.
Its name comes from the Kichwa
indigenous language and means "Lago del Cuy" or Guinea Pig Laguna in English. It was given this name due to the guinea pig shape of the largest Island in the middle of the laguna. These animals play a significant part in the everyday life of Ecuadorians, as they reproduces rapidly and need a minimum of food and care to survive. They make for a high protein meal especially for populations living in high altitude.
The caldera was created by a massive phreatic eruption
about 3100 years ago that generated about 5 cubic kilometres (6.54 billion cubic yards) of pyroclastic flow
and covered the surrounding area in volcanic ash
up to 20 cm (8 inches) deep. The volcano has been dormant since that time. In combination with other eruptions from nearby Imbabura
, Mojanda
, Cotacachi, and Cayambe
, Cuicocha is responsible for the fertile soil of the Otavalo valley
.
The crater lake within the Cuicocha caldera contains four dacitic
lava dome
s which form two steep forested islands: Yerovi, the smaller, and Teodoro Wolf, the larger. People are prohibited on both. The rim of the caldera is extremely steep — so steep, in fact, that the accumulation of sediment
is insufficient for most hydrophyte vegetation. An older lava dome from the Pleistocene
forms part of the eastern rim. The lake, which is 200 m (656 ft) deep at its deepest point, is highly alkali
ne and contains little life. It has no known outlet.
The intra-caldera islands, on the other hand, support some wildlife, most notably the Silvery Grebe
, which lives around the reeds
and feeds on small fish, frogs, crayfish, small water snakes, seeds of water plants, and insects. The bird is found in upper temperate and lower páramo
zones throughout the Andes, but little is known about the species. In 1974 a census was taken of the population of grebes at Cuicocha and 44 birds were found.
Cuicocha forms the southern end of the Cotacachi-Cayapas Ecological Reserve. During the second day of Inti Raymi
(or Sun Festival) every summer solstice
, indigenous shaman
use Cuicocha as a bath for ritual cleansing and purification.
Caldera
A caldera is a cauldron-like volcanic feature usually formed by the collapse of land following a volcanic eruption, such as the one at Yellowstone National Park in the US. They are sometimes confused with volcanic craters...
and crater lake
Crater lake
A crater lake is a lake that forms in a volcanic crater or caldera, such as a maar; less commonly and with lower association to the term a lake may form in an impact crater caused by a meteorite. Sometimes lakes which form inside calderas are called caldera lakes, but often this distinction is not...
at the foot of Cotacachi Volcano
Cotacachi Volcano
Cotacachi is a dormant volcano in the Western Cordillera of the northern Ecuadorian Andes, in the west of Imbabura Province....
in the Cordillera Occidental of the Ecuador
Ecuador
Ecuador , officially the Republic of Ecuador is a representative democratic republic in South America, bordered by Colombia on the north, Peru on the east and south, and by the Pacific Ocean to the west. It is one of only two countries in South America, along with Chile, that do not have a border...
ian Andes
Andes
The Andes is the world's longest continental mountain range. It is a continual range of highlands along the western coast of South America. This range is about long, about to wide , and of an average height of about .Along its length, the Andes is split into several ranges, which are separated...
.
Its name comes from the Kichwa
Kichwa
Kichwa is a Quechuan language, and includes all Quechua varieties spoken in Ecuador and Colombia by approximately 2,500,000 people...
indigenous language and means "Lago del Cuy" or Guinea Pig Laguna in English. It was given this name due to the guinea pig shape of the largest Island in the middle of the laguna. These animals play a significant part in the everyday life of Ecuadorians, as they reproduces rapidly and need a minimum of food and care to survive. They make for a high protein meal especially for populations living in high altitude.
The caldera was created by a massive phreatic eruption
Phreatic eruption
A phreatic eruption, also called a phreatic explosion or ultravulcanian eruption, occurs when rising magma makes contact with ground or surface water. The extreme temperature of the magma causes near-instantaneous evaporation to steam, resulting in an explosion of steam, water, ash, rock, and...
about 3100 years ago that generated about 5 cubic kilometres (6.54 billion cubic yards) of pyroclastic flow
Pyroclastic flow
A pyroclastic flow is a fast-moving current of superheated gas and rock , which reaches speeds moving away from a volcano of up to 700 km/h . The flows normally hug the ground and travel downhill, or spread laterally under gravity...
and covered the surrounding area in volcanic ash
Volcanic ash
Volcanic ash consists of small tephra, which are bits of pulverized rock and glass created by volcanic eruptions, less than in diameter. There are three mechanisms of volcanic ash formation: gas release under decompression causing magmatic eruptions; thermal contraction from chilling on contact...
up to 20 cm (8 inches) deep. The volcano has been dormant since that time. In combination with other eruptions from nearby Imbabura
Imbabura Volcano
Imbabura is an inactive stratovolcano in northern Ecuador. Although it has not erupted for at least 14,000 years, it is not thought to be entirely extinct. Imbabura is intermittently capped with snow and has no permanent glaciers....
, Mojanda
Mojanda
Mojanda is an inactive stratovolcano of the Eastern Cordillera of the Andes in northern Ecuador. A summit caldera, which was produced by an explosive Plinian Eruption that marked the end of Mojanda activity 200,000 years ago, is presently occupied by three crater lakes: Caricocha , Yanacocha,...
, Cotacachi, and Cayambe
Cayambe (volcano)
Cayambe is the name of a volcano located in the Cordillera Oriental, a branch of the Ecuadorian Andes. It is located in Pichincha province some 70 km northeast of Quito. It is the third highest mountain in Ecuador....
, Cuicocha is responsible for the fertile soil of the Otavalo valley
Otavalo
Otavalo, capital of Otavalo Canton, is a largely indigenous town in the Imbabura Province of Ecuador. The town has about 50,000 inhabitants and is surrounded by the peaks of Imbabura 4,630m, Cotacachi 4,995m, and Mojanda volcanoes.- The market :...
.
The crater lake within the Cuicocha caldera contains four dacitic
Dacite
Dacite is an igneous, volcanic rock. It has an aphanitic to porphyritic texture and is intermediate in composition between andesite and rhyolite. The relative proportions of feldspars and quartz in dacite, and in many other volcanic rocks, are illustrated in the QAPF diagram...
lava dome
Lava dome
|250px|thumb|right|Image of the [[rhyolitic]] lava dome of [[Chaitén Volcano]] during its 2008–2009 eruption.In volcanology, a lava dome is a roughly circular mound-shaped protrusion resulting from the slow extrusion of viscous lava from a volcano...
s which form two steep forested islands: Yerovi, the smaller, and Teodoro Wolf, the larger. People are prohibited on both. The rim of the caldera is extremely steep — so steep, in fact, that the accumulation of sediment
Sediment
Sediment is naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of fluids such as wind, water, or ice, and/or by the force of gravity acting on the particle itself....
is insufficient for most hydrophyte vegetation. An older lava dome from the Pleistocene
Pleistocene
The Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....
forms part of the eastern rim. The lake, which is 200 m (656 ft) deep at its deepest point, is highly alkali
Alkali
In chemistry, an alkali is a basic, ionic salt of an alkali metal or alkaline earth metal element. Some authors also define an alkali as a base that dissolves in water. A solution of a soluble base has a pH greater than 7. The adjective alkaline is commonly used in English as a synonym for base,...
ne and contains little life. It has no known outlet.
The intra-caldera islands, on the other hand, support some wildlife, most notably the Silvery Grebe
Silvery Grebe
The Silvery Grebe is a species of grebe in the Podicipedidae family.It is found in Argentina, Chile, the Falkland Islands and Paraguay as well as Andean regions of Bolivia, Colombia, Ecuador and Peru. It is a vagrant to Brazil....
, which lives around the reeds
Phragmites
Phragmites, the Common reed, is a large perennial grass found in wetlands throughout temperate and tropical regions of the world. Phragmites australis is sometimes regarded as the sole species of the genus Phragmites, though some botanists divide Phragmites australis into three or four species...
and feeds on small fish, frogs, crayfish, small water snakes, seeds of water plants, and insects. The bird is found in upper temperate and lower páramo
Páramo
The term páramo can refer to a variety of ecosystems. Some ecologists describe the páramo broadly as “all high, tropical, montane vegetation above the continuous timberline”. A more narrow term classifies the páramo according to its regional placement - specifically located in “the northern Andes...
zones throughout the Andes, but little is known about the species. In 1974 a census was taken of the population of grebes at Cuicocha and 44 birds were found.
Cuicocha forms the southern end of the Cotacachi-Cayapas Ecological Reserve. During the second day of Inti Raymi
Inti Raymi
During the Inca Empire, the Inti Raymi was the most important of four ceremonies celebrated in Cusco, as related by Inca Garcilaso de la Vega. The celebration took place in the Haukaypata or the main plaza in the city....
(or Sun Festival) every summer solstice
Solstice
A solstice is an astronomical event that happens twice each year when the Sun's apparent position in the sky, as viewed from Earth, reaches its northernmost or southernmost extremes...
, indigenous shaman
Shamanism
Shamanism is an anthropological term referencing a range of beliefs and practices regarding communication with the spiritual world. To quote Eliade: "A first definition of this complex phenomenon, and perhaps the least hazardous, will be: shamanism = technique of ecstasy." Shamanism encompasses the...
use Cuicocha as a bath for ritual cleansing and purification.