Nevado del Ruiz
The Nevado del Ruiz known as La Mesa de Herveo is located on the border of the departments of Caldas and Tolima in Colombia, about 129 kilometers west of the capital city Bogotá. It is a stratovolcano composed of many layers of lava alternating with hardened volcanic ash and other pyroclastic rocks. Nevado del Ruiz has been active for about two million years, since the Early Pleistocene or Late Pliocene, with three major eruptive periods; the current volcanic cone formed during the present eruptive period, which began 150 thousand years ago. The volcano generates Vulcanian to Plinian eruptions, which produce swift-moving currents of hot gas and rock called pyroclastic flows; these eruptions cause massive lahars, which pose a threat to human life and the environment. The impact of such an eruption is increased as the hot gas and lava melt the mountain's snowcap, adding large quantities of water to the flow. On November 13, 1985, a small eruption produced an enormous lahar that buried and destroyed the town of Armero in Tolima, causing an estimated 25,000 deaths.
This event became known as the Armero tragedy—the deadliest lahar in recorded history. Similar but less deadly incidents occurred in 1595 and 1845, consisting of a small explosive eruption followed by a large lahar; the volcano is part of Los Nevados National Natural Park, which contains several other volcanoes. The summit of Nevado del Ruiz is covered by large glaciers; the volcano continues to pose a threat to the nearby towns and villages, it is estimated that up to 500,000 people could be at risk from lahars from future eruptions. Today, the Nevado del Ruiz volcano is monitored by the Volcanic and Seismic Observatory of Manizales. Nevado del Ruiz, which lies about 129 kilometers west of Bogotá, is part of the Andes mountain range; the volcano is part of the Ruiz–Tolima volcanic massif, a group of five ice-capped volcanoes which includes the Tolima, Santa Isabel and Machin volcanoes. The massif is located at the intersection of four faults. Nevado del Ruiz lies within the Pacific Ring of Fire, a region that encircles the Pacific Ocean and contains some of the world's most active volcanoes.
It is the third most northerly of the volcanoes lying in the North Volcanic Zone of the Andean Volcanic Belt, which contains 75 of the 204 Holocene-age volcanoes in South America. The Andean Volcanic Belt is produced by the eastward subduction of the oceanic Nazca Plate beneath the South American continental plate; as is the case for many subduction-zone volcanoes, Nevado del Ruiz can generate explosive Plinian eruptions with associated pyroclastic flows that can melt snow and glaciers near the summit, producing large and sometimes devastating lahars. Like many other Andean volcanoes, Nevado del Ruiz is a stratovolcano: a voluminous conical volcano consisting of many strata of hardened lava and tephra including volcanic ash, its lavas are andesitic–dacitic in composition. The modern volcanic cone comprises five lava domes, all constructed within the caldera of an ancestral Ruiz volcano: Nevado El Cisne, Alto de la Laguna, La Olleta, Alto la Pirana, Alto de Santano, it covers an area of more than 200 square kilometers.
The mountain's broad summit includes the Arenas crater, 1 kilometre in diameter and 240 meters deep. Nevado del Ruiz, as its neighbours to the southwest Nevado El Cisne and Nevado de Santa Isabel is located over the Palestina Fault that crosscuts the underlying El Bosque Batholith, dated at 49.1 ± 1.7 Ma. The summit of the volcano has steep slopes inclining from 20 to 30 degrees. At lower elevations, the slopes become less steep. From there on, foothills stretch to the edge of the Magdalena River, north of the volcano and the Cauca River to the west. On the two major sides of the summit, headwalls show. At times, ice on the summit has melted, generating devastating lahars, including the continent's deadliest eruption in 1985. On the volcano's southwest flank is the pyroclastic cone La Olleta, not active, but may have erupted in historical times; the summit of Nevado del Ruiz is covered by glaciers, which formed over many thousands of years, have retreated since the last glacial maximum. From 28,000 to 21,000 years ago, glaciers occupied about 1,500 square kilometers of the Ruiz–Tolima massif.
As late as 12,000 years ago, when the ice sheets from the last glacial period were retreating, they still covered 800 square kilometers. During the Little Ice Age, which lasted from about 1600 to 1900 CE, the ice cap covered 100 square kilometers. Since the glaciers have retreated further because of atmospheric warming. By 1959, the massif's glaciated area had dropped to 34 square kilometers. Since the 1985 eruption, which destroyed about 10% of the summit ice cover, the area of Nevado del Ruiz covered by glaciers has halved—from 17 to 21 square kilometers just after the eruption to about 10 square kilometers in 2003; the glaciers reached altitudes as low as 4,500 meters in 1985 but have now retreated to elevations of 4,800–4,900 meters. The ice cap is 50 meters thick on average, it is thickest in parts of the summit plateau and under the Nereides Glacier on the southwestern slopes, where it is as deep as 190 meters. Glaciers on the northern and, to a lesser extent
Cordillera Occidental (Colombia)
The Cordillera Occidental is the lowest in elevation of the three branches of the Colombian Andes. The average altitude is 2,000 m and the highest peak is Cerro Tatamá at 4,100 m; the range extends from south to north dividing from the Colombian Massif in Nariño Department, passes north through Cauca, Valle del Cauca, Chocó, Caldas Departments to the Paramillo Massif in Antioquia and Córdoba Departments. From this massif the range divides further to form the Serranías de Ayapel, San Jerónimo and Abibe. Only to recede into the Caribbean plain and the Sinú River valley; the western part of the mountain range belongs to the Pacific region, with the San Juan River being the main watershed, while the eastern part belongs to the Cauca River basin. The northern and northwestern parts belong to the Atlantic Slope, with the Atrato and Sinú Rivers being the main watersheds; the Cordillera Occidental is separated from the coastal Baudó Mountains by the Atrato River. Cerro Tatamá - 4,100 m - Chocó & Risaralda Farallones de Cali - 4,050 m - Valle del Cauca Farallones de Citará - 4,050 m - Antioquia Páramo de Frontino - 3,950 m - Antioquia Cerro Caramanta - 3,900 m - Antioquia, Caldas & Risaralda Cerro Napi - 3,860 m - Cauca Alto Musinga - 3,850 m - Antioquia Cerro Calima - 3,840 m - Valle del Cauca Cerro Paramillo - 3,730 m - Antioquia Cerro Ventana - 3,450 m - Valle del Cauca & Chocó The West Andes have the following nationally protected areas from south to north: PNN Munchique PNN Farallones de Cali PNN Tatamá PNN Las Orquídeas PNN ParamilloOther areas under consideration for national protection include: Serranía del Pinche Serranía de los Paraguas Yotoco Forest Reserve Bitaco River Forest Reserve Dapa Calima Lake Geography of Colombia Andean Region, Colombia Cordillera Central Cordillera Oriental
Serranía del Perijá
The Serranía del Perijá, Cordillera de Perijá or Sierra de Perijá is a mountain range, an extension of the eastern Andean branch, in northern South America, between Colombia and Venezuela, ending further north in the Guajira Desert, a total distance of about 310 kilometres. It separates the Maracaibo Basin from the Cesar-Ranchería Basin; some of the area has been considered as a Fauna Sanctuary. Starting at the southernmost point, near Ocaña, this mountain range forms the boundary between the Colombian departments of Norte de Santander and Cesar, as the range progresses north, it forms the international boundary between Venezuela and Colombia. Included in the range are the Sierra Motilones, Sierra Valledupar, Sierra Oca; the highest point is Cerro de Las Tetas at 3630 meters, followed by Cerro Irapa at 3540 m. Serranía de Macuira at 864 m. and Cerro Aceite at 853 m. The range is 58% in Venezuela, 42% in Colombia. Venezuela has set aside a substantial part of the central part of the range as a national park, Colombia has a smaller one.
In the Venezuelan portion there are Amerindian reservations for the Yucpa and Barí people, in Colombia for the Iroko and Sokorpa people. Venezuela has started a colonialization border plan building new communities along the border in the Perijá; the town of Cojoro was the first one completed, followed by communities for the Wayuu and Goajira peoples. The climate is tropical humid forests, with cultivation of coffee and papaver flowers, it is a hot spot in the Colombian Conflict serving as home to parts of two FARC blocs called the Caribbean Bloc of the FARC-EP and the Middle Magdalena Bloc of the FARC-EP. and an ELN guerrilla column, that have strayed into Venezuelan territory. ^ —Peakbagger.com: Perija-Guajira ^ VHeadline.com Sunday, January 18, 1998, New border town ready in April as another gets lined up for flash point Perija, by Patrick J. O'Donoghue ^ fac.mil.co,Accessed March 9, 2007, Colombian Air Force.
Nevado del Huila
Nevado del Huila at 5,364 metres, is the highest volcano in Colombia, located at the tripoint of the departments of Huila and Cauca. It is visible from the city of Cali; the andesitic volcano is located on top of the Ibagué Batholith. After being dormant for more than 500 years, the volcano showed heavy signs of activity in 2007 and 2008; as of February 20, 2007, there were more than 7000 "minor" seismic events, a high state of alert was in place for the departments of Cauca, Huila and Valle del Cauca. The volcano erupted twice in April 2007, once in April 2008 and again in November 2008. Any eruption would affect the small villages around the volcano Páez, where their inhabitants still have in memory the eruption of the Nevado del Ruiz volcano and the destruction of Armero. On April 18, 2007, the volcano erupted twice causing avalanches into the Paez River. More than 4,000 people were evacuated with no casualties reported. Nevado del Huila became active again in March 2008. After a multitude of earthquakes inside the volcano, Colombian authorities declared a state of yellow alert on March 18.
The state of alert was increased to orange on March 29, meaning an eruption could be expected within two weeks. Hundreds of people were evacuated. On April 14, 2008 at 11:08 pm, an ash eruption took place, prompting the government to issue a red alert and evacuate 13,000 to 15,000 people from around the mountain; the state of red alert was again lowered to orange following diminished activity. On November 20, 2008, the volcano erupted at 02:45 GMT according to Colombian Institute of Geology and Mining. An immediate mass-scale evacuation was put in motion by the Colombian authorities, which the inhabitants of some towns refused. There were no injured reported at the time. On November 23, 2008, BBC News, citing Colombian authorities, announced that the eruption had claimed ten lives, with 12,000 nearby residents being evacuated and emergency services unable to reach many of the more remote affected locations; the eruption had triggered an avalanche of earth and debris that damaged houses and crops on plantations.
The three small towns of Paicol, La Plata and Belalcázar along the Páez River were affected by this eruption. Extensive instrumentation of the volcano, put in place by the existing national system for prevention and care of disasters, which includes training of local inhabitants in high-risk regions and deployment of alarms in nearby towns prevented large-scale deaths. President Álvaro Uribe ordered the Air Force of Colombia to create an "air bridge" to provide supplies for cut off towns along the Páez River. List of volcanoes in Colombia List of volcanoes by elevation Gómez, Jorge. 1999. Plancha 322 - Santa María - 1:100,000, 1. INGEOMINAS. Accessed 2017-06-06. Global Volcanism Program Nevado del Huila Volcano Observatory
The Altiplano Cundiboyacense is a high plateau located in the Eastern Cordillera of the Colombian Andes covering parts of the departments of Cundinamarca and Boyacá. The altiplano corresponds to the ancient territory of the Muisca; the Altiplano Cundiboyacense comprises three distinctive flat regions. The average altitude of the altiplano is about 2,600 metres above sea level but ranges from 2,500 metres to 4,000 metres. Altiplano in Spanish means "high plain" or "high plateau", the second part is a combination of the departments Cundinamarca and Boyacá; the limits of the Altiplano are not defined. The high plateau is enclosed by the higher mountains of the Eastern Ranges, with the Sumapaz mountains in the south and Chingaza to the east; the Tenza Valley is located to the east of the Altiplano and the Ocetá Páramo and Chicamocha Canyon are situated to the northeast. The Altiplano is subdivided into three major valleys, from northeast to southwest: Iraca Valley Ubaté–Chiquinquirá Valley Bogotá savanna The average temperature on the Altiplano Cundiboyacense is 14 °C, ranging from 0 °C to 24 °C.
The dryest months of the year are from December to March, while rain is more common in April, September and November. From June to August strong winds are present. Hail is common on the Altiplano; the Altiplano Cundiboyacense contains various Andean unique ecosystems. 60% of all páramos in the world are situated in Colombia and Boyacá has the most relative area of páramos. Boyacá is the department. To the south the Sumapaz Páramo forms a natural boundary of the Altiplano. Chingaza contains páramo vegetation. On the Altiplano the microclimate of the surroundings of Lake Iguaque produces a páramo; the Altiplano Cundiboyacense is formed as part of the uplift of the Eastern Ranges of the Colombian Andes since Neogene times. Hydrothermal activity in fractures of the forming Andean chain left its trace in the form of the many emeralds found in the western and eastern parts of the Altiplano. From the Early Cretaceous until the Eocene, the region of the present-day Altiplano was dominated by a marine environment, as part of the long inland sea of northern South America.
In these warm tropical seas a fauna of ichthyosaurs and pliosaurs developed, with important finds in the Paja Formation of Villa de Leyva. During the Late Eocene-Early Oligocene epochs, South America became detached from its longest connected former member of Pangea; the isolation of the South American paleocontinent led to a large biodiversity of New World species. The dominating group of top predators and scavengers for decades of millions of years on the continent were the terror birds. Fossils of terror birds have been found throughout South America, with a major collection from current Argentina, where the biggest terror bird, roamed the paleopampas in the early Miocene; the forming Andes created a hilly landscape in the regions bordering the former sea inlet from the proto-Caribbean. Other land animals in the Tertiary were the xenungulate Etayoa bacatensis, evidence for, found in 1987 in the Bogotá Formation of the southern Altiplano; the biodiversity and former tranquility of the isolated ecosystem changed during the Pliocene, when the Panama Block emerged from the seas and formed a transferable connection with isolated North America.
This Great American Biotic Interchange led to a drastic rearrangement of South American fauna. Migrating species from North America replaced many successful South American animals, among which the terror birds; the Late Pleistocene of the Altiplano Cundiboyacense has been analysed in detail through various methods based on fossils found on the Altiplano. Pleistocene megafauna inhabited the glacial highlands of the eastern Andean chain; the climate in the glacials and stadials led to the formation of various prehistoric lakes in the valleys of the Altiplano. The Ubaté-Chiquinquirá Valley in the northwest of the Altiplano was covered with a lake, of which the current Lake Fúquene is a retreating remainder. To the extreme northeast, in Soatá, another Pleistocene lake was present; the largest paleolake in the latest Pleistocene was Lake Humboldt or Lake Bogotá covering the Bogotá savanna. The lake, some 4,000 square kilometres in size, at that time would have been seventy times larger than the biggest lake of Colombia.
Lake Tota is the remnant of a Pleistocene glacial lake higher up the Altiplano to the east. Lake Humboldt is thought to have existed until around 30,000 years ago with as modern remaining water bodies Lake Herrera, wetlands of Bogotá and the Bogotá River. Lake Humboldt had an irregular shoreline with an island in the centre; the Altiplano Cundiboyacense is regarded one of eleven archaeological regions of Colombia. The earliest evidence of human occupation in the region has been found in Pubenza, to the west of the Altiplano, dating to 16,000 years BP. On the Altiplano, the oldest findings are dated at 12,400 ± 160 years in El Abra. Younger occurrences of settlement by hunter-gatherers have been discovered at Tibitó, with an estimated age of 11,740 +/- 110 years BP and Tequendama dated at 10,920 ± 260 years BP. In the earliest ages of human population prehistoric animals as the Cuvieronius and Equus amerhippus were living on the Altiplano. Dated excavations have revealed a transition from a hunter
Geography of Colombia
The Republic of Colombia is a transcontinental country situated in the northwest of South America, with territories in North America. Colombia is bordered to the northwest by Panama. Colombia is the 26th largest nation in the world and the fourth-largest country in South America after Brazil and Peru. Despite its large territory, Colombia's population is not evenly distributed, with most Colombians living in the mountainous western portion of the country as well as the northern coastline, most living in or near the capital city of Bogotá; the southern and eastern portions of the country are sparsely inhabited tropical rainforest, inland tropical plains containing large estates or large livestock farms and gas production facilities, small farming communities and indigenous tribes. Colombia classifies its geography into five natural regions, from the Andes mountain range, a region shared with Ecuador, Venezuela. Colombia is the only South American country which borders both Pacific Oceans. Despite this The World Factbook makes no difference between Amazon region of Colombia and the Orinoquia region of Colombia.
The World Factbook considers most appropriate to divide the country into four geographic regions: the Andean highlands, consisting of the three Andean ranges and intervening valley lowlands. The chief western mountain range, the Cordillera Occidental, is a moderately high range with peaks reaching up to about 15,000 ft; the Cauca River Valley, an important agricultural region with several large cities on its borders, separates the Cordillera Occidental from the massive Cordillera Central. Several snow-clad volcanoes in the Cordillera Central have summits that rise above 17,000 ft; the valley of the slow-flowing and muddy Magdalena River, a major transportation artery, separates the Cordillera Central from the main eastern range, the Cordillera Oriental. The peaks of the Cordillera Oriental are moderately high; this range differs from Colombia's other mountain ranges. In the east, the sparsely populated, flat to rolling eastern lowlands called llanos cover 60 percent of the country's total land area.
This cross section of the republic does not include two of Colombia's regions: the Caribbean coastal lowlands and the Sierra Nevada de Santa Marta, both in the northern part of the country. The lowlands in the west are swampy; the Guajira Peninsula in the east is semiarid. The Sierra Nevada de Santa Marta is a spectacular triangular snowcapped block of rock that towers over the eastern part of this lowland. Here can be found the highest peak of the country named Pico Cristobal Colon. Near the Ecuadorian frontier, the Andes Mountains divide into three distinct parallel chains, called cordilleras, that extend northeastward to the Caribbean Sea. Altitudes reach more than 18,700 ft, mountain peaks are permanently covered with snow; the elevated basins and plateaus of these ranges have a moderate climate that provides pleasant living conditions and in many places enables farmers to harvest twice a year. Torrential rivers on the slopes of the mountains produce a large hydroelectric power potential and add their volume to the navigable rivers in the valleys.
In the late 1980s 78 percent of the country's population lived in the Andean highlands. The Cordillera Occidental in the west, the Cordillera Central in the center, the Cordillera Oriental in the east have different characteristics. Geologically, the Cordillera Occidental and the Cordillera Central form the western and eastern sides of a massive crystalline arch that extends from the Caribbean lowlands to the southern border of Ecuador; the Cordillera Oriental, however, is composed of folded stratified rocks overlying a crystalline core. The Cordillera Occidental is low and is the least populated of the three cordilleras. Summits do not have permanent snows. Few passes exist, although one, about 4,985 ft above sea level provides the major city of Cali with an outlet to the Pacific Ocean; the low elevation of the cordillera permits dense vegetation, which on the western slopes is tropical. The Cordillera Occidental is separated from the Cordillera Central by the deep rift of the Cauca Valley; the Río Cauca rises within 124 mi of the border with Ecuador and flows through some of the best farmland in the country.
After the two cordilleras converge, the Cauca Valley becomes a deep gorge all the way to the Caribbean lowlands. The Cordillera Central is the loftiest of the mountain systems, its crystalline rocks form a towering wall dotted with snow-covered volcanoes, 500 mi long. There are no plateaus in this range and no passes under 10,825 ft; the highest peak in this range, the Nevado del Huila, reaches 17,602 ft above sea level. The second highest peak is a volcano, Nevado del Ruiz, which erup
Serranía de Macuira
Serranía de Macuira is a mountain range in northern Colombia located in the municipality of Uribia, La Guajira. The Serrania de Macuira stands in the middle of the La Guajira Desert at 864 m isolated from the Sierra Nevada de Santa Marta and the Eastern Ranges of the Colombian Andes; the range is a protected area. The Serranía de Macuira measures around 35 kilometres in length and is circa 10 kilometres wide, at 10 kilometres from the Caribbean sea; the range is composed of three mountain massifs. The area is home to numerous species of fauna and flora and due to its high humidity caused by the trade winds and its proximity to the Caribbean sea it presents a forest of dwarf trees and cloud forests; the frog Allobates wayuu is only known from the Serranía de Macuira. National Natural Parks of Colombia: Macuira