Sierra Nevada del Cocuy

From Wikipedia for FEVERv2
Jump to navigation Jump to search

Sierra Nevada del Cocuy_table_infobox_0

Parque Natural Sierra Nevada del Cocuy, Chita o GuicanSierra Nevada del Cocuy_header_cell_0_0_0
LocationSierra Nevada del Cocuy_header_cell_0_1_0 Departments of Arauca, Boyacá and CasanareSierra Nevada del Cocuy_cell_0_1_1
Nearest citySierra Nevada del Cocuy_header_cell_0_2_0 Tame, Arauca, ColombiaSierra Nevada del Cocuy_cell_0_2_1
CoordinatesSierra Nevada del Cocuy_header_cell_0_3_0 Sierra Nevada del Cocuy_cell_0_3_1
AreaSierra Nevada del Cocuy_header_cell_0_4_0 3,062 km (1,182 sq mi)Sierra Nevada del Cocuy_cell_0_4_1
EstablishedSierra Nevada del Cocuy_header_cell_0_5_0 1977Sierra Nevada del Cocuy_cell_0_5_1
Governing bodySierra Nevada del Cocuy_header_cell_0_6_0 SINAPSierra Nevada del Cocuy_cell_0_6_1

The Sierra Nevada del Cocuy Chita o Guican National Natural Park (or Sierra Nevada de Chita or Sierra Nevada de Güicán, Spanish: Parque Natural Sierra Nevada del Cocuy Chita o Guican is a national park and a series of highlands and glaciated peaks located within the Cordillera Oriental mountain range in the Andes Mountains of Colombia, at its easternmost point. Sierra Nevada del Cocuy_sentence_0

It also corresponds to the highest range of the Eastern Cordillera and holds the biggest glacial mass in South America, North of the Equator. Sierra Nevada del Cocuy_sentence_1

Since 1977, this region is protected within a National Natural Park (NNP-Cocuy) because of its fragile páramos, extraordinary bio-diversity and endemism, and its function as a corridor for migratory species under conditions of climate change. Sierra Nevada del Cocuy_sentence_2

Among the Sierra’s natural attractions are the remaining 18 ice-covered peaks (there were as many as 25 in the recent past), glacial lakes and waterfalls. Sierra Nevada del Cocuy_sentence_3

Geography Sierra Nevada del Cocuy_section_0

The Sierra Nevada del Cocuy lies within the Eastern Cordillera of the Colombian Andes, between the governmental jurisdictions of Boyacá and Arauca. Sierra Nevada del Cocuy_sentence_4

The Parque Nacional Natural el Cocuy (PNN El Cocuy) is the official national park in which the entirety of the glaciated peaks and a portion of regional páramo ecosystems are located. Sierra Nevada del Cocuy_sentence_5

The park has an area of 3000 km, of which 47% is covered by Páramo ecosystems. Sierra Nevada del Cocuy_sentence_6

The Sierra Nevada del Cocuy is also the largest glacial mass in Colombia, and meltwater from this glacier system feed the rivers Arauca, Casanare and Chicamocha, which in turn drain into the Magdalena and Orinoco basins. Sierra Nevada del Cocuy_sentence_7

Considerable portions of the Colombian and Venezuelan populations utilize the hydrologic resources from these basins for agriculture and sustenance. Sierra Nevada del Cocuy_sentence_8

Peaks Sierra Nevada del Cocuy_section_1

The Park contains several high peaks, many with permanent snow cover: Sierra Nevada del Cocuy_sentence_9

Pan de Azúcar (5120m), Diamante (4800 m), el Púlpito del Diablo (5100 m), Toti (4800 m), Portales (4800 m), Cóncavo (5200 m), Concavito (5100 m), San Pablines South (5180 m) and North (5200 m), Ritacuba Blanco (5330 m), Picacho (5030 m), Puntiagudo (5200 m), Ritacuba Negro (5300 m), el Castillo (5100 m), peak without name (5000 m), Sirara (5200 m). Sierra Nevada del Cocuy_sentence_10

An 1856 watercolor by Manuel María Paz is an early depiction of the Sierra Nevada del Cocuy in Casanare Province. Sierra Nevada del Cocuy_sentence_11

Geology Sierra Nevada del Cocuy_section_2

The Sierra Nevada del Cocuy region corresponds to the highest elevations of the Eastern Cordillera of the Colombian Andes. Sierra Nevada del Cocuy_sentence_12

The geologic origins of this mountain range are complex, but have been hypothesized to be the inversion of a Mesozoic extensional basin which gave way to a sedimentary basin that accumulated sediments for millions of years before its closure in the Paleogene. Sierra Nevada del Cocuy_sentence_13

The inversion and resulting shortening and compression values have been estimated to be in the order of 60 ± 20 km. Sierra Nevada del Cocuy_sentence_14

Additionally, it has been proposed that the relatively high topography of the Eastern Cordillera of the Colombian Andes around these areas is due to flat slab subduction of the Nazca plate under the South American plate for ~7.5 Million years . Sierra Nevada del Cocuy_sentence_15

In general, the geology of the Sierra Nevada del Cocuy consists on sedimentary rocks from the Cretaceous, broadly made up of sequences of quartzites, sandstones and fine-grained mudstones of Aptian and Cenomanian ages. Sierra Nevada del Cocuy_sentence_16

All of these rocks were deposited in marine or coastal environments and have been uplifted ~5 km since their deposition 100-120 Million Years Ago (Ma). Sierra Nevada del Cocuy_sentence_17

Most of this uplift is hypothesized to have taken place relatively recently at the end of the Cenozoic, starting around ~7Ma. Sierra Nevada del Cocuy_sentence_18

Biology and Ecology Sierra Nevada del Cocuy_section_3

Most of the area surrounding the glaciated peaks of the Sierra Nevada del Cocuy, and 55% of the entire area of the Parque Nacional Natural el Cocuy is dominated by páramo ecosystems. Sierra Nevada del Cocuy_sentence_19

These are high mountain (3000 – 4800 masl) tundra ecosystems characteristic of the tropical South American Andes and only occur in Costa Rica, Panamá, Colombia, Venezuela, Ecuador and Perú. Sierra Nevada del Cocuy_sentence_20

Páramos are foci of endemic diversity , widely diverse amongst themselves, and are crucial natural water regulation, carbon sequestration and climate change mitigation systems. Sierra Nevada del Cocuy_sentence_21

Because of the “island” effect of páramo distribution on separate mountain ranges, they present a unique flora and fauna derived from evolutionary processes, especially within the last 3 – 5 Ma. Sierra Nevada del Cocuy_sentence_22

One of the most characteristic plants of the páramo ecosystem, widely spread within the Sierra Nevada del Cocuy, is the yellow-flowered Frailejón (Espeletia lopezii), dominates de landscapes below the ice line, although many others, belonging to the Compositae, Lamiceae, Poceae and Rosaceae families can be found. Sierra Nevada del Cocuy_sentence_23

Animals, such as tapirs, brown bears, Andean condors, eagles, and páramo deer, and the iconic Spectacled Bear (or Andean Bear) can still be observed. Sierra Nevada del Cocuy_sentence_24

In spite of their ecological uniqueness, their importance for human sustenance and their inhospitable climatic and geographic conditions, the páramo systems in the Cocuy region have suffered environmental impacts, caused by many different parties. Sierra Nevada del Cocuy_sentence_25

From the pre-hispanic U’wa indigenous groups who first inhabited the region, to the colonial and present-day growing extent of agricultural lands, this landscape has been altered in ways that hinder its ability to store large amounts water and that fundamentally change the delicate biological communities by introducing invasive species or altering land use. Sierra Nevada del Cocuy_sentence_26

Since the colonial period, however, increased social and economic changes have led to the replacement of indigenous agricultural practices in the region with new productive land systems, that further introduced invasive species (~32% of plant species in the Sierra), cattle and sheep, and monocultures. Sierra Nevada del Cocuy_sentence_27

As the climate continues to warm, it is likely that these negative impacts on the páramo soils and hydrological characteristics will continue to progress. Sierra Nevada del Cocuy_sentence_28

It has been demonstrated that unsustainable land use, combined with the effects of climate change affect the natural populations of useful endemic plants (mostly medicinal), especially in the western slope of the Sierra Nevada del Cocuy. Sierra Nevada del Cocuy_sentence_29

Geomorphology Sierra Nevada del Cocuy_section_4

The landscapes in the Sierra Nevada del Cocuy are characterized by glacial landforms that were carved and deposited by the advancing and retreating glaciers throughout the Pleistocene Epoch, such as moraines, cirques and glacial valleys. Sierra Nevada del Cocuy_sentence_30

However, the high tectonic activity and continuous uplift in the region has led to widespread bedrock outcroppings (mostly sedimentary rocks) which give the overall shape and elevation of the area, also characterized by faulting and folding of the Cretaceous rocks. Sierra Nevada del Cocuy_sentence_31

Additionally, fluvial and hillslope processes are considerable influences on the landscape as well. Sierra Nevada del Cocuy_sentence_32

Because of this, preservation of glacial landforms is inversely related to their age and, in turn, directly related to their altitude. Sierra Nevada del Cocuy_sentence_33

For example, the steep walls of the glacial U-shaped valleys are made up mostly of quartzitic sandstones and shales, which leads to fragile slope failure and rock falls. Sierra Nevada del Cocuy_sentence_34

These processes lead to the formation of big and widespread colluviums which cover up, or mix with, preexisting moraines or fluvial deposits. Sierra Nevada del Cocuy_sentence_35

Also, as a tropical glacier system, freezing and thawing cycles in the Cocuy glaciers occur on a day-to-night basis, making seasonality of ice advance and retreat non-existent and geomorphological phenomena less straight-forward, which has been hypothesized to be an explanation for the compact aspect of the moraines. Sierra Nevada del Cocuy_sentence_36

Nevertheless, glacial geomorphological features are pervasive such as terminal and lateral moraines, cirques, U-shaped valleys, proglacial, marginal and supraglacial lakes and ice caps. Sierra Nevada del Cocuy_sentence_37

A geological map from Ingeominas shows the distribution of quaternary (glacial) deposits, colluvium and alluvial deposits, as well as bedrock outcroppings. Sierra Nevada del Cocuy_sentence_38

Glacial History and Glacial Retreat Sierra Nevada del Cocuy_section_5

The Sierra Nevada del Cocuy has likely been glaciated for the past ~3 Million Years, however, geological studies have only given light to its most recent history. Sierra Nevada del Cocuy_sentence_39

Palynological records from the region, as well as analyses of glacial moraines have indicated high frequency and amplitude climatic variability in the Eastern Colombian Andes region for at least the last 50000 years. Sierra Nevada del Cocuy_sentence_40

It has also been suggested that glacial advances in the Cocuy region preceded maximum global ice volume during the Last Glacial Maximum (~20ka). Sierra Nevada del Cocuy_sentence_41

Furthermore, less prominent ice advances have been recorded for marine Isotope Stages 1, 2 and 3. Sierra Nevada del Cocuy_sentence_42

The glacier reached its maximum extent during the Antarctic cold reversal (~14.5 – 12.9 ka). Sierra Nevada del Cocuy_sentence_43

More recently, the lowest altitude to have been observed historically occurred around 1850, during the Little Ice Age. Sierra Nevada del Cocuy_sentence_44

Ever since that time, the glacier has been retreating rapidly, at about 1 km per year. Sierra Nevada del Cocuy_sentence_45

The accelerated retreat has been documented by multiple lines of evidence, including satellite or aerial photograph analysis (), historical records and modern-day measurements. Sierra Nevada del Cocuy_sentence_46

Additionally, the equilibrium line elevation (which is an approximation of the mean elevation of the glacier) has been estimated to have decreased from about 4100masl during the last glacial maximum to 4900 masl in present day. Sierra Nevada del Cocuy_sentence_47

With the onset of accelerated warming due to anthropogenic climate change, tropical glaciers such as the ones on the Sierra Nevada del Cocuy are bound to disappear in the next few decades. Sierra Nevada del Cocuy_sentence_48

The Sierra Nevada del Cocuy glaciers, which used to be a single ice body only a few decades ago, had lost an estimated 35-45% of its glacial area in only 15 years (measured in 2006). Sierra Nevada del Cocuy_sentence_49

The entirety of the ice mass from the region has been projected to be completely gone by 2040, although some studies project the disappearance to happen as early as 2025. Sierra Nevada del Cocuy_sentence_50

As climate models become more accurate, it has become clear that these are particularly vulnerable areas to global warming, as the rate of warming of the lower troposphere has been projected to increase with altitude, and be as much as double the temperature increase in areas at or around sea level. Sierra Nevada del Cocuy_sentence_51

Native peoples Sierra Nevada del Cocuy_section_6

Indigenous natives of the region are the U'wa (Tunebos) and their reservation overlaps the area of the park and thus part of the park is dedicated to their farming, grazing, hunting and fishing activities. Sierra Nevada del Cocuy_sentence_52

From 1969 to 1977 in the area of the park and the surrounding area, the Colombian government promoted colonisation from elsewhere in Colombia. Sierra Nevada del Cocuy_sentence_53

This resulted in loss of U'wa lands as well as other settlement enclaves within the park. Sierra Nevada del Cocuy_sentence_54

Climate Sierra Nevada del Cocuy_section_7

Sierra Nevada del Cocuy has a cold alpine tundra climate (ET) with moderate to little rainfall and occasional snowfall year-round. Sierra Nevada del Cocuy_sentence_55

The following climate data is for Alto la Cueva, other places can have higher or lower temperatures with some places covered in snow year-round. Sierra Nevada del Cocuy_sentence_56

Regional geology Sierra Nevada del Cocuy_section_8

Credits to the contents of this page go to the authors of the corresponding Wikipedia page: en.wikipedia.org/wiki/Sierra Nevada del Cocuy.