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The Salt Flats in Uyuni, Bolivia

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Salar de Uyuni Background

Salar de Uyuni comprises over 10,000km² in the

Potosi region. The salt is over 10 meters thick in the centre. In the dry season, the salt plains are a com-pletely flat expanse of dry salt, but in the wet season,

it is covered with a thin sheet of water that is still

drivable.The standard tour heads south toward the south-

west corner of Bolivia, by many fluorescent-coloured lakes that are created from

a collection of different minerals from runoff from

the surrounding moun-tains.

Tour Back-ground

This article outlines the “standard” tour. The tour is conducted in 4x4 vehicles (usually Toyota

Landcruisers) with 6 or 7 people, with the driver

often times cooking. Most 3- and 4- day tours have the same itinerary for the first 2 1/2 days, a day on the salt plains, then head-ing south to the southwest corner of Bolivia, and then

splitting off from there. The specific sites that are seen can be dependent on the tour, but group input

can define which sites are visited and how much

time will be spent at each.Accommodation is usually provided in basic refuges and the weather can be very cold, but it is well worth it for the amazing scenery. Avoid tours that offer a night in one of the

salt hotels - they are il-legal as, not being part of the water grid, they pol-

lute the environment.

Formation, ge-ology and cli-

mate

Salar de Uyuni is part of the Altiplano of Bolivia in South America. The Al-tiplano is a high plateau, which was formed during uplift of the Andes moun-tains. The plateau includes fresh and saltwater lakes as well as salt flats and is surrounded by mountains with no drainage outlets.

The geological history of the Salar is associated

with a sequential transfor-mation between several

vast lakes. Some 30,000 to 42,000 years ago, the area was part of a giant prehis-toric lake, Lake Minchin.

Its age was estimated from radiocarbon dating of

shells from outcropping sediments and carbonate reefs and varies between reported studies. Lake

Minchin (named after Juan B. Minchin of Oruro) later transformed into paleolake Tauca having a maximal depth of 140 meters (460 ft), and an estimated age

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of 13,000 to 18,000 or 14,900 to 26,100 years,

depending on the source. The youngest prehistoric lake was Coipasa, which was radiocarbon dated to 11,500 to 13,400 years ago. When it dried, it

left behind two modern lakes, Poopó Lake and Uru Uru Lake, and two major salt deserts, Salar

de Coipasa and the larger Salar de Uyuni. Salar de

Uyuni spreads over 10,582 square kilometers (4,086 sq mi), which is roughly 100 times the size of the Bonneville Salt Flats in the United States. Lake

Poopó is a neighbor of the much larger Lake Titicaca.

During the wet season, Titicaca overflows and discharges into Poopó,

which, in turn, floods Sal-ar De Coipasa and Salar

de Uyuni.

Lacustrine mud that is interbedded with salt and

saturated with brine under-lies the surface of Salar de Uyuni. The brine is a satu-rated solution of sodium chloride, lithium chloride and magnesium chloride

in water. It is covered with a solid salt crust varying in thickness between tens of centimeters and a few meters. The center of the Salar contains a few “is-

lands”, the remains of the tops of ancient volcanoes submerged during the era of Lake Minchin. They in-clude unusual and fragile coral-like structures and

deposits that often consist of fossils and algae.

The area has a relatively stable average temperature with a peak at 21 °C (70

°F) in November to Janu-ary and a low of 13 °C (55 °F) in June. The nights are cold all through the year,

with temperatures between −9 and 5 °C (16 and 41 °F). The relative humid-ity is rather low and con-stant throughout the year at 30 to 45%. The rainfall is also low at 1 to 3 mil-limeters (0.039 to 0.118 in) per month between

April and November, but it may increase up to 70 millimeters (2.8 in) in

January. However, except for January, even in the

rainy season the number of rainy days is fewer than

5 per month.

Economic influ-ence

The Salar contains large amounts of sodium,

potassium, lithium and magnesium (all in the

chloride forms of NaCl, KCl, LiCl and MgCl2,

respectively), as well as borax. Of those, lithium is arguably most impor-tant as it is a vital com-ponent of many electric

batteries. With esti-mated 9,000,000 tonnes (8,900,000 long tons; 9,900,000 short tons),

Bolivia holds about 43% of the world’s lithium reserves; most of those are located in the Salar

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de Uyuni.

Lithium is concentrated in the brine under the

salt crust at a relatively high concentration of about 0.3%. It is also

present in the top layers of the porous halite body

lying under the brine; however the liquid brine

is easier to extract, by boring into the crust and pumping out the brine. The brine distribution has been monitored by

the Landsat satellite and confirmed in ground

drilling tests. Following those findings, an Amer-ican-based international corporation has invested $137 million to develop lithium extraction. How-ever, lithium extraction in the 1980s and 1990s by foreign companies met strong opposition

of the local community. Despite their poverty,

locals believed that the money infused by min-

ing would not reach them.

There is currently no mining plant at the site, and the Bolivian gov-ernment does not want to allow exploitation by

foreign corporations. In-stead, it intends to build its own pilot plant with a modest annual pro-

duction of 1,200 tonnes (1,200 long tons; 1,300 short tons) of lithium and to increase it to

30,000 tonnes (30,000 long tons; 33,000 short

tons) by 2012.

Salar de Uyuni is es-timated to contain 10 billion tonnes (9.8 bil-

lion LT; 11 billion ST) of salt, of which less than 25,000 tonnes (25,000 long tons; 28,000 short tons) is extracted annu-ally. All miners working

in the Salar belong to Colchani’s cooperative.

Because of its location, large area and flatness, the Salar is a major car transport route across

the Bolivian Altiplano, except when seasonally

covered with water.

Name

Salar is salt flat in Span-ish. Uyuni originates from the Aymara language and means a pen (enclosure); Uyuni is also the name

of a town that serves as a gateway for tourists visit-ing the Salar. Thus Salar de Uyuni can be loosely translated as a salt flat

with enclosures, the latter possibly referring to the “islands” of the Salar; or as “salt flat at Uyuni (the town named ‘pen for ani-

mals’)”.

Aymara legend tells that the mountains Tunupa,

Kusku and Kusina, which surround the Salar, were

giant people. Tunupa mar-ried Kusku, but Kusku ran away from her with

Kusina. Grieving Tunupa started to cry while breast-feeding her son. Her tears

mixed with milk and formed the Salar. Many

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locals consider the Tunupa an important deity and

say that the place should be called Salar de Tunupa rather than Salar de Uyuni.

Flora and fauna

The Salar is virtually devoid of any wildlife or vegetation. The

latter is dominated by giant cacti

(Echinopsis ataca-mensis pasacana, Echinopsis tari-

jensis, etc.). They grow at a rate of about 1 centime-ter (0.39 in) per year to a height of about 12 me-

ters (39 ft). Other shrubs include

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Pilaya, which is used by locals to cure catarrh, and Thola (Baccharis dracun-culifolia), which is burned as a fuel. Also present are quinoa plants and quenua

bushes.

Every November, Salar de Uyuni is the breeding ground for three species of pink South American flamingo: the Chilean,

Andean and rare James’s Flamingos, their color presumably originating from feeding on pink

algae. There are about 80 other bird species pres-

ent, including the Horned Coot, Andean Goose and Andean Hillstar. Andean fox (culpeo) is a repre-

sentative animal, and the “islands” of Salar (in par-ticular Incahuasi island)

host colonies of rabbit-like

The Salar is virtually devoid of any wildlife or vegetation. The latter is dominated by giant cacti (Echinopsis atacamen-

sis pasacana, Echinopsis tarijensis, etc.). They grow at a rate of about 1 centi-

meter (0.39 in) per year to

The Salar is virtually devoid of any wildlife or vegetation. The latter is dominated by giant cacti (Echinopsis atacamen-

sis pasacana, Echinopsis tarijensis, etc.). They grow

at a rate of about 1 centi-meter (0.39 in) per year to a height of about 12 me-ters (39 ft). Other shrubs include Pilaya, which is

used by locals to cure ca-tarrh, and Thola (Baccha-ris dracunculifolia), which is burned as a fuel. Also

present are quinoa plants and

quenua bushes.

Every November,

Salar de Uyuni is

the breed-ing ground

for three species of pink South American flamingo: the Chilean, Andean and rare James’s Flamingos, their color presumably

originating from feeding

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on pink algae. There are about 80 other bird spe-cies present, including

the Horned Coot, Andean Goose and Andean Hill-star. Andean fox (culpeo) is a representative animal, and the “islands” of Salar (in particular Incahuasi island) host colonies of rabbit-like viscachas.

TourismHotels

Salar de Uyuni attracts tourists from around the world. As it is located far from the cities, a number of hotels have been built

in the area. Due to lack

of con-ventional construc-

tion materi-als, many of them

are almost entirely

(walls, roof, furniture) built with salt blocks cut from the Salar. The first such hotel

was erected in 1993–1995 in the middle

of the salt flat, and soon

became a poular tourist destina-tion. However,

its location in the center of a desert

caused sanita-tion problems, as most waste had to

be collected manually. Mismanagement caused serious environmental

pollution and the hotel had to be dismantled in 2002. New salt hotels were built near the periphery of the Salar, closer to roads, in

full compliance with envi-ronmental rules.

Train cemetery

One major tourist attrac-tion is an antique train cemetery. It is 3 kilo-

meters (1.9 mi) outside Uyuni and is connected to it by the old train tracks. The town served in the

past as a distribution hub for the trains carrying

minerals en route to Pa-cific Ocean ports. The rail lines were built by British

engineers arriving near the end of the 19th cen-

tury and formed a sizeable community in Uyuni. The

engineers were invited by the British-sponsored Antofagasta and Bolivia

Railway Companies, now Ferrocarril de Antofagasta

a Bolivia. The rail con-struction started in 1888

and ended in 1892. It was

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encouraged by Bolivian President Aniceto Arce, who believed Bolivia

would flourish with a good transport system, but it

was also constantly sabo-taged by the local Aymara indigenous Indians who

saw it as an intrusion into their lives. The trains were mostly used by the mining companies. In the 1940s, the mining industry col-lapsed, partly because of mineral depletion. Many trains were abandoned,

producing the train cem-etery. There are proposals to build a museum from

the cemetery.

Satellite cali-bration

Salt flats are ideal for cali-brating the distance mea-surement equipment of

satellites because they are large, stable surfaces with

strong reflection, simi-lar to that of ice sheets.

As the largest salt flat on Earth, Salar de Uyuni is

especially suitable for this purpose. In the low-rain

period from April to No-vember, due to the absence

of industry and its high elevation, the skies above Salar de Uyuni are very clear, and the air is dry

(relative humidity is about 30%; rainfall is roughly 1 millimetre or 0.039 inches per month). It has a stable surface which is smoothed

by seasonal flooding (water dissolves the salt surface and thus keeps it leveled). As a result, the variation in the surface

elevation over the 10,582-square-kilometer (4,086 sq mi) area of Salar de Uyuni

is less than 1 meter (3 ft 3 in), and there are few

square kilometers on Earth that are as flat. The surface reflectivity (albedo) for ul-traviolet light is relatively

high at 0.69 and shows variations of only a few

percent during the daytime. The combi-nation of all

these features makes Salar

de Uyuni about five

times better for satel-lite calibration than the surface of an ocean. Us-ing Salar de Uyuni as the target, ICESat has already achieved the short-term elevation measurement

accuracy of below 2 centi-meters (0.79 in).

With the use of modern GPS technology, it can now be proved that the Salar de Uyuni is not

perfectly flat. New mea-surements revealed pre-viously missed features resembling ridges, hills,

and valleys only millime-ters in height. They origi-nate from the variation in material density, and thus

the gravitational force, beneath the Salar’s sedi-ments. Just as the ocean surface rises over denser

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Thank you

Sin Hyeeun52200114046