1. Overview

2. Temperature

3. Name

4. Ecology

5. Geology

6. Climate

7. Islands
    Uros  Amantani  Taquile  Isla del Sol  Isla de la Luna  Suriki 

8. Transport
    History 

9. See also

10. References

11. External links

Lake Titicaca ({{lang-es|Lago Titicaca}}, {{IPA-es|ˈlaɣo titiˈkaka|pron}}; {{lang-qu|Titiqaqa Qucha}}) is a large, deep lake in the Andes on the border of Bolivia and Peru, often called the "highest navigable lake" in the world. By volume of water and by surface area, it is the largest lake in South America.^[3][4][5] Lake Maracaibo has a larger surface area, but it is a tidal bay, not a lake.

Lake Titicaca has a surface elevation of {{convert|3,812|m|abbr=on}}.^[6][7] The "highest navigable lake" claim is generally considered to refer to commercial craft. Numerous smaller bodies of water around the world are at higher elevations.^[8] For many years, the largest vessel afloat on the lake was the 2,200-ton (2,425 U.S. tons), {{convert|79|m|ft|adj=on}} SS Ollanta. Today, the largest vessel is most likely the similarly sized train barge/float Manco Capac, operated by PeruRail.

Other cultures lived on Lake Titicaca prior to the arrival of the Incas. In 2000, a team of international archaeologists found the ruins of an underwater temple, thought to be between 1,000 and 1,500 years old, perhaps built by the Tiwanaku people. The ruins have been measured to be {{cvt|200|by|50|m|abbr=on}}.^[9]

Overview

The lake is located at the northern end of the endorheic Altiplano basin high in the Andes on the border of Peru and Bolivia. The western part of the lake lies within the Puno Region of Peru, and the eastern side is located in the Bolivian La Paz Department.

The lake consists of two nearly separate subbasins connected by the Strait of Tiquina, which is {{convert|800|m|ft|-1|abbr=on}} across at the narrowest point. The larger subbasin, Lago Grande (also called Lago Chucuito), has a mean depth of {{convert|135|m|ft|0|abbr=on}} and a maximum depth of {{convert|284|m|ft|0|abbr=on}}. The smaller subbasin, Wiñaymarka (also called Lago Pequeño, "little lake"), has a mean depth of {{convert|9|m|ft|0|abbr=on}} and a maximum depth of {{convert|40|m|ft|0|abbr=on}}.^[10] The overall average depth of the lake is {{convert|107|m|ft|0|abbr=on}}.^[11]

Five major river systems feed into Lake Titicaca.^[12] In order of their relative flow volumes these are Ramis, Coata, Ilave, Huancané, and Suchez.^[3] More than 20 other smaller streams empty into Titicaca. The lake has 41 islands, some of which are densely populated.

Having only a single season of free circulation, the lake is monomictic,^[13][14] and water passes through Lago Huiñaimarca and flows out the single outlet at the Río Desaguadero,^[15] which then flows south through Bolivia to Lake Poopó. This only accounts for about 10% of the lake's water balance. Evapotranspiration, caused by strong winds and intense sunlight at high altitude, balances the remaining 90% of the water loss. It is nearly a closed lake.^[3][10][16]

Since 2000, Lake Titicaca has experienced constantly receding water levels. Between April and November 2009 alone, the water level dropped by {{convert|81|cm|in|0|abbr=on}}, reaching the lowest level since 1949. This drop is caused by shortened rainy seasons and the melting of glaciers feeding the tributaries of the lake.^[17][18] Water pollution is also an increasing concern because cities in the Titicaca watershed grow, sometimes outpacing solid waste and sewage treatment infrastructure.^[19] According to the Global Nature Fund (GNF), Titicaca's biodiversity is threatened by water pollution and the introduction of new species by humans.^[20] In 2012, the GNF nominated the lake "Threatened Lake of the Year".^[21]

Temperature

The cold sources and winds over the lake give it an average surface temperature of {{convert|10 |to| 14|C|F}}. In the winter (June – September), mixing occurs with the deeper waters, which are always between {{convert|10|and|11|C|F}}.^[22]

Name

Neither the protohistoric nor prehistoric name for Lake Titicaca is known. Given the various Native American groups that occupied the Lake Titicaca region, it likely lacked a single, commonly accepted name in prehistoric times and at the time the Spaniards arrived.^[23]

The terms titi and caca can be translated in multiple ways. In Aymara, titi can be translated as either puma, lead, or a heavy metal. The word caca (kaka) can be translated as white or gray hairs of the head and the term k’ak’a can be translated as either crack or fissure, or alternatively, comb of a bird.^[23] According to Weston La Barre, the Aymara considered in 1948 that the proper name of the lake is titiq’aq’a, which means gray, discolored, lead-colored puma. This phrase refers to the sacred carved rock found on the Island of the Sun.^[24] In addition to names including the term titi and/or caca, Lake Titicaca was also known as Chuquivitu in the 16th century. This name can be loosely translated as lance point. This name survives in modern usage in which the large lake is occasionally referred to as Lago Chucuito.^[23]

Stanish argues that the logical explanation for the origin of the name Titicaca is a corruption of the term thakhsi cala, which is the 15th- to 16th-century name of the sacred rock on the Island of the Sun.^[25] Given the lack of a common name for Lake Titicaca in the 16th century, the Spaniards are thought to have used the name of the site of the most important indigenous shrine in the region, thakhsi cala on the Island of the Sun, as the name for the lake. In time and with usage, this name developed into Titicaca.^[23]

Locally, the lake goes by several names. The small lake to the south is called Huiñamarca. The large lake also is occasionally referred to as Lago Mayor, and the small lake as Lago Menor.^[23] In addition, the southeast quarter of the lake is separate from the main body (connected only by the Strait of Tiquina), and the Bolivians call it Lago Huiñaymarca (also Wiñay Marka, which in Aymara means the Eternal City) and the larger part Lago Chucuito. In Peru, these smaller and larger parts are referred to as Lago Pequeño and Lago Grande, respectively.^[10]

Ecology

Lake Titicaca is home to more than 530 aquatic species.^[27]

The lake holds large populations of water birds and was designated as a Ramsar Site on August 26, 1998. Several threatened species such as the huge Titicaca water frog and the flightless Titicaca grebe are largely or entirely restricted to the lake,^[26][28] and the Titicaca orestias has likely become extinct (last seen in 1938) due to competition and predation by the introduced rainbow trout and the silverside Odontesthes bonariensis.^[29] In addition to the Titicaca orestias, native fish species in the lake's basin are other species of Orestias, and the catfish Trichomycterus dispar, T. rivulatus, and Astroblepus stuebeli (the last species not in the lake itself, but in associated ecosystems).^[49] The many Orestias species in Lake Titicaca differ significantly in both habitat preference^[30] and feeding behavior.^[31] About 90% of the fish species in the basin are endemic,^[32] including 23 species of Orestias that only are found in the lake.^[33] In addition to the threatened Titicaca grebe, some of the birds associated with water at Titicaca are the white-tufted grebe, Puna ibis, Chilean flamingo, Andean gull, Andean lapwing, white-backed stilt, greater yellowlegs, snowy egret, black-crowned night-heron, Andean coot, common gallinule, plumbeous rail, various ducks, wren-like rushbird, many-colored rush-tyrant, and yellow-winged blackbird.^[28]

Titicaca is home to 24 described species of freshwater snails (15 endemics, including several tiny Heleobia spp.)^[27][34] and less than half a dozen bivalves (all in family Sphaeriidae), but in general these are very poorly known and their taxonomy is in need of a review.^[35] The lake also has an endemic species flock of amphipods consisting of 11 Hyalella (an additional Titicaca Hyalella species is nonendemic).^[36]

Reeds and other aquatic vegetation is widespread in Lake Titicaca. Totora reeds grow in water shallower than {{convert|3|m|ft|abbr=on}}, less frequently to {{convert|5.5|m|ft|abbr=on}}, but macrophytes, notably Chara and Potamogeton, occur down to {{convert|10|m|ft|abbr=on}}.^[37] In sheltered shallow waters, such as the harbour of Puno, Azolla, Elodea, Lemna and Myriophyllum are common.^[37]

Geology

The Tinajani Basin, in which Lake Titicaca lies, is an intermontane basin. This basin is a pull-apart basin^[38] created by strike-slip movement along regional faults starting in the late Oligocene and ending in the late Miocene. The initial development of the Tinajani Basin is indicated by volcanic rocks, which accumulated between 27 and 20 million years ago within this basin. They lie upon an angular unconformity which cuts across pre-basin strata. Lacustrine sediments of the Lower Tinajani Formation, which are exposed within the Tinajani Basin, demonstrate the presence of a pre-Quaternary, ancestral Lake Titicaca within it between 18 and 14 million years ago (Mya).^[39] Little is known about the prehistory of Lake Titicaca between 14 Mya and 370,000 BP because the lake sediments dating to this period lie buried beneath the bottom of Lake Titicaca and have not yet been sampled by continuous coring.^[40]

The Lake Titicaca drilling project^[40] recovered a 136-m-long drill core of sediments from the bottom of Lake Titicaca at a depth of {{cvt|235|m|abbr=on}} and at a location just east of Isla del Sol. This core contains a continuous record of lake sedimentation and paleoenvironmental conditions for Lake Titicaca back to about 370,000 BP. For this period of time, Lake Titicaca was typically fresher and had higher lake levels during periods of expanded regional glaciation that corresponded to global glacial periods. During periods of reduced regional glaciation that corresponded to global interglacial periods, Lake Titicaca had typically low lake levels.^[40][41]

Lacustrine sediments and associated terraces provide evidence for the past existence of five major prehistoric lakes that occupied the Tinajani Basin during the Pliocene and Pleistocene. Within the northern Altiplano (Tinajani Basin), these prehistoric lakes were Lake Mataro at an elevation of {{cvt|3950|m|abbr=on}}, Lake Cabana at an elevation of {{cvt|3900|m|abbr=on}}, Lake Ballivián at an elevation of {{cvt|3860|m|abbr=on}}, Lake (North) Minchin at an elevation of {{cvt|3825|m|abbr=on}}, and Lake (North) Tauca at an elevation {{cvt|3815|m|||}}. The age of Lake Mataro is uncertain—it may date back to the Late Pliocene. Lake Cabana possibly dates to the Middle Pleistocene. Lake Ballivián existed between 120,000 and 98,000 BP. Two high lake stands, between 72,000 – 68,000 BP and 44,000 – 34,000 BP, have been discerned for Lake Minchin within the Altiplano. Another ancient lake in the area is Ouki. The high lake levels of Lake Tauca have been dated as having occurred between 18,100 and 14,100 BP.^[42][43][44]

Climate

Lake Titicaca has a borderline subtropical highland/alpine climate with cool to cold temperatures for most of the year. The average annual precipitation is 610 mm (24 in) mostly falling in summer thunderstorms. Winters are dry with very cold nights and mornings and warm afternoons. Below are the average temperatures of the town Juliaca in the northern part of the lake.

Islands

Uros

The "Floating Islands" are small, man-made islands constructed by the Uros (or Uru) people from layers of cut totora, a thick, buoyant reed that grows abundantly in the shallows of Lake Titicaca.^[46] The Uros harvest the reeds that naturally grow on the lake's banks to make the islands by continuously adding reeds to the surface.

According to legend, the Uru people originated in the Amazon and migrated to the area of Lake Titicaca in the pre-Columbian era, where they were oppressed by the local population and were unable to secure land of their own.^[46] They built the reed islands, which could be moved into deep water or to different parts of the lake, as necessary, for greater safety from their hostile neighbors on land.

Golden in color, many of the islands measure about {{convert|50|by|50|ft|order=flip|abbr=on}}, and the largest are roughly half the size of a football field.^[46][47] Each island contains several thatched houses, typically belonging to members of a single extended family.^[46] Some of the islands have watchtowers and other buildings, also constructed of reeds.

Historically, most of the Uros islands were located near the middle of the lake, about {{cvt|9|mi|order=flip|abbr=on}} from the shore; however, in 1986, after a major storm devastated the islands, many Uros rebuilt closer to shore.^[46] {{As of|2011}}, about 1,200 Uros lived on an archipelago of 60 artificial islands,^[46] clustering in the western corner of the lake near Puno, Titicaca's major Peruvian port town.^[47] The islands have become one of Peru's tourist attractions, allowing the Uros to supplement their hunting and fishing by conveying visitors to the islands by motorboat and selling handicrafts.^[46][47]

Amantani

Amantani is another small island on Lake Titicaca populated by Quechua speakers. About 4,000 people live in 10 communities on the roughly circular {{convert|15|km2|sqmi|0|adj=on|abbr=on}} island. Two mountain peaks, called Pachatata (Father Earth) and Pachamama (Mother Earth) and ancient ruins are on the top of both peaks. The hillsides that rise up from the lake are terraced and planted with wheat, potatoes, and vegetables. Most of the small fields are worked by hand. Long stone fences divide the fields, and cattle and sheep graze on the hillsides.

No cars and no hotels are on the island. Since machines are not allowed on the island, all agriculture is done by hand. A few small stores sell basic goods, and a health clinic and six schools are found. Electricity was produced by a generator and provided limited power a few hours each day, but with the rising price of the petroleum, they no longer use the generator. Most families use candles or flashlights powered by batteries or hand cranks. Small solar panels have recently been installed on some homes.

Some of the families on Amantani open their homes to tourists for overnight stays and provide cooked meals, arranged through tour guides. The families who do so are required to have a special room set aside for the tourists and must fit a code by the tourist companies that help them. Guests typically take food staples (cooking oil, rice, etc., but no sugar products, as they have no dental facilities) as a gift or school supplies for the children on the island. They hold nightly traditional dance shows for the tourists where they offer to dress them up in their traditional clothes and participate.

Taquile

Taquile is a hilly island located {{cvt|45|km|abbr=on}} east of Puno. It is narrow and long and was used as a prison during the Spanish Colony and into the 20th century. In 1970, it became property of the Taquile people, who have inhabited the island since then (current population around 2,200). The Taquiean Island is {{cvt|5.5|by|1.6|km|abbr=on}} in size (maximum measurements), with an area of {{cvt|5.72|km2|abbr=on}}. The highest point of the island is {{cvt|4050|m|abbr=on}} above sea level, and the main village is at {{cvt|3950|m|abbr=on}}. Pre-Inca ruins are found on the highest part of the island, and agricultural terraces on hillsides. From the hillsides of Taquile, one has a view over the white snow tops of the Bolivian mountains. The inhabitants, known as Taquileños, are southern Quechua speakers.