Lake Van (Turkish:Van Gölü;Armenian:Վանա լիճ,romanized: Vana lič̣;Kurdish:Gola Wanê[3]) is the largest lake inTurkey.[4][5] It lies in theEastern Anatolia region of Turkey in the provinces ofVan andBitlis, in theArmenian highlands. It is asalinesoda lake, receiving water from many small streams that descend from the surrounding mountains. It is one of the world's fewendorheic lakes (a lake having no outlet) of size greater than 3,000 square kilometres (1,200 sq mi) and has 38% of the country's surface water (including rivers). A volcanic eruptionblocked its original outlet in prehistoric times. It is situated at 1,640 m (5,380 ft) above sea level. Despite the high altitude and winter averages below 0 °C (32 °F),high salinity usually prevents it from freezing; the shallow northern section can freeze, but rarely.[6]
Lake Van is 119 kilometres (74 mi) across at its widest point. It averages 171 metres (561 ft) deep. Its greatest known depth is 451 metres (1,480 ft).[2] The surface lies 1,640 metres (5,380 ft) above sea level and the shore length is 430 kilometres (270 mi). It covers 3,755 km2 (1,450 sq mi) and contains (has a volume of) 607 cubic kilometres (146 cu mi).[2]
The western portion of the lake is deepest, with a large basin deeper than 400 m (1,300 ft) lying northeast ofTatvan and south ofAhlat. The eastern arms of the lake are shallower. The Van-Ahtamar portion shelves gradually, with a maximum depth of about 250 m (820 ft) on its northwest side where it joins the rest of the lake. The Erciş arm is much shallower, mostly less than 50 m (160 ft), with a maximum depth of about 150 m (490 ft).[7][8]
Lake Van is primarily atectonic lake, formed more than 600,000 years ago by the gradual subsidence of a large block of theEarth's crust due to movement on several major faults that run through this portion of Eastern Anatolia. The lake's southern margin demarcates: a metamorphic rock zone of the Bitlis Massif and volcanic strata of theNeogene andQuaternary periods. The deep, western portion of the lake is an antidome basin in a tectonic depression. This was formed bynormal andstrike-slip faulting and thrusting.[10]
The lake's proximity to theKarlıova triple junction has led to molten fluids of the Earth'smantle accumulating in the strata beneath, still driving gradual change.[10] Dominating the lake's northern shore is thestratovolcanoMount Süphan. The broad crater of a second, dormant volcano,Mount Nemrut, is close to the western tip of the lake. There is hydrothermal activity throughout the region.[10]
For much of its history, until thePleistocene, Lake Van has had an outlet towards the southwest (into theMurat River and eventually into theEuphrates river). However, the level of this threshold has varied over time, as the lake has been blocked by successivelava flows fromNemrut volcano westward towards theMuş Plain. This threshold has then been lowered at times by erosion.
Bathymetry
The first acoustic survey of Lake Van was performed in 1974.[7][11]
Kempe and Degens later identified three physiographic provinces comprising the lake:
a lacustrine shelf (27% of the lake) from the shore to a clear gradient change
a steeper lacustrine slope (63%)
a deep, relatively flat basin province (10%) in the western center of the lake.[12]
The deepest part of the lake is the Tatvan basin, which is almost completely bounded by faults.[11]
Prehistoric lake levels
Section of north rim of the Sheikh Ora crater, showing old beach lines, drawn by Felix Oswald, 1906
Land terraces (remnant dry, upper banks from previous shorelines) above the present shore have long been recognized. On a visit in 1898, geologistFelix Oswald noted three raised beaches at 5, 15, and 30 m (15, 50 and 100 ft) above the lake then, as well as recently drowned trees.[13] Research in the past century has identified many similar terraces, and the lake's level has fluctuated significantly during that time. Land terraces (remnant dry, upper banks from previous shorelines) above the present shore have long been recognized. On a visit in 1898, geologistFelix Oswald noted three raised beaches at 5, 15, and 30 m (15, 50 and 100 ft) above the lake then, as well as recently drowned trees.[13] Research in the past century has identified many similar terraces, and the lake's level has fluctuated significantly during that time.
In 1989 and 1990, an international team of geologists led by Stephan Kempe from the University of Hamburg[a] retrieved ten sediment cores from depths up to 446 m (1,463 ft). Although these cores only penetrated the first few meters of sediment, they provided sufficientvarves to give proxy climate data for up to 14,570 yearsBP.[14]
The PALEOVAN project has studied in detail the paleolimnology, paleoclimatology, and sedimentology of Lake Van over the last 600,000 years by using seismic reflection and continuous cores recovered from deep borings.[15] These techniques along with investigation of the chronology and sedimentology of associated onshore terraces have been used to reconstruct past climatic, volcanic, and tectonic activity since the formation of Lake Van about 600,000 years ago when a single pull-apart basin was separated into Van and Mus basins by the eruptions of the Nemrut Volcano which also blocked Lake Van's outlet.[16]
Lake levels (blue line) and paleoclimates of Lake Van, Turkey, for the past 90,000 years. Compiled and created from data of Cukur et al. (2014),[16] Çağatay et al. (2014),[17] and Sarıkaya et al. (2011).[18]
The PALEOVAN project found that the lake level of Lake Van has varied by as much as 600 m (2,000 ft) during the past 600,000 years. During this period of time, five major lowstands of lake level occurred circa 600, 365–340, 290–230, 150–130, and 30–14 ka BP. Between 600 and 230 ka BP, the lake varied dramatically, by hundreds of meters. The occurrence of major lowstands of Lake Van during glacial periods suggest regional paleoclimate, i.e. greatly reduced precipitation, was the dominant cause for the dramatic changes in lake level of Lake Van. However, volcanic and tectonic forcing factors may have contributed to lake level changes as well.[16][17]
Over the last 90,000 years, significant variations in the lake level of Lake Van have been inferred based on the presence of lowstand deltas and onlap sequences in seismic reflection profiles; the analysis of data extracted PALEOVAN cores; and studies of coastal terraces of differing elevations. First, a major lowstand of 120 m (390 ft) below modern lake level occurred between 71 and 59 ka BP as inferred from the presence of lowstand deltas and onlap sequences in seismic reflection profiles. Between 60 and 34 ka BP., the lake level of Lake Van was in general lower than the modern lake level with highstands at 57, 53, 46 and 35 ka BP. About 34 ka BP, a dramatic rise in lake level to about 90 m (300 ft) above the present lake level occurred as indicated by the formation of terraces circa 85 m (279 ft) above present-day lake level and the presence of onlapping seismic onlap sequences. This rapid rise in lake level was likely either the result of increased melt water delivery or the deposition of a large quantities of tephra and lahars (Nemrut Formation) created during a caldera forming eruption of Mount Nemrut. Two terraces dated at 26 to 24.5 and 21 to 20 ka BP reaching 13 m (43 ft) above the present lake level and the occurrence of lowstand deltas and onlap sequences in the seismic reflection profiles indicate high lake levels during the end of Last Glacial period (30 to 15 ka BP). These two terraces were likely deposited during the interstadial events. Between 16 and 15 ka BP, the complete desiccation of Lake Van dropped lake levels to 200 m (660 ft)m below modern levels. By the Bøllinge-Allerød period (14.7 to 12.8 ka BP), lake levels were possibly similar to or little lower than the modern lake level. During the Younger Dryas cold period lake levels dropped to 45 to 95 m (148 to 312 ft) lower than the modern level. The early Holocene was characterized by variable lake levels above and below modern with amplitudes of a few tens of meters. These variations in lake levels during the Holocene are indicated by the presence of early to middle Holocene terraces near river mouths,[16][17]
Recent lake level change
Similar but smaller fluctuations have been seen recently. The level of the lake rose by at least 3 m (9.8 ft) during the 1990s, drowning much agricultural land, and (after a brief period of stability and then retreat) seems to be rising again. The level rose approximately 2 m (6.6 ft) in the 10 years immediately prior to 2004.[1] But in the early 2020s it fell.[19]
Climate
Lake Van is in the highest and largestregion of Turkey, which has a Mediterranean-influencedhumid continental climate. Average temperatures in July are between 22 and 25 °C, and in January between −3 °C and −12 °C. On some cold winter nights the temperature has reached −30 °C.
The lake, particularly on its urban townscape shore, tempers the climate in the city of Van, where the average temperature in July is 22.5 °C, and in January −3.5 °C. The average annual rainfall in the basin ranges from 400 to 700 mm.[20][21]
Prior to 2018, the only fish known to live in thebrackish water of Lake Van wasAlburnus tarichi or Pearl Mullet (Turkish:inci kefali), aCyprinid fish related tochub anddace, which is caught during the spring floods.[22] In May and June, these fish migrate from the lake to less alkaline water, spawning either near the mouths of the rivers feeding the lake or in the rivers themselves. After spawning season it returns to the lake.[23] In 2018, a new species of fish, which is deemed asOxynoemacheilus ercisianus, has been discovered inside amicrobialite.[24][25]
In 1991, researchers reported the discovery of 40 m (130 ft) tallmicrobialites in the lake. These are solid towers on the lake bed formed by coccoidcyanobacteria (Pleurocapsa group), which create mats ofaragonite that combine withcalcite precipitating out of the lake water.[27]
The region hosts the rareVan cat breed of cat, having – among other things – an unusual fascination with water. The lake is mainly surrounded by fruit orchards andgrain fields, interspersed by some non-agricultural trees.
According to legend, the lake hosts the mysteriousLake Van Monster that lurks below the surface, 30-to-40 ft (9-to-12 m) long with brown scaly skin, an elongated reptilian head and flippers. Apart from some inconclusive amateur photographs and videos, there has never been any evidence of it. The claimed profile resembles an extinctmosasaurus orbasilosaurus.
History
1910 ethnographical map of Lake Van; dark green representsArmenians.
Tushpa, the capital ofUrartu, near the shores, on the site of what became medieval Van's castle, west of present-dayVan city.[28] The ruins of the medieval city of Van are still visible below the southern slopes of the rock on whichVan Castle stands.
In 2017, archaeologists fromVan Yüzüncü Yil University and a team of independent divers who were exploring Lake Van reported the discovery of a large underwater fortress spanning roughly one kilometer.[29] The team estimates that this fortress was constructed during the Urartian period, based on their visual assessments. The archaeologists believe that the fortress, along with other parts of the ancient city that surrounded it at the time, had slowly become submerged over the millennia by the gradually rising lake.[30]
Along withLake Sevan in today'sArmenia andLake Urmia in today'sIran, Van was one of the three great lakes of the Armenian Kingdom, referred to asthe seas ofArmenia (in ancient Assyrian sources: "tâmtu ša mât Nairi" (Upper Sea ofNairi), the Lower Sea beingLake Urmia).[31] Over time, the lake was known by various Armenian names, includingArmenian:Վանա լիճ (Lake of Van), Վանա ծով (Sea of Van), Արճեշի ծով (Sea of Arčeš), Բզնունեաց ծով (Sea of Bznunik),[32] Ռշտունեաց ծով (Sea of Rshtunik),[32] and Տոսպայ լիճ (Lake of Tosp).
Eastern Roman Empire
By the 11th century the lake was on the border between theEastern Roman Empire, with its capital atConstantinople, and theTurko-Persian Seljuk Empire, with its capital atIsfahan. In the uneasy peace between the two empires, local Armenian-Byzantine landowners employedTurcomangazis and Byzantineakritai for protection. The Greek-speaking Byzantines called the lakeThospitis limne (Medieval Greek:Θωσπῖτις λίμνη).
In the second half of the 11th century EmperorRomanus IV Diogenes launched a campaign to re-conquer Armenia and head off growing Seljuk control. Diogenes and his large army crossed theEuphrates and confronted a much smaller Seljuk force led byAlp Arslan at theBattle of Manzikert, north of Lake Van on 26 August 1071. Despite their greater numbers, the cumbersome Byzantine force was defeated by the more mobile Turkish horsemen and Diogenes was captured.
Seljuk Empire
An early 20th century picture of the 10th century Armenian monastery ofNarekavank, which once stood near the southeastern shore of the lakeView of the lake from aboard thetrain ferryVan of theTurkish State Railways in 1987. In December 2015, the new generation of train ferries, the largest of their kind in Turkey, entered service in Lake Van.[33]
Alp Arslan divided the conquered eastern portions of the Byzantine empire among his Turcoman generals, with each ruled as a hereditarybeylik, under overall sovereignty of theSeljuq Empire. Alp Arslan gave the region around Lake Van to his commanderSökmen el-Kutbî, who set up his capital at Ahlat on the western side of the lake. The dynasty ofShah-Armens, also known asSökmenler, ruled this area from 1085 to 1192.
Following the disintegration of the Seljuq-ruledSultanate of Rum, Lake Van and its surroundings were conquered by theIlkhanate Mongols, and later switched hands between the Ottoman Empire andSafavid Iran until SultanSelim I took control for good.
Reports of theLake Van Monster surfaced in the late 1800s and gained popularity. A news article was published bySaadet Gazetesi issue number 1323, dated 28 Shaban 1306Hijri year, corresponding to 29 April 1889 during the reign of SultanAbdul Hamid II.[34]
The Ahlatshahs left a large number of historicheadstones in and around the town ofAhlat. Local administrators are currently trying to have the tombstones included inUNESCO'sWorld Heritage List, where they are currently listed tentatively.[35][36]
Transportation
The railway connecting Turkey andIran was built in the 1970s, sponsored byCENTO. It uses atrain ferry (ferry for decanted passengers) across between the citiesTatvan andVan, rather than building tracks around rugged terrain. This limits passenger capacity. In May 2008, talks started between Turkey and Iran to replace the ferry with a double-track electrified railway.[37]
In December 2015, the new generation oftrain ferries operated by theTurkish State Railways, the largest of their kind in Turkey, entered service in Lake Van.[33]
The four main islands in Lake Van areAdır,Akdamar,Çarpanak, andKuş islands. Adır Island is the biggest Island in Lake Van.
Each island has Armenian religious structures: Lim Monastery (Adır Island),Holy Cross Cathedral (Akdamar Island),Ktuts Monastery (Çarpanak Island) and a small monastery on Kuş Island.
Çağatay, M.N.; Öğretmen, N.; Damcı, E.; Stockhecke, M.; Sancar, Ü.; Eriş, K.K.; Özeren, S. (2014), "Lake level and climate records of the last 90 ka from the Northern Basin of Lake Van, eastern Turkey",Quaternary Science Reviews,104 (2014):97–116,doi:10.1016/j.quascirev.2014.09.027
Cottrell, Leonard (1960),The Concise Encyclopædia of Archaeology
Danulat, Eva; Kempe, Stephan (February 1992), "Nitrogenous waste excretion and accumulation of urea and ammonia inChalcalburnus tarichi (Cyprinidae), endemic to the extremely alkaline Lake Van (Eastern Turkey)",Fish Physiology and Biochemistry,9 (5–6):377–386,Bibcode:1992FPBio...9..377D,doi:10.1007/BF02274218,PMID24213814,S2CID7471283
Cukur, D.; Krastel, S.; Schmincke, H.U.; Sumita, M.; Çağatay, MN.; Meydan, A.F.; Damcı, E.; Stockhecke, M. (2014), "Seismic stratigraphy of lake Van, eastern Turkey",Quaternary Science Reviews,104 (2014):63–84,doi:10.1016/j.quascirev.2014.07.016
Kempe, S.; Degens, E.T. (1978), "Lake Van varve record: the past 10,420 years", in Degens, E.T.; Kurtman, F. (eds.),Geology of Lake Van, Ankara: MTA Press, pp. 56–63
Kempe, S.; Kazmierczak, J.; Landmann, G.; Konuk, T.; Reimer, A.; Lipp, A. (14 February 1991), "Largest known microbialites discovered in Lake Van, Turkey",Nature,349 (6310):605–608,Bibcode:1991Natur.349..605K,doi:10.1038/349605a0,S2CID4240438
Landmann, Günter; Reimera, Andreas; Lemcke, Gerry; Kempe, Stephan (June 1996), "Dating Late Glacial abrupt climate changes in the 14,570 yr long continuous varve record of Lake Van, Turkey",Palaeogeography, Palaeoclimatology, Palaeoecology,122 (1–4),Elsevier Science B.V.:107–118,Bibcode:1996PPP...122..107L,doi:10.1016/0031-0182(95)00101-8
Litt, T.; Anselmetti, F.S.; Baumgarten, H.; Beer, J.; Cukur, D.; Damcı, E.; Glombitza, C.; Others (2014), "500,000 Years of environmental history in eastern Anatolia: the PALEOVAN drilling project",Scientific Drilling,14:18–29
Sarı, Mustafa (2008), "Threatened fishes of the world: Chalcalburnus tarichi (Pallas 1811) (Cyprinidae) living in the highly alkaline Lake Van, Turkey",Environmental Biology of Fishes,81 (1), Springer Netherlands:21–23,doi:10.1007/s10641-006-9154-9,S2CID36074817
Sarıkaya, M.A.; Çiner, A.; Zreda, A. (2011), "Quaternary glaciations of Turkey",Developments in Quaternary Sciences,15 (2011):393–403,doi:10.1016/B978-0-444-53447-7.00030-1
Tomonaga, Yama; Brennwald, Matthias S.; Kipfer, Rolf (2011), "Spatial distribution and flux of terrigenic He dissolved in the sediment pore water of Lake Van (Turkey)",Geochimica et Cosmochimica Acta,75 (10):2848–2864,Bibcode:2011GeCoA..75.2848T,doi:10.1016/j.gca.2011.02.038
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