Editing Lake Van (section)

===Prehistoric lake levels===
[[File:Old beach lines shown on section of north rim of Sheikh Ora volcano near Tatvan Felix Oswald Geology of Armenia 1906 p103f-b (cropped).png|thumb|Section of north rim of the Sheikh Ora crater, showing old beach lines, drawn by Felix Oswald, 1906]]
[[File:Turkey, Van Lake 10.jpg|thumb|left|200px|View of Lake Van from the air.]]
Land terraces (remnant dry, upper banks from previous shorelines) above the present shore have long been recognized. On a visit in 1898, geologist [[Felix Oswald (archaeologist)|Felix Oswald]] noted three raised beaches at 15, 50 and 100 feet (5, 15 and 30 meters) above the lake then, as well as recently drowned trees.{{sfn|Oswald|1906|pp=102–103}} Research in the past century has identified many similar terraces, and the lake's level has fluctuated significantly during that time.

As the lake has no outlet, the level over recent millennia rests on inflow and evaporation.

The water level has vacillated greatly. Investigation by a team including Degens in the early 1980s determined that the highest lake levels ({{convert|72|m}} above the current height) had been during the last ice age, about 18,000 years ago. Approximately 9,500 years ago there was a dramatic drop to more than {{convert|300|m}} below the present level. This was followed by an equally-dramatic rise around 6,500 years ago.{{sfn|Degens|Wong|Kempe|Kurtman|1984}}

As a deep lake with no outlet, Lake Van has accumulated great amounts of sediment washed in from surrounding plains and valleys, and occasionally deposited as ash from eruptions of nearby volcanoes.
This layer of sediment is estimated to be up to {{convert|400|m}} thick in places, and has attracted climatologists and vulcanologists interested in drilling cores to examine the layered sediments.

[[Image:Çadır Dağı seen from the island of Akdamar in lake Van.jpg|right|thumb|The dormant volcano [[Mount Artos|Mount Çadır]] viewed from [[Akdamar Island]]]]
In 1989 and 1990, an international team of geologists led by Stephan Kempe from the University of Hamburg{{efn|Later Professor at the Technische Universität Darmstadt}} retrieved ten sediment cores from depths up to {{convert|446|m|ft|abbr=on}}. Although these cores only penetrated the first few meters of sediment, they provided sufficient [[varves]] to give proxy climate data for up to 14,570 years [[Before Present|BP]].{{sfn|Landmann|Reimera|Lemcke|Kempe|1996}}

A team of scientists headed by palaeontologist Professor Thomas Litt at the [[University of Bonn]] has applied for funding from the [[International Continental Scientific Drilling Program]] (ICDP) for an akin deeper-drilling project. This expects to find it "stores the climate history of the last 800,000 years—an incomparable treasure house of data which we want to tap for at least the last 500,000 years."{{sfn|University of Bonn|2007}} A test drilling in 2004 detected evidence of 15 volcanic eruptions in the past 20,000 years.