Porewater salinity reveals past lake-level changes in Lake Van, the Earth's largest soda lake.
In closed-basin lakes, sediment porewater salinity can potentially be used as a conservative tracer to reconstruct past fluctuations in lake level. However, until now, porewater salinity profiles did not allow quantitative estimates of past lake-level changes because, in contrast to the oceans, significant salinity changes (e.g., local concentration minima and maxima) had never been observed in lacustrine sediments. Here we show that the salinity measured in the sediment pore water of Lake Van (Turkey) allows straightforward reconstruction of two major transgressions and a major regression that occurred during the last 250 ka. We observed strong changes in the vertical salinity profiles of the pore water of the uppermost 100 m of the sediments in Lake Van. As the salinity balance of Lake Van is almost at steady-state, these salinity changes indicate major lake-level changes in the past. In line with previous studies on lake terraces and with seismic and sedimentological surveys, we identify two major transgressions of up to +105 m with respect to the current lake level at about 135 ka BP and 248 ka BP starting at the onset of the two previous interglacials (MIS5e and MIS7), and a major regression of about -200 m at about 30 ka BP during the last ice age.
Eawag, Swiss Federal Institute of Aquatic Science and Technology, Department of Water Resources and DrinkingWater, Überlandstrasse 133, 8600, Dübendorf, Switzerland. yama@tomonaga.ch.|Atmosphere and Ocean Research Institute, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba, 277-8564, Japan. yama@tomonaga.ch.|Institute of Geological Sciences, University of Bern, Baltzerstrasse 1+3, 3012, Bern, Switzerland. yama@tomonaga.ch.
Yama
http://orcid.org/0000-0003-2871-8826
Y
Tomonaga
Eawag, Swiss Federal Institute of Aquatic Science and Technology, Department of Water Resources and DrinkingWater, Überlandstrasse 133, 8600, Dübendorf, Switzerland.
Matthias S
MS
Brennwald
Eawag, Swiss Federal Institute of Aquatic Science and Technology, Department of Water Resources and DrinkingWater, Überlandstrasse 133, 8600, Dübendorf, Switzerland.
David M
DM
Livingstone
Eawag, Swiss Federal Institute of Aquatic Science and Technology, Department of Water Resources and DrinkingWater, Überlandstrasse 133, 8600, Dübendorf, Switzerland.|Geological Institute, Swiss Federal Institute of Technology (ETH), 8092, Zürich, Switzerland.|Ruhr-University Bochum, Universitätstrasse 150, 44801, Bochum, Germany.
Olga
O
Kwiecien
Eawag, Swiss Federal Institute of Aquatic Science and Technology, Department Surface Water Research and Management, Seestrasse 79, 6047, Kastanienbaum, Switzerland.|Institute of Biogeochemistry and Pollutant Dynamics, Swiss Federal Institute of Technology (ETH), 8092, Zürich, Switzerland.
Marie-Ève
MÈ
Randlett
Institute of Biogeochemistry and Pollutant Dynamics, Swiss Federal Institute of Technology (ETH), 8092, Zürich, Switzerland.|Eawag, Swiss Federal Institute of Aquatic Science and Technology, Department Surface Water Research and Management, Überlandstrasse 133, 8600, Dübendorf, Switzerland.
Mona
M
Stockhecke
Eawag, Swiss Federal Institute of Aquatic Science and Technology, Department Surface Water Research and Management, Überlandstrasse 133, 8600, Dübendorf, Switzerland.
Katie
K
Unwin
Institute of Geological Sciences, University of Bern, Baltzerstrasse 1+3, 3012, Bern, Switzerland.|Eawag, Swiss Federal Institute of Aquatic Science and Technology, Department Surface Water Research and Management, Überlandstrasse 133, 8600, Dübendorf, Switzerland.|Oeschger Centre for Climate Change Research, University of Bern, Falkenplatz 16, 3012, Bern, Switzerland.
Flavio S
FS
Anselmetti
Eawag, Swiss Federal Institute of Aquatic Science and Technology, Department Surface Water Research and Management, Überlandstrasse 133, 8600, Dübendorf, Switzerland.
Jürg
J
Beer
Geological Institute, Swiss Federal Institute of Technology (ETH), 8092, Zürich, Switzerland.
Gerald H
GH
Haug
Eawag, Swiss Federal Institute of Aquatic Science and Technology, Department Surface Water Research and Management, Seestrasse 79, 6047, Kastanienbaum, Switzerland.|Institute of Biogeochemistry and Pollutant Dynamics, Swiss Federal Institute of Technology (ETH), 8092, Zürich, Switzerland.
Carsten J
CJ
Schubert
Eawag, Swiss Federal Institute of Aquatic Science and Technology, Department Surface Water Research and Management, Überlandstrasse 133, 8600, Dübendorf, Switzerland.
Mike
M
Sturm
Eawag, Swiss Federal Institute of Aquatic Science and Technology, Department of Water Resources and DrinkingWater, Überlandstrasse 133, 8600, Dübendorf, Switzerland.|Institute of Biogeochemistry and Pollutant Dynamics, Swiss Federal Institute of Technology (ETH), 8092, Zürich, Switzerland.|Institute of Geochemistry and Petrology, Swiss Federal Institute of Technology (ETH), 8092, Zurich, Switzerland.
Rolf
R
Kipfer