TY - JOUR
T1 - Isotopic evolution of saline lakes in the low-latitude and polar regions
AU - Horita, Juske
N1 - Funding Information:
Acknowledgments Thanks are due to Berry Lyons, and an anonymous reviewer for their comments. Research was sponsored by the Division of Chemical Sciences, Geosciences, and Biosciences, Office of Basic Energy Sciences, U.S. Department of Energy under contract DE-AC05-00OR22725, Oak Ridge National Laboratory, managed by UT-Battle, LLC.
PY - 2009
Y1 - 2009
N2 - Isotopic fractionations associated with two primary processes (evaporation and freezing of water) are discussed, which are responsible for the formation and evolution of saline lakes in deserts from both low-latitude and the Polar regions. In an evaporative system, atmospheric parameters (humidity and isotopic composition of water vapor) have strong influence on the isotopic behavior of saline lakes, and in a freezing system, salinity build-up largely controls the extent of freezing and associated isotope fractionation. In both systems, salinity has a direct impact on the isotopic evolution of saline lakes. It is proposed that a steady-state "terminal lake" model with short-term hydrologic and environmental perturbations can serve as a useful framework for investigating both evaporative and freezing processes of perennial saline lakes. Through re-assessment of own work and literature data for saline lakes, it was demonstrated that effective uses of the isotope activity compositions of brines and salinity-chemistry data could reveal dynamic changes and evolution in the isotopic compositions of saline lakes in response to hydrologic and environmental changes. The residence time of isotopic water molecules in lakes determines the nature of responses in the isotopic compositions following perturbations in the water and isotope balances (e.g., dilution by inflow, water deficit by increased evaporation, and/or reduction in inflow). The isotopic profiles of some saline lakes from the Polar regions show that they switched the two contrasting modes of operation between evaporative and freezing systems, in response to climate and hydrological changes in the past.
AB - Isotopic fractionations associated with two primary processes (evaporation and freezing of water) are discussed, which are responsible for the formation and evolution of saline lakes in deserts from both low-latitude and the Polar regions. In an evaporative system, atmospheric parameters (humidity and isotopic composition of water vapor) have strong influence on the isotopic behavior of saline lakes, and in a freezing system, salinity build-up largely controls the extent of freezing and associated isotope fractionation. In both systems, salinity has a direct impact on the isotopic evolution of saline lakes. It is proposed that a steady-state "terminal lake" model with short-term hydrologic and environmental perturbations can serve as a useful framework for investigating both evaporative and freezing processes of perennial saline lakes. Through re-assessment of own work and literature data for saline lakes, it was demonstrated that effective uses of the isotope activity compositions of brines and salinity-chemistry data could reveal dynamic changes and evolution in the isotopic compositions of saline lakes in response to hydrologic and environmental changes. The residence time of isotopic water molecules in lakes determines the nature of responses in the isotopic compositions following perturbations in the water and isotope balances (e.g., dilution by inflow, water deficit by increased evaporation, and/or reduction in inflow). The isotopic profiles of some saline lakes from the Polar regions show that they switched the two contrasting modes of operation between evaporative and freezing systems, in response to climate and hydrological changes in the past.
KW - Antarctica
KW - Arctic
KW - Evaporation
KW - Freezing
KW - Isotopic compositions
KW - Low-latitude
KW - Perturbations
KW - Saline lakes
KW - Steady-state
UR - http://www.scopus.com/inward/record.url?scp=64249116100&partnerID=8YFLogxK
U2 - 10.1007/s10498-008-9050-3
DO - 10.1007/s10498-008-9050-3
M3 - Article
AN - SCOPUS:64249116100
VL - 15
SP - 43
EP - 69
JO - Aquatic Geochemistry
JF - Aquatic Geochemistry
SN - 1380-6165
IS - 1-2
ER -