Evaluating Sedimentary Geochemical Lake-Level Tracers in Walker Lake, Nevada, Over the Last 200 Years

Authors

Fasong Yuan, Cleveland State UniversityFollow
Braddock K. Linsley, University at Albany-State University of New York
Stephen S. Howe, University at Albany-State University of New York

Document Type

Article

Publication Date

7-2006

Publication Title

Journal of Paleolimnology

Disciplines

Biology

Abstract

Walker Lake, a hydrologically closed, saline, alkaline lake located along the western margin of the Great Basin of western United States, has experienced a 77% reduction in volume and commitment drop in lake level as a result of anthropogenic perturbations and climatic fluctuations over the last century. The history of lake-level change in Walker Lake has been recorded instrumentally since 1860. A high-resolution multi-proxy sediment core record from Walker Lake has been generated through analysis of total inorganic carbon (TIC), total organic carbon (TOC), and oxygen and carbon isotope ratios (δ¹⁸O and δ¹³ C) of both downcore bulk TIC and ostracods over the last 200 yr. This allows us to examine how these sediment indices respond to actual changes in this lake’s hydrologic balance at interannual to decadal timescales. In Walker Lake sediments, changes in %TIC, %TOC, and δ¹³C and δ¹⁸O of TIC and ostracods are all associated to varying degrees with changes in the lake’s hydrologic balance, with δ¹⁸O of the TIC fraction (δ¹⁸O_TIC) being the most highly correlated and the most effective hydrologic indicator in this closed-basin lake. The δ¹⁸O_TIC record from Walker Lake nearly parallels the instrumental lake-level record back to 1860. However, comparison with sporadic lake-water δ¹⁸O and dissolved inorganic carbon δ¹³C (δ¹³C_DIC) results spanning the last several decades suggests that the isotopic values of downcore carbonate sediments may not be readily translated into absolute or even relative values of corresponding lake-water δ¹⁸O and δ¹³C_DIC. Changes in the lake’s hydrologic balance usually lead to changes in isotopic composition of lake waters and downcore sediments, but not all the variations in downcore isotopic composition are necessarily caused by hydrologic changes.

DOI

10.1007/s10933-006-0004-8

Version

Postprint

Publisher's Statement

The final publication is available at Springer via http://dx.doi.org/10.1007/s10933-006-0004-8

Recommended Citation

Yuan F, Linsley BK, Howe SS. 2006. Evaluating sedimentary geochemical lake-level tracers in Walker Lake, Nevada, over the last 200 years. J Paleolimnol. 36(1):37-54.

Volume

36

Issue

1