• Harvey Thorleifson, Chair
    Minnesota Geological Survey
  • Carrie Jennings, Vice Chair
    Minnesota Geological Survey
  • David Bush, Technical Program Chair
    University of West Georgia
  • Jim Miller, Field Trip Chair
    University of Minnesota Duluth
  • Curtis M. Hudak, Sponsorship Chair
    Foth Infrastructure & Environment, LLC


Paper No. 12
Presentation Time: 5:00 PM


ALI, Guleed AH, Department of Earth and Environmental Sciences and Lamont-Doherty Earth Observatory, Columbia University, New York, NY 10964, HEMMING, Sidney, Department of Earth and Environmental Sciences and Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY 10964, WANG, Xianfeng, Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY 10964 and ZIMMERMAN, Susan H., Center for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory, Livermore, CA 94550,

Significant geomorphic, chronologic, and stratigraphic data has demonstrated the western US Great Basin has experienced large hydrologic changes synchronous with abrupt climatic events during the deglacial period. Present chronologies of these changes have focused on large pluvial lakes (e.g., Bonneville, Lahontan, and Mono) within the context of lake level elevation, i.e., meters above sea level. However, assuming precipitation-evaporation is the dominant control on lake level changes, a more appropriate perspective may be through lake volume for the following reasons: 1) due to the intrinsic link between lake volume and basin geometry and 2) the extrinsic influence of basin geometry on evaporation potential. Volumes were calculated using a GIS approach from Mono Basin Digital Elevation Models at 1 m vertical resolution from the basin floor to the highest deglacial lake terrace.

The contrast in magnitude between the estimates of lake elevation and volume changes can be demonstrated from Mono Lake, CA. Mono Lake’s LGM lowstand to deglacial highstand fluctuation was an~190% rise in elevation(relative to its LGM lowstand). On the other hand, the volumetric increase was ~650%. Furthermore, this deglacial high was followed by a dramatic drop in lake level (~50% in elevation and ~250% in volume) at ~14.6 ka. Although using elevation to scale lake level changes is simple and straightforward to understand, critical climatic information may be lost by not considering volume. We are working to quantify the volume changes during significant climate events in order to better interpret the implied hydrological changes.

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