Using geological history of the Laurentian Great Lakes to better understand their future

Abstract

With growing use of numerical models to forecast lake conditions under future climates and other stressors, paleo-events in the history of the Great Lakes have greater potential for relevance. Past events and history may extend records of observations, provide estimates of the sensitivity of the lake system to stressing conditions, and contribute scenarios for model validation. Here we describe four examples that hold promise for improving understanding of the present and future Great Lakes: 1) using an event of lake closure to derive climate-hydrology sensitivity, 2) extending the record of lake-level history by examining beach ridge sequences, 3) investigating sedimentary black bands to indicate past anoxia at the lakebed in deep basins, and 4) deriving evidence of lake process teleconnections with atmospheric circulation.