Here are some of the results from the initial testing [pdf] and some preliminary results from Tinkers Creek [pdf]. If you are interested in water isotope research, please contact Dr. Fasong Yuan at firstname.lastname@example.org or call at (216) 687-3508.
Lake sediments from the San Luis Valley, south-central Colorado, archive a detailed record of Late Glacial and Holocene climatic fluctuations in the southern Rocky Mountains. Together with radiometric dating analysis, measurements of grain size, magnetic susceptibility, total inorganic carbon (TIC), oxygen and carbon isotopic composition of the TIC fraction on sediment samples from San Luis Lake (at an average resolution of 60 years per sample) allow us to generate a continuous sediment record of climatic change in the region over the last 16.5 ka (1 ka=1000 cal yrs). This record documents the timing and duration of major climate episodes and trends, comparable to the existing paleoclimate records from the American Southwest. The Late Glacial record of San Luis Lake contains a big wet episode in the late part of the Mystery Interval (MI), a relatively dry climate during Bølling–Allerød (B/A) warm interval, and a relatively wet episode during the Younger Dryas (YD) interval, similar to the lake-level record found in the Estancia basin in central New Mexico. The early to middle Holocene record of d18O in the San Luis Lake parallels the calcite d18O record of Bison Lake in northern Colorado, documenting a history of significant change in precipitation seasonality across the northern boundary of the North American monsoon (NAM). The middle Holocene epoch is characterized by greater variations in magnetic susceptibility, d18O and d13C, suggesting the prevalence of wet, variable or transitional climate conditions. In contrast, the late Holocene climate is relatively dry, as indicated by more positive values of d18O in San Luis Lake. The results of this study reveal a complex history of climate evolution due to the interactions of two seasonally distinct precipitation regimes with mountainous landforms in the region.
A research project to better understand the sources and transport of bioavailable phosphorus into Lake Erie has recently been funded by US Environmental Protection Agency (EPA), Great Lakes National Program Office (GLNPO). This is a multi-institutional collaborative effort by researchers from Heidelberg University, John Carroll University, and Cleveland State University. In this project, our group will investigate the phosphorus dynamics in Lake Erie's major tributaries, the Maumee River, the Sandusky River, and the Cuyahoga River. More specifically, we will address the relationship between phosphorus saturation index (PSI) and bioavailability phosphorus (BAP) of riverine particulate. We believe the results of this work would eventually lead to formulation of a sustainable phosphorus management scheme for the Lake Erie Watershed.