Abstract
Logging was an essential part of western Wisconsin's economy from the 1850s to the 1920s. The logging industry used Half Moon Lake (HML) in Eau Claire as a holding pond awaiting processing at sawmills along the lakeshore. During the logging era, industrial wastes such as bark, sawdust, and slabs, were dumped on top of a former natural lake bottom (fluvial gravels). Although the logging industry use of HML ceased decades ago, the effects of the logging industry on HML's water quality can still be observed today. The industrial waste has been hypothesized to be several meters thick throughout the lake. To investigate the geometry of the industrial waste, a low frequency (50 and 100 MHz) pulseEKKO ground penetrating radar (GPR) survey was undertaken. Radar stratigraphic analysis of the GPR lines allowed for areas of interest to be located and Vibra-Cored to extract sediment samples. To georeference all collected data, a Trimble proXR differential GPS was used. Volume calculations were determined from GPR profiles to create a bathymetric and thickness map of the organic waste in HML.