By understanding the critical zone, we gain valuable insight into physical, chemical, biological, and geological processes upon which all life is dependent. Despite this the critical zone is still poorly characterized and understood. In an effort to better understand the formation and weathering processes of the critical zone in the Susquehanna Shale Hills Critical Zone Observatory, two 2D velocity models were generated as a part of a large-scale seismic survey. One profile was parallel to bedding, and one was perpendicular. Models generated from the survey indicated that depth from surface to bedrock is fairly constant at 15 m. Velocities in both profiles are similar, indicating that there is little seismic anisotropy caused by bedding orientation. Models also indicate thicker soil profiles on north facing slopes, consistent the hypothesis that with weathering and formation of the critical zone at the Susquehanna Shale Hills CZO is dominated by aspect driven differences and therefore freeze thaw cycles.
Cole, Chad (2019): Using Seismic Refraction to Examine the Formation and Weathering Processes of the Critical Zone . Bachelor of Science, Geosciences, The Pennsylvania State University.