Seismic reflection imaging of suspected "windows" in the upper confining unit of the memphis (Tennessee) Aquifer
Abstract
Until recently, the Memphis (Tennessee) aquifer was believed to be well protected from downward vertical seepage of urban surface waters and groundwater in the surficial (shallow) aquifers by clay-rich layers of the upper Claiborne confining unit. However, recent studies of the Memphis aquifer and upper Claiborne confining unit show evidence of "windows" through the confining layer in the Memphis area. To investigate the size and structure of these confining layer breaches, S (shear) - wave seismic reflection profiles were acquired at two locations in the Memphis area. The reflection data were collected in SH mode (sensitive to horizontally polarized shear waves) and the seismic energy was generated by horizontal sledgehammer impacts on a steel I-beam oriented perpendicular to the spread. Data quality is moderate with variable amplitude, coherent reflection energy on all of the profiles. However, parts of the profiles are dominated by diffracted energy, indicating complex stratigraphy and/or structure. The most significant features imaged on the seismic data are near-surface paleochannels (∼ 140 to 350 m wide) cut into and through the confining layer, that may provide a hydrologic connection between the surficial (paleochannel fill) and Memphis aquifers.
Publication Title
Proceedings of the Symposium on the Application of Geophyics to Engineering and Environmental Problems, SAGEEP
Recommended Citation
Pell, A., Harris, J., & Waldron, B. (2005). Seismic reflection imaging of suspected "windows" in the upper confining unit of the memphis (Tennessee) Aquifer. Proceedings of the Symposium on the Application of Geophyics to Engineering and Environmental Problems, SAGEEP, 2, 797-805. https://doi.org/10.4133/1.2923534
