To improve understanding of the shallow critical zone structure at Shale Hills, two REU students along with CZO post-doc scholar Nicole West and Professor of Geosciences Andrew Nyblade set up field experiments in the open soil pits on both the northern and southern slopes.  To perform the near surface refraction survey, geophones are placed in the soil pit walls, to a depth of 1 meter below the ground surface.  Vibrations are created by sledge hammers and strike plates and the ensuing seismic waves are recorded by the geophones.  Timing and intensity of the waves may be used to calculate material velocities, which will further knowledge of the subsurface structure.