Constraining the Stratigraphy and Depth to Bedrock at the Forest River Salt Marsh in Salem, MA

Abstract

The stratigraphy and depth to bedrock at the Forest River salt marsh in Salem, MA was constrained using seismic refraction methods. A ~2 m layer of peat was found on top of a layer of glaciomarine clay, with a transition layer in between. The depth to bedrock was constrained to greater than 19.5 m. Two surveys were completed and each had different p-wave velocities for both of the materials. The tide and weather conditions were then researched. It was concluded that the change in p-wave velocity from one survey to the next was due to a change in density caused by an increase of moisture in the area.