Field setup of a Multichannel Analysis of Surface Waves (MASW) survey conducted along the Mississippi River in Vicksburg, Miss. The survey had a fixed spread of 72 geophones spaced 1 meter apart. The geophones were 4.5Hz and a sledgehammer with a steel plate was used as a source of energy. The U.S. Army Corps of Engineers St. Louis District is partnering with the U.S. Army Engineer Research and Development Center during a six-month detail program, known as ERDC University, to develop a broader understanding of shallow seismic exploration and its application as a tool for delineation and risk management using MASW. (U.S. Army Corps of Engineers photo)