The multi-channel analysis of surface waves (MASWs) method was used to obtain the shear wave velocity variations through near surface (depth 2. 300 m/s) is very large. The MASW velocity results compared with those of other geophysical approaches. such as seismic reflection/refraction methods and borehole data. https://www.roneverhart.com/Echo-Fix-EF-P2-Spring-Reverb-Pedal-p32083/