Near-surface imaging using coincident seismic and GPR data

In many near-surface applications, detailed subsurface-characterization is important. Characterization often is obtained using ground-penetrating rada r (GPR) or shallow seismic-reflection (SSR) imaging methods, depending upon depth of interest and surficial geology. Each method responds to different physical properties; thus, each may produce different images of the same n ear-surface volume. By incorporating the two methods, we generated a cross- section of the subsurface at an alluvial test site and identified the depth s of three interfaces accurately to +/-5 cm. We present here experimental r esults and examples of SSR and GPR images obtained along the same traverse, showing coincident and noncoincident reflections from multiple interfaces within 3 m of the surface.