High-resolution ultra-shallow subsurface imaging by integrating near-surface seismic reflection and ground-penetrating radar data in the depth domain

This study presents the integration of complementary near-surface geophysical methods for high-resolution ultra-shallow imaging of the subsurface. Shallow-seismic reflection (SSR) and ground-penetrating radar (GPR) data of approximately the same wavelength were collected along a coincident survey line. The top of the saturated zone was successfully imaged using both techniques, but no significant reflectors were imaged above the water table using SSR or below the water table using GPR. The SSR and GPR data sets were depth converted and merged into a single data set, resulting in a more complete image of the subsurface than either method can provide alone. Instead of having two sections representing depths of ∼ 0-5 m (GPR) and ∼ 4-30 m (SSR), the combined section includes the near-surface stratigraphy, water table, and bedrock, among other geologic features. It is important to note that this method of data merging is intended only for qualitative interpretation of layers of differing electrical and elastic properties. In the case shown here, the two geophysical methods image comparable features in depth, but they respond to different physical properties.