Ground-Penetrating Radar And Swept-Frequency Seismic Imaging Of Shallow Water Sediments In The Hudson River

Ground-penetrating radar and swept-frequency seismic sub-bottom data were collected on the<br>Hudson River between Kingston and Saugerties, New York, in April, 1999, as part of a pilot project to<br>create a comprehensive benthic map of the Hudson River. The radar and seismic data were collected<br>simultaneously to evaluate the usefulness of each method for shallow-water stratigraphic mapping. The<br>data were used in preparation of a benthic map and for creation of a facies distribution map.<br>The results show that in shallow water (less than 20-feet deep) in the Hudson River, the radar<br>method obtains better penetration and resolution than the seismic method. Virtually all radar data<br>collected in shallow water shows detailed sub-bottom structure, whereas 65 percent of the seismic data<br>does not show any sub-bottom penetration, due to the presence of methane gas in the sub-surface and<br>(or) a hard water bottom.<br>The majority of the interpreted facies show sub-bottom deposition that formed in a relatively low<br>energy environment. Significant changes do occur over relatively short distances however. This allows<br>a GIS-based interpretation of the mapping of the spatial distribution of the facies and the recognition and<br>differentiation of sedimentary regimes in the river.