Figure 7. Sidescan-sonar image superimposed on the surficial geology map showing a submerged sea stack off Grayland (upper panel), and the seismic-reflection profile collected along the same line showing this intrusive structure (lower panel). Photograph from the station in the high-backscatter areas shows this area to be gravel.  Click on the figure to view a larger image. Figure location shown in Fig. 4.