Investigation Methods and Procedures - Geotechnical Engineering Investigation - page 26

FIGURE 2.8 ( Color Figure 2.8 follows page 396.)
Aerial photos of a bridge abutment illustrating the advantage of infrared over true color. On the left is
vegetation growing over shallow, poor-draining marine shales. On the right are relatively free-draining
granular glacial soils with sparce vegetation. (a) True color photo; (b) color infrared photo (CIR). (Courtesy
of Woodward-Clyde Consultants.)

Seaborne Imagery

Side-scan sonar provides images of the seafloor or other water bodies, which often
have features indicative of significant geologic conditions. The images given as
Figure 2.9 were obtained for a landslide study where the failure surface passed

●