Side Scan Images

Rotary side scan images at a grain-size boundary at a 12-m deep site south of Martha’s Vineyard. Gray images are fan-beam sonar backscatter amplitudes, and colored insets are bathymetry, with 0.02-m contours. Both images were made at the same location under different wave conditions, as indicated in the bottom panel, where ubr is wave-orbital velocity  (m/s) and wave dir. (degrees True) is wave propagation direction (relative to north).