Deployed at our Fraser Delta site in the Strait of Georgia are various sonar systems. In addition to the upward looking echo-sounder (200 kHz ZAP), we have a downward looking scanning sonar built by Imagenex. Shown here is a series of single scan images, and when compiled into an animation, the time-lapsed set of hourly images shows the changes detected by the sonar. This scanning sonar sweeps out a radial scan of the ocean bottom to detect and monitor changes in the bedforms. Seen in these images is the corner of the instrument platform (lower left corner), and bottom roughness out towards the right. In the animations from May and June, we also see the daily occurrence of a high concentration of suspended sediment, when the entire image shows yellow and orange backscatter. These events, which occur during the peak freshet of the Fraser River, are associated with the downward settling of the river sediment after low tide.
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