ACOUSTICAL AND OPTICAL BACKSCATTER MEASUREMENTS OF SEDIMENT TRANSPORTIN THE 1988-1989 STRESS EXPERIMENT

During the 1988-1989 Sediment Transport Events on Shelves and Slopes ( STRESS) experiment, a 1-MHz acoustic backscatter system (ABSS), deploy ed in 90 m of water off the California coast measured vertical profile s of suspended sediment concentration from 1.5 to (nominally) 26 meter s above bottom (m.a.b.). An 8-week-long lime series was obtained, show ing major sediment transport events (storms) in late December and earl y January. Comparison of the acoustics measurements from 1.5 m.a.b. ar e made with optical backscatter system (OBS) concentration estimates l ower in the boundary layer (0.25 m.a.b.). Correlations between ABSS an d OBS concentration measurements and the boundary layer forcing functi ons (waves, currents, and their non-linear interaction) provided a var iety of insights into the nature of the sediment transport of the STRE SS site. Transport rates and integrated transport are seen to be domin ated by the largest storm events. Copyright (C) 1996 Elsevier Science Ltd