MEASUREMENTS OF HIGH-CONCENTRATION SUSPENDED SEDIMENTS USING THE OPTICAL BACKSCATTERANCE SENSOR

An optical backscatterance sensor (OBS(TM)) was used to measure extremely high concentration suspended sediments on the Amazon continental shelf as part of the AmasSeds project (A Multidisciplinary Amazon Shelf Sediment Study). Using a pumping system for obtaining water samples to calibrate the sensor in situ, the OBS output was observed to increase approximately linearly for concentrations < 10 g/l, but decrease approximately exponentially for concentrations > 36 g/l. The OBS response was nearly continuous from 0 to 320 g/l making it possible to obtain continuous suspended sediment concentration profiles through fluid muds.