WAMSI 2 - Dredging Node 3.2.1 - Plume Characteristics (Field) - Field Trip 2

Plume Characterization:
The key objectives of Project 3.2:
(1) Characterize the physical/optical properties of sediment suspensions;
(2) Map the dredge-generated plume;
(3) Provide data to optimize and validate plume modelling;
(5) Assess the spatial and temporal variability (~10 years) of background suspended sediment loads using archived remote sensing data;
(6) To estimate the benthic light field with respect to TSS;

3D plume mapping was conducted over a 10 day period at Chevron’s Wheatstone dredging operation near Onslow Western Australia. Dredge plums created by a cutter suction dredge were sampled from CSIRO vessel RV Linnaeus on voyage number LI2014_v11. Underway measurements were made using a ship mounted ADCP to measure vertical velocity profiles and backscatter intensity and DALEC that measured the spectral qualities of incoming and reflected sea surface light. Profile data were collected using LISST (particle size distributions) , CTD (backscatter, temperature and salinity), Hydroscat, Hydrorad (used measure light profiles, extinction coefficients , and scattering properties). Surface and bottom water samples were be collected at selected sites and analyzed for particle size distributions

A mooring was deployed for 8 days in 8 metres of water. The mooring consisted of two Acoustic Doppler Velocimeters (ADVs) and an ADCP