Scott E. Noakes

Rapid coastal survey of anthropogenic radionuclides, metals, and organic compounds in surficial marine sediments.

A towed survey system, the GIMS/CS3, has been developed to enable the rapid measurement and mapping of a variety of physical and geochemical parameters in the surficial sediments of aquatic environments while the survey vessel is underway. With its capability for measuring radiometric, elemental and organic compound constituents of sediments, as well as bathymetry and water quality parameters, the GIMS/CS3 provides a cost-effective means of performing reconnaissance determinations of contaminant distributions and environmental monitoring tasks over broad geographic regions.

Comparison of Data Logger Operational Parameters Aboard Ship and Towed on the Seafloor

A number of new, submersible water quality data loggers(probes) have recently been introduced to the market place which have interesting applications to developing Environmental Impact Statements (EIS) and future surveys in the Exclusive Economic Zone (EEZ). The probe chosen for this study is typical of today. This probe has the capability for multi-parameter measurement of temperature (degrees Centigrade), dissolved oxygen (mg/1), conductivity (mmhos/cm), salinity (ppt), pH (units), and depth (meters). It can be preprogrammed for remote data logging, tethered by underwater cable to a surface readout, or operated aboard ship by a flow cell connected to a submersible pump. A new operational parameter was tested using the probe mounted inside a towed seafloor sled. A pump mounted inside the sled allowed a sediment-water slurry from the seafloor to be pumped aboard ship. A second probe was mounted on the survey ship with a flow cell connected to the submersible pump. With one probe on the surface and the other on the seafloor, a simultaneous comparison was made utilising the data collected on the same sediment water sample. Advantages gained from this study can be used to cross-calibrate in situ seafloor analyses with those made aboard ship. It also demonstrates the probes durability for seafloor measurements either in the static or towed mode of operation.

Marine sediment mapping systems for rapid coastal assessment

The Gamma Isotope Mapping System (GIMS) and the Continuous Sediment Sampling System (CS3) (Fig. 1) have been developed at the Center for Applied Isotope Studies, The University of Georgia in response to the growing need for a rapid, cost-effective tool that can assess the environmental impact of the urban and industrial growth along coastal regions. Capable of mapping radionuclides, metals, and organic compounds, the combined GIMS/CS3 has been widely utilized in tracking both point and non-point source marine sediment contaminants in estuarine and offshore environments. The system consists of a towed seafloor sled, which allows in-situ radionuclide measurement, and fine-grained sediment sample collection while the survey vessel is underway. Detailed two- and three-dimensional maps are compiled from the data collected by the GIMS/CS3 and utilized to identify trends associated with point and non-point pollution sources.