Detection & Mapping of Minerals, Hydrocarbons, Pipelines, UXO, and other Polarizable Materials in Marine and Fresh Water Environments
Kari Walker* (1)
Mike Williamson (1)
Jeff Frank (1)
Jeff Wynn (2)
Marine Induced Polarization (marine IP) is a technology developed in partnership with and patented by the US Geological Survey (USGS) for the detection and mapping of minerals, hydrocarbons, pipelines, and other polarizable materials. Marine IP is distantly related to seabed resistivity, but uses phase-shifts induced in reactive materials instead of volume resistivity. Chargeable materials include sulfides, hydrocarbons, metallic debris including wrecks, pipes and cables, and titanium oxides including ilmenite, a mineral that accumulates with other heavy placer minerals such as gold, diamonds, and platinum. Marine IP can detect very low levels of hydrocarbons in the water column or sequestered in seabed sediments by measuring capacitance.
The physical application involves deploying a cable or streamer array towed behind a vessel, on the sediment or suspended in the water column, introducing a controlled electrical current into water, and measuring the distinct return signals to map polarizable contaminants. Marine IP can detect down to 20 meters into the sediment, where both depth and resolution of detection are a function of the electrode spacing on the cable or streamer array. Marine IP array streamers have been used to locate very large ilmenite deposits off South Africa, sulfides off Papua New Guinea and naphthalene and creosote tars at the Wyckoff site in Eagle Harbor and the Quendall Terminals site in Lake Washington, Washington State. Induced Polarization Associates, LLC has an exclusive license for the USGS patents to further develop and commercialize marine IP technology.
(1) Induced Polarization Associates
(2) United States Geological Survey