Developing a Samplng System for Seabed Crust Deposits

The future exploitation of cobalt-rich manganese crust deposits will require a dependable system to characterize these deposits at potential seabed mining sites. The Bureau of Mines initiated research to develop a new sampling dredge by conducting a series of laboratory physical property and cutting tests on previously collected crust and substrate samples. Using the engineering parameters derived from these data, the Bureau, with the cooperation of the Minerals Management Service and U.S. Geological Survey, designed and constructed a new sample dredge system. This system was tested during a sampling cruise aboard the RV Farnella near Johnston Island in December 1986. The new system is capable of fragmenting and collecting in situ crust and substrate where the seabed is relatively flat. Where the seabed is rugged, the system is less effective. The research effort provided valuable input to future designs.