USSEABED: DEFINING THE SURFICIAL GEOLOGY OF THE CONTINENTAL SHELF THROUGH DATA INTEGRATION AND FUZZY SET THEORY

Decades of research in the oceans off the United States has provided the geological and biological communities with a wealth of information on sediment texture (hard rock, gravel, sand, mud), composition (i.e., light and heavy minerals, glauconite, shells, carbonate, organic carbon), structure (i.e., bioturbation, lamination, compaction) and associated biota (i.e., kelp, seagrass, gastropods). Gathered by multiple research entities (USGS, NOAA, state and local governments, universities, and private corporations) these data in their original forms are diverse and cumbersome to manage and use.

With the realization that this abundance of data exists and could be mined for multiple uses, usSEABED combines and unifies quantitative and verbal core, dredge, and other seafloor data such as photographs and videos, to allow researchers and managers an integrated understanding of continental shelf sediments. As much of the information about the seafloor is in rich descriptions, and many geologic and biologic parameters are not in absolutes but in shades of gray ("homogeneous", "poorly" to "somewhat" to "well laminated"), fuzzy set theory is applied to parse verbal descriptions into relative quantitative measurements. These coverages, combined with quantitative measurements and further modeled, expands knowledge of the sea floor.

Developed in conjunction with its Australian counterpart, auSEABED, usSEABED basic data is held as a tree-d, comma-delimited format; the outputs are suitable for input into most COTS database software or GIS.

In areas of rich and dense data coverage, such as the Southern California Borderland and offshore Central California, usSEABED can generate maps of surficial sediments that are more than textural maps, but rather include, where available, areas of hard ground, bioturbation, bedforms, sediment color, or concentrations of wood or shells, as examples. Current uses of usSEABED include an investigation of benthic fish-sediment correlations, in sonar propagation modeling, and as ground-truthing for remotely sensed images, with many more applications potentially available.