The Offshore Sand Resources Study
In 1992, Maryland Geological Survey, Delaware Geological Survey and the U.S. Minerals Management Service formed a 5-year cooperative study to explore and inventory potential offshore sand resources in federal waters off the Delmarva coast. In Maryland, our objectives were to: Identify potential sand deposits Determine which deposits are most likely to contain sand suitable for beach nourishment Estimate the amount of sand available in each deposit Beach nourishment projects demand that sand resources meet certain physical, economic, and environmental criteria. Sand used for replenishment must be of an optimum grain size. This optimum grain size is determined by complex factors such as the topography of the beach and surrounding offshore regions, and the amount of wave and wind energy available along the shoreline. These kinetic factors are specific for every stretch of shoreline. The grain size of native beach sands is in part a measure of these factors. Therefore, the optimum grain size for nourishment sands should approximate the grain size that naturally occurs on the beach. The volume of sand required for replenishment is also dependent on these factors. Fine sand is more rapidly redistributed by wind and wave energy than coarse sand. If sand placed on the beach is finer than the native sand, a larger replenishment volume will be required. Proximity of sand resources to the beach nourishment project is an important economic factor. Environmental factors include sand mining and transportation impacts, and the aesthetic appearance of the borrowed sand. Based on these and other considerations, The U.S. Army Corps studied these factors, and many others, and concluded that offshore sand deposits are the most desirable for beach nourishment projects in Maryland. The goal of the Offshore Sand Resources Study is to identify the quality and quantity of potential offshore sand deposits.