Real-Time Characterization of Mine Scour Burial at the Martha's Vineyard Coastal Observatory

Mine burial by scour was measured in real-time using two cylindrical instrumented mines connected to a shore-based facility at the Martha's Vineyard Coastal Observatory (MVCO). Data on mine movement (heading, pitch, and roll), scour pit geometry, percent burial, and environmental processes responsible for scour burial, including significant wave height, period, and tidal height were analyzed daily and presented on the NRL web site (http://www7430.nrlssc.navy.mil/bblp/mine/realtimedata). Scour pits developed in response to storm-generated wave heights of up to 2.5-meters that occurred within the first 5 days of the experiments. The two instrumented mines pitched (3 to 9 degrees), rolled (35 to 55 degrees), and reoriented to align axially (up to 40 degrees) with incoming swell as they rolled into scour pits. The mines were buried level with the seafloor after a second storm. Subsequent storms with wave heights up to 3.5-meters were unable to further bury the mines. A comparison of the observed mine burial and real-time predictions (http://www.vims.edu/physical/projects/CHSD/projects/MBP) using a modified Whitehouse-Soulsby, wave-induced scour model were nearly identical, suggesting mine burial by scour is predictable from bathymetry, sediment type, and measured or predicted surface wave conditions. (13 figures, 7 refs.)
Presented at the International Symposium on Technology and the Mine Problem (6th). Prepared in collaboration with OMNI Technologies, Inc., New Orleans, LA, Virginia Institute of Marine Science, Gloucester Point, VA, and the Woods Hole Oceanographic Institution, Woods Hole, MA. The original document contains color images.