A seventeen year, near-annual, bathymetric time-series of a marine structure (SS Richard Montgomery)

摘要

The wreck of the SS Richard Montgomery, sunk off the Isle of Sheppey, UK, in 1944, has beenrnsurveyed with high resolution swath bathymetry, a total fourteen times over a seventeen year period.The structurernsits on a sandbank at a maximum depth of 20m and is sub-aerially exposed at all tidal states. Ambient sedimentrntransport is restricted to the flood tide and during storm conditions, resulting in a triple-lobed scour pit elongatedrnin the flood tide direction. Despite maximum bed-level change, within the zone hydrodynamically influencedrnby the structure, occurring over a range of ±2.5 m/yr, total bed-level change over the survey period was onlyrn−0.6 m, with yearly averages of <±0.1 m. This long-term (inter-annual) balance between bed-level loss andrngain is suggestive of a self-contained system.