Showing papers by "Lionel Carter published in 1992"

Acoustical characterisation of seafloor sediments and its relationship to active sedimentary processes in Cook Strait, New Zealand

Abstract: 3.5 kHz seismic profiles are used to characterise the seabed in Cook Strait. The various acoustical responses have been classified into nine groups or echo‐types which, together with sediment samples, photographs, and side‐scan sonography, provide an insight into modern erosional and depositional processes operating in the strait. Much of northern Cook Strait is underlain by semi‐consolidated, late Pleistocene sediments that are eroded by strong, tide‐dominated currents even at depths >200 m. Locally, erosion of these deposits is impeded by a lag gravel pavement that occupies much of the 150–350 m deep central strait. The same strong currents effectively transport bedload along the Wellington continental shelf, which is a rocky platform with a patchy veneer of mobile sand and gravel. Outside the main tidal stream, within semiprotected embayments, deposition is manifest by prominent sediment bodies of mud and sand prograding across the inner‐middle shelf. Seaward of the shelf, in southern Cook Str...