The topogrpahy of the ocean's floor retains useful information on the geological processes that have shaped it because the ocean floors are generally less modified by erosion compared with the continents, which are eroded by runoff. On the other hand, in ocean areas where erosion is significant, the morphology of the seabed is also useful for revealing how erosion has occurred. This work therefore focuses on studying topographic and geophysical data of various kinds to study erosion, tectonics, sedimentation and volcanism in the oceans, through interpretation, numerical analysis and modelling. Data are collected in active sea-going field campaigns or studies are based on legacy data or 3D seismic datasets contributed by industry.
Continental and volcanic island slopes: The origin of submarine canyons, in particular morphological aspects such as long-profile concavities of passive margin canyons and knickpoints in canyons on tectonically mobile slopes. Scours produced by giant debris flows. Origins of the smooth, diffusive-like topography of the uppermost continental slope and parabolic interfluves. Erosion of slopes in the Canary Islands.
Mid-ocean ridges: Development of faults and volcanism at ridges, tectonic strain, low-angle faults, oceanic triple junctions, numerical analysis of lithologies and geomorphology in submersible observations, sediment deposits around ridges and their use in mapping and dating lava flows in areas of high pelagic input.
Coastal geology: Migration of sand waves from time-lapse multibeam sonar surveys, evolution of headland-connected tidal sandbanks in the Bristol Channel, sedimentary processes in the Celtic Sea.
Paleoceanography: How enhanced biological productivity in the equatorial Pacific Ocean surface waters has led to thick deposits of carbonate ooze around the equator, effects of productivity and reworking by currents. Seismic reflection data used to provide spatially continuous information on the deposits. Statistical modelling of deep-sea core data coupled with subsidence modelling to improve knowledge of Miocene circulation and how they were affected by early Cenozoic glaciations.
Volcanic ocean islands: How seamounts and islands develop radiating volcanic ridges and become modified by giant landsliding. Coastal processes, in particular how lava behaves on flowing into water as a result of cooling and changes in buoyancy.
Seabed mapping sonar: Developing methods based on Underwater Acoustics to interpreting sidescan sonar backscatter data, such as seabed penetration and subsurface imaging. Processing of multibeam echo-sounder data and, based on them, seabed characterization, classification and cable routing algorithms.
Contact: Neil Mitchell