Marine Geoscience is the study of the physical structure and shape of the sea floor. Detailed knowledge of the sea floor is an essential first step in building up a comprehensive understanding of the marine environment.

Two major physical factors exist:

1. Topography (shape) of the sea floor – whether it is flat, if it is a steep slope, a cliff, interspersed with boulders, a large underwater canyon and so on.
   
2. Bottom composition (material) – whether the bottom is rock, sand, silt, mud, shell, coral or plants etc.
   Both are vital in establishing what physical habitats are present throughout the study area and how abundant each habitat type is.

The bathymetric and habitat maps generated by the geoscience team are the vital basal layer upon which we can overlay and analyse other data in our GIS system. Such information helps us to locate areas likely to contain caves in which coelacanths  take shelter during the day. It is also invaluable in assessing the location and extent of other habitat types. We use the maps extensively in planning ROV  and submersible surveys.

The topography provides an important link to the oceanography  of the region impacting on the flow of currents and localised upwelling cells. These are vital nutrient pumps, effectively creating hotspots of productivity likely to be of enormous importance to organisms and fisheries in the region. The detailed mapping of the shelf and slope provides an insight into the geological evolution of the continental margin and the formation of submarine canyons. What is particularly important is understanding the mechanism leading to the development of canyons and how they were modified by past changes in sea level and past climates. 

Marine geoscience research is of value to many users outside of the programme providing:

• data on past climates and future climate change predictions
• suitable trawling grounds and conservation sites
• marine charts for safer shipping
• possible mineral exploration target areas
• information on features such as large faults and submarine landslides which are potential tsunami threats

Geoscience uses a number of methods to gather this data:

• Multibeam swath bathymetry uses beams of high frequency sound waves to build up a detailed and very accurate picture of the bottom of the ocean.
• Sidescan sonar uses sound instead of light to take an “image” of the bottom, somewhat similar to an aerial photograph.
• Sediment samples to test acoustic (sound) survey interpretations and to study the composition, age and origin of the sediment. 
• Seismic surveys utilise loud sound sources to penetrate layers of sediment to determine their depth and structure.
• Visual “ground truthing” ensures that data are correctly interpreted and allows sonic signatures of particular habitat types to be discerned from each other.
• Coral cores, like tree rings record a yearly growth history and are used to construct a history of changes in sea temperature, flood events and weather cycles.

The goals of the marine geoscience component are to:

• Develop a team of highly skilled geoscientists
• Identification of target areas for detailed sea floor mapping on the continental shelf, slope and canyons. Marine protected areas are given priority attention given their relevance to conservation, management, education and promotion of tourism.
• Habitat mapping of the shelf and associated reef complexes, slope and canyons using multibeam systems and side scan sonar
• Integration of maps with SCUBA diving, submersible/ROV observations and grab samples to develop habitat maps.
• Generation of high resolution continental margin stratigraphy for the region using seismic methods, core sampling, micropalaeontology and geochronology
• Sampling of sediments and mapping of sedimentary structures to develop an understating of shelf sedimentary dynamics
• Detailed mapping of canyons to develop canyon formation models 
• Identification of palaeo-sea level history from canyon morphology
• Coral coring and analysis to determine palaeo-sea temperatures, flood events, pollution and palaeo-oceanographic dynamics

The geoscience component has been invaluable in our surveys at Sodwana bay. Notable achievements are:

• Bathymetric mapping of the Sodwana Bay canyons using multibeam swath bathymetry
• Obtained geological samples, submarine videos and single-beam soundings which have been used to verify (ground truth) and boost the multibeam data and to identify areas in which further geological sampling needs to be conducted.

The geoscience team currently comprises:
Co-ordinator: Dr. Ron Uken
PhD student: Andrew Green