South Wales-based Titan Environmental Surveys has recently completed a survey contract for this project commissioned by Mouchel Consulting on behalf of CSX World Terminals. The coastal survey section of Titan was required to undertake geophysical, oceanographic and water quality surveys, collecting data for input to a numerical modelling system. This will be used in determining the optimal design for the proposed container terminal development as well as for assessing the environmental impact of the port in terms of both construction and operation.

The main aims of the survey were to provide comprehensive information to facilitate terminal construction in an environment consisting of calcareous sand over heavily voided cretaceous limestone. The survey objectives were to determine topography, bathymetry, geomorphology & lithology as well as identifying seabed feature and characterising the marine environment.

Geophysical surveys were conducted over three weeks from a 45ft vessel of opportunity while bathymetric data were collected from a 25ft open boat. Data collection proved particularly challenging due to prevailing oceanographic conditions, with swells frequently in the range of 2m and an irregular coral seabed in the geophysical survey area. Good penetration was, however, achieved through the calcareous sands and it was possible to map the interface of calcareous sands to the coral limestone to depths of 30m sub-seabed.

The resulting data confirmed that the limestone substrate was heavily eroded and had been subjected to a history of great tectonic uplift and resulting sea level change. The area is characterised by a multitude of marine terraces and sea caves.

The proposed site for the container terminal was observed to be a limestone/coral shelf, greatly eroded with partially collapsed caves.

Titan subcontracted the Belgium-based firm Demco to carry out further geophysical work using the Aquares resistivity system to ascertain the positions of fissures in the soft corralitic limestone of the area. The system used both surface and bottom towed electrode arrays to identify a number of fissures in the coral as areas of significance for future borehole investigations.

Titan has also recently completed geophysical work in the Red Sea using their own 9m purpose-built survey catamaran Titan Surveyor, and are currently surveying sites under consideration for offshore wind farm development.

MJ Information No: 17105