Underground GPR measurements for spatial investigations in a salt dome
Ground penetrating radar (GPR) is an efficient non destructive tool for the exploration of underground salt deposits. The complex geological structures (bent, folded, sometimes faulted layering of salt, potassium, clay, and anhydrite) in low-conductive salt can be mapped if distance and direction of reflecting objects are known. In boreholes the information is given by direction sensitive borehole radar. In shafts rotation symmetry helps to detect the direction. In drifts direction finding antennae provide the reflection angle. Various antenna types help to enhance the resolution or the penetration depth. Measurements with different polarizations offer additional information about the reflecting structures. Within the last two decades unique results from a salt dome in Northern Germany with various GPR systems were achieved. With this information and some geological knowledge a three dimensional model of the structures has been created.
GPR measurements in drifts at the northern part of the Morsleben salt structure
The Allertal salt structure, used as repository for nuclear waste, was explored from the surface by seismic measurements and boreholes. Due to the accuracy of these investigations the position of the steep flank in the west of the salt structure is known. Underground, GPR (Ground penetrating radar) is an efficient and precise nondestructive tool for the exploration of salt deposits. The complex geological structures (bent, folded, sometimes faulted layering of salt, potassium, clay, and anhydrite) in low-conductive salt can be mapped if distance and direction of reflecting objects are known. Drifts parallel to the flank in the northern part of the salt structure allow getting this structural information by GPR. With these results and some geological knowledge a three dimensional model of the flank and other salt structures can be created.
Thermal properties of the Florida Current as related to Ocean Thermal Energy Conversion (OTEC)
The thermal properties of the Florida Current are presented and analyzed for the available ocean thermal energy. For a cold water intake depth equal to or greater than 600 m, potential sites for Ocean Thermal Energy Conversion (OTEC) power plants appear to exist in the Straits of Florida and, to a lesser extent, off the coasts of Georgia and South Carolina. The maximum thermal differences occur on the continental shelf because of the geostrophic motion of the Gulf Stream. An estimate of the total available ocean thermal energy from the Florida Current, delivered in the form of electricity, is 3.5 × 1012 kWh yr−1. For a cold water suction depth of 600 m or more, seasonal variability in the ocean thermal resource is approx. ±35 per cent of average annual output.