Remote Sensing of Submarine Springs: Floridan Plateau and Jamaica, West Indies.

Kohout, F; Kolipinski, M; Higer, A

A change in the turbidity plume formed by a submarine spring located 2-1/2 miles (4 km) offshore from Crescent Beach on the northeast coast of Florida suggests that flow from the spring may be decreasing in intensity with time. This decrease may correlate with increased pumpage in the artesian Floridan aquifer which underlies the mainland. In a cooperative project with the United Nations Development Program and the Jamaica Geological Survey Department, the National Aeronautics and Space Administration took more than 17,000 frames of color and infrared color photography of Jamaica and its coastal waters in April 1971. Submarine springs on the north-central coast of Jamaica discharge primarily clear water from karstic limestone and were not discernible from the aerial photos. In contrast, submarine springs on the south coast discharge from sand and gravel aquifers and turbidity plumes are clearly visible in photographs. At Discovery Bay, on the north-central coast, three factors - small ground-water discharge at the end of the dry season, small temperature differential between the ground water and the bay water at this particular season, and rapid mixing of the spring discharge (observed by SCUBA diving) - coincided so that thermal anomalies on the IR imagery were inconclusive. A significant anomaly was discovered in infrared imagery of the north-east coast of the island after the investigation was completed. The anomaly is presumed to be evidence of submarine ground-water discharge. Finds of this type combined with ground truth investigations and repetitive observations from satellite or aircraft platforms can provide a relatively inexpensive foundation for continuous surveillance and monitoring of earth and water resources.