Springs of the district

Crescent Beach Submarine Spring

Crescent Beach Submarine Spring in St. Johns County

Crescent Beach Submarine Spring is at least a second-magnitude spring. The spring is situated 59 feet below the surface of the Atlantic Ocean, and the spring boil can be seen at the sea surface on a calm day. The sea floor around the spring is level. However, numerous subsurface structures appear around the area of the spring (Kindinger 2000).

The interpreted seismic reflection profile reveals a well-defined vent feature that appears to have been developed and maintained from submarine discharge of artesian water (Swarzemski et al. 2001).

The profile also reveals multiple large collapse features directly adjacent to the Crescent Beach spring vent, as indicated by the presence of a series of fractures. The density difference between the freshwater discharges from the spring and seawater can be seen in the seismic reflection profile of the water column. The spring appears to be a recent, incised spring vent rather than a collapse structure. The northern side of the vent is higher than the southern side. For a more complete discussion of the seismic profiling and the visual scuba observations, the reader is directed to Brooks (1961) and Kindinger (2000).