http://dep.state.fl.us/geology/geologictopics/sinkhole.htm Florida Department of Environmental Protection Florida DEP sinkhole page Florida Geological Survey Datos geologicos "DRAM, FGS, Sinkholes in Florida" Florida Geological Survey Florida DEP sinkhole page Florida Florida’s Department of Environmental Protection Florida Geological Survey http://dep.state.fl.us/geology/geologictopics/sinkhole.htm "DRAM, FGS, Sinkholes in Florida"