Coastal & Marine Geology Program > Center for Coastal and Watershed Studies > Open File Report 01-303

A Summary of Findings of the West-Central Florida Coastal Studies Project

Introduction: Purpose & Scope Strategy, Data, & Products Study Area Characteristics Early Geologic History Coastal/Inner Shelf System Study Objectives: Primary Objectives Study Findings: Processes Geologic Template Infilled Shelf Valleys Shelf Sedimentary Cover Hardbottom Development Barrier Island Studies Ramifications References Appendices: Appendix 1 Appendix 2 Appendix 3

Project Purpose, Scope, and Approach Figure 1. Various coastal sectors of Florida shown in upper map. Lower map shows location of the study area within the northern part of the west-central Florida barrier-island chain. [larger version] This report summarizes the major findings of a United States Geological Survey (USGS)-funded project entitled the "West-Central Florida Coastal Studies Project" and managed by the USGS Center for Coastal Geology and Regional Marine Studies in St. Petersburg, FL. USGS scientists from Woods Hole and Menlo Park were involved as well. This project was a co-operative five-year venture with scientists from Eckerd College and the University of South Florida College of Marine Science (Center for Coastal Ocean Mapping) and the Department of Geology (Center for Coastal Geology) designed to conduct a geologic framework study of a barrier-island coastline and its adjacent inner continental shelf off west-central Florida (Figure 1). Early results are presented in Gelfenbaum (1995, 1997a,b), Siegel et al. (1996), Weisberg et al. (1996, 1997), Gelfenbaum et al. (1998), Hine et al. (1998), and Brooks et al. (1998, 1999). This project is a regional study examining the geologic framework of a large sector of coastal zone and inner shelf. A regional study allows us to examine large coastal sectors as a single entity and as a sum of interacting parts, i.e., rather than study single elements such as one barrier island and one inlet. This approach allows us to examine a connected series of barrier islands and inlets and provides for a more synergistic understanding of coastal geology. It links the barrier islands to the adjacent inner shelf rather than viewing the two as separate, disparate components. It assists us to determine underlying causes of beach erosion, potential sources of sand, past effects of storms, and other factors significant to human needs. A geologic framework approach allows us to step back in time to see how this coastal system has evolved to its present configuration. Finally, these data might eventually provide a basis from which predictions on coastal behavior can be made. Primary characteristics of the geologic framework include: effectiveness of antecedent topographic control (karst features, shelf valleys), identification of major sediment sources and sinks (sand bodies, headlands), nature of the shallow, subsurface stratigraphy (lateral/vertical variations in lithology), thickness and lithologic, textural character of the active sediment cover, nature of biologic controls present or past (e.g., biologic sediment production from hardbottoms), and identification of major geologic events of the past that explain present-day morphology and distribution of geologic products (e.g., sea-level changes, climate changes). These are primary themes derived from the data products presented in Appendix 1 and are presented collectively in the abstracts, theses, dissertations, and publications referenced in Appendices 2 and 3. Overall, the primary goal of this regional study was to understand the natural variability of coastal morphology, seafloor bathymetry, surface sediment distribution, and subsurface stratigraphy of an extensive coastal system. An additional component was to understand shelf water circulation and how that interacts with this coastal/inner shelf system. This regional study was designed to view a naturally-bounded coastal sector as a field laboratory, which captures most of the spatial variability of a specific coastal type—in this case a low energy, sediment-starved, barrier-island system significantly influenced by underlying antecedent topography. Locally, coastal engineers, planners, government officials, and interested citizens can use these data products in managing coastal resources for the west-central Florida coast. More broadly, the national and international coastal geologic community can use the techniques presented, the database produced, and the conclusions drawn as a contrast to and comparison with other coastlines worldwide. Additionally, we offer this study as one example on how regional coastal studies should be done. 1College of Marine Science, University of South Florida, St. Petersburg, FL 33701 2Department of Marine Science, Eckerd College, St. Petersburg, FL 33711 3Department of Geology, University of South Florida, Tampa, FL 33620 4U.S. Geological Survey, 345 Middlefield Rd., Menlo Park, CA 94025 5U.S. Geological Survey, Quissett Campus, Woods Hole, MA 02543 continue to Field Strategy, Data Base, and Products

Printable Version Related Research Project: West-Central Florida Coastal Studies Project USGS Coastal & Marine Geology Program Related Publications: West-Central Florida Coastal Transect Series - USGS Open File Reports 99-505 - 99-513 USGS Coastal & Marine Geology Program Factsheet: Limited Sand Resources for Eroding Beaches USGS Coastal & Marine Geology Program Related Link: Virtual Field Trip of west-central Florida's barrier islands USGS Coastal & Marine Geology Program

Coastal & Marine Geology Program > Center for Coastal and Watershed Studies > Open File Report 01-303