I. Geology of Florida Coast
    A. Introduction
        1. Coasts have variable morphologies in response to different settings and processes
        2. Florida's coast is the longest and most diverse of the lower 48 states
        3. Variable widths of the continental shelves (narrow on the Atlantic and wide on the Gulf); coastal orientations; sediment   types and availability
        4. Periodic tropical cyclones (hurricanes)
        5. Types of Coasts
            a)  East Coast barrier island system
            b) Marsh in the Big Bend area
            c) Apalachicola Delta area
            d) Central Gulf barrier islands
            e) Mangrove coast of SW Florida
            f) Florida Keys
        6. Major human impacts on coast are due to population density and development
        7. Coast is all Quaternary with the active coast dominated by Holocene sediments and strata (exception would be the Anastasia in the Atlantic Coastal Ridge)
        8. Factors used for coastal classification are:
            a) Energy level
            b) Littoral drift rate
            c) Equilibrium
            d) Down-shore variability
            e) Tectonic stability
            f) Sea level stability
            g) Materials present
            h) Non-marine agents (rivers)

II. General Setting
    A. Geography and climate are important variables
    B. Continental and trade winds dominate climate with periodic tropical storms
    C. Estimate of energy level can be made; log R (m3/yr) = 1.577 Hb (wave height in cm) + 2.62
    D. Overall Coastal Processes
        1. Weather is one fundamental factor affecting Florida's coast
            a) Wave height and longshore drift differ in summer and winter (N to S on east coast and E-W in the Panhandle); winter pattern is for northeasters (beach erosion problems)
            b) Net transport is N-S on the peninsula (500,000 m3/yr) and E-W on Gulf Coast (100,000 m3/yr); 200,000 m3/yr in the Panhandle
        2. Waves
            a) High energy south of Cape Canaveral as the shelf narrows and steepens
            b) Lower energy on the NE coast with the broad shelf and shallow slope
            c) Gulf Coast is low energy due to wide, shallow shelf and limited fetch
            d) Panhandle Shelf is narrow and steep except for the Apalachicola Delta
            e) Waves dominate process along the southern east coast including the Keys and the Panhandle
    3. Tropical Storms
            a) Florida is in the path of major tropical storms
            b) Major shoreline changes may take place in a short time period
            c) Hurricane Andrew, a major storm with modest to little impact on the coast due to relative small size (not intensity) and rapid movement
    d) Hurricanes Georges (1998), Earl (1998), and Opal (1996) was slow moving and did a lot of storm damage in the Panhandle
            e) Greatest risk remains on the SE coast of Fla. and the Panhandle based on "normal" storm tracks
        4. Tides
            a) Tidal range is microtodal (<2m) throughout Fla. except NE where the Spring ranges may be greater
            b) Tides interact with waves to shape the coast
            c) Mangrove coast of SW Fla. and the swampy Big Bend area are dominated by tidal (not wave) effects
            d) Mixed energy on the NE coast and west-central barrier islands
            e) Tidal prism (daily tidal budget) is important and varies with geometry (mostly area) of coastal features
        5. Geology is the second most important factor affecting coastline; perching of the east and west coasts on limestones to    prevent and minimize erosion

III. Late Holocene Sea Level
    A. Rate of sea level rise
        1. Early Holocene about 1 cm/yr; on a 1/1000 gradient results in a 1 km intrusion/yr in the Sarasota area
        2. From 8,000 to 3,000 YBP, the rate was about 25 cm/100 yr (0.25cm/yr)
        3. Since the year 3000, rate is only 4 cm/100 yr (0.04 cm/yr)
    B. Low relief and lack of sediment sources has resulted in reworking of older Quaternary materials except for the Apalachicola Delta
    C.  Rapid sea level rises prevent the development of stable coastal morphologies; rate must be below 3 mm/yr to develop a stable coast
 

IV. East Coast Barrier Islands
    A. Geomorphology
        1. 550 miles of barrier islands and inlets
        2. all, but Matanzas, influenced by engineering activities
        3. Cape Canaveral and south have different orientations and sedimentation patterns and are wave dominated
        4. Predominantly quartz with major carbonate at Anastasia Island and in the Anastasia Formation (Atlantic Coastal Ridge)
        5. Anastasia Fm is the remnant of a Pleistocene barrier island; the only "rocky" coast of Fla.
        6. NE Fla. has typical short barrier islands with well-developed sand dunes and extensive marsh and tidal flat development; typical of mixed-energy environment
        7. South of Matanzas the coast is wave dominated and characterized by barrier islands with long continuous dunes rather than the high dune ridges (8-12 m) with a prominent long shore bar and trough system; beach widths are variable
        8. This area has little marsh development and is characterized by lagoons with rather fresh water away from inlets (Indian River and Halifax River for examples)
    B. Sedimentary Processes
        1. The rather wide shelf and Bahama Islands provide some protection against waves along the east coast
        2. North of Cape Canaveral longshore transport is south with decreasing amounts of sediment
        3. Reversals of coastal patterns form in littoral cells that can be large; convergence can result in beach ridge growth and divergence can result in erosion

V. Southwest Florida Mangrove Coast
    A. General
        1. Tidal dominated
        2. Divided into two areas
            a) Northern portion-Ten Thousand Islands
            b) Southern portion -adjacent to the Everglades; lacks distinct mangrove islands
        3. Geology and Geomorphology
            a) Divided into northerly quartz sand area (Cape Romano) and carbonate area (Cape Sable) and southerly mangrove swamp coast
            b) Underlain by Pliocene Tamiami Formation and Pleistocene Miami Oolite covered by eolian sand layer
        4. Present morphology and processes
            a) Result of 3000 years of slowly rising sea level, limited sediment supply, and low wave energy
            b) 8 km of progradation at Cape Sable

VI. West Central Barrier System
    A. Very diverse with 29 islands and 30 tidal inlets
    B. A combination of wave dominated and mixed-energy features
    C. Sanibel Island deflection results from bedrock influence
    D. Strongly affected by hurricanes; open and close passes
    E. Three new barrier islands have formed since the early 1960s
        1. Three Rooker Island north of Honey Moon Island
        2. North Bunces Key and South Bunces Key near Bunces Pass
    F. Most barrier islands are 3-4,000 years old
    G. Sediment starve coast with materials resulting from reworking

VII. Marshy Coast of the Big Bend Area
    A. Plant dominated coast because
        1. Lack of siliciclastic sediments
        2. Low wave energy that reaches the coast
    B  . Broad flat shelf
    C. Karst influences topography and morphology
        1. Rectilinear creeks in joint patterns
        2. Larger scale depressions resulting from migration of springs
        3. Localized rock hubs

VIII. Panhandle Coast
    A. Apalachicola Delta is the sediment source; remainder of the area is a sediment sink
    B. Characterized by nearly continuous barrier islands
    C. Barriers often result from reworking
    D. Some progradation occurring
    E. Mostly wave dominated with E-W sediment drift