Geologic Hazards of Florida

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Geologic Hazards of Florida

• Karst terrain
• Flooding
• Sea level rise
• Earthquakes
• Unstable soils

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Karst Terrain

• acidic water dissolves limestone rock
• CO2 and N2 gases dissolve in rain
• acidity increases in the soil

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Why Limestone?

• Zones of weakness
• fractured
• laminated
• jointed
• units of differing textures

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Over time . . .

• cavities form and grow
• overlying rocks sediments collapse
• dry or disappearing streams
• eventually, land surface lowers on regional scale

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Flooding

• coastal areas, rivers, lakes
• coasts are highly developed and populated
• storm surges during hurricanes

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Flood relief projects

• drainage ditching
• river channelization
• storm water impoundments

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Flooding and El Niño

• flooding in Florida most common in winter of
  onset of El Niño
• Sir Gilbert Walker recognized relationships (1923)

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Sea level rise

• potential hazard of climate change
• any rise poses a threat because
• extensive coastlines
• major population centers along coast

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Protecting shoreline development

• sea walls and groins
• expensive
• temporary
• disruptive to natural beach ecosystem
• beach renourishment
• preserves the beach
• no increased erosion
• also expensive and temporary

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Implications

• 15 rise
• Everglades, Keys, Big Cyprus Swamp - under
  shallow sea
• new bays and estuaries
• new barrier islands
• 25 rise
• new bays may cut panhandle in many segments

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