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Regional Changes in Sea Level. Oceanographic factors O cean circulation (Atlantic Ocean vs. Gulf of Mexico) Atmospheric pressure Vertical land movements Tectonics - PowerPoint PPT Presentation
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Regional Changes in Sea Level
Oceanographic factors Ocean circulation (Atlantic Ocean vs. Gulf of Mexico) Atmospheric pressure
Vertical land movements Tectonics Tectonic plates are rising and falling in different parts of the world from
the weight of past glaciers (Glacial isostatic adjustment) Subsidence and sedimentation
These changes do not alter ocean volume, but they change the shape and volume of ocean basins, affecting global mean sea level.
Measuring Sea Level: Tide Gauges
The longest running tide gauge is in San Francisco, CA dating back June 30, 1854.
The tide was measured using a float inside a stilling well.
The tide staff allowed scientists to manually measure sea level and compare it to the readings taken by the analog recording device (ADR) inside the tide house.
The tide was continually recorded using ink and a paper strip and was collected monthly.
Problems: Recording errors Marine fouling Maintenance Data processing time
Measuring Sea Level:Tide Gauges
Newer tide houses use an acoustic sounding tube to measure the tide, replacing the stilling well with a float.
Very accurate. Minimal maintenance. Also records wind speed and
direction, water current speed and direction, air and water temperature, and barometric pressure.
Data is sent to NOAA headquarters every hour using satellite transmissions.
Satellite Altimetry
Satellite altimetry data shows a rate of sea level rise at 3.3mm/year or 1.6 inches from 1st grade to 12th grade!
Satellite Altimetry
Impacts Already Being Felt
Flooding during high tide Compromised flood control structures
Saltwater intrusion on drinking water sources Well fields Porous limestone structure (can’t build sea wall) Movement of saltwater beneath freshwater tables
Landward migration of freshwater wetlands that may experience peat collapse along the coast Saltwater intrusion → plant mortality → peat collapse →
permanently flooded area.
Bruun Rule
For every foot of sea level rise, the amount of land that is inundated ranges from an average of 100 feet in the United States to as much as 1000 feet in Florida.
Predicted Future Impacts
Flooding and coastal inundation Loss of infrastructure Displacement of people Habitat and species loss
Flooding and Storm SurgesFlooding from rain storms and storm surges can overwhelm current drainage infrastructure.Could cause serious damage to existing infrastructure.
Human Displacement
Vulnerability of People and Land Under 4 ft. 2.4 million people 107 towns and cities 1.8 million acres of
land Most Vulnerable Cities:
#1 Miami #7 Tampa
Sea Level Rise Predictions
The Florida Keys and much of south Florida will be completely inundated by a rise 2.0 meters of sea level rise (about 6.5 feet).
Effects on Plants
Most plants can not tolerate saltwater of any kind.
Plants that are exposed to saltwater due to sea level rise will die and many species will become extinct.
Some plants have developed adaptations to getting rid of salt.
Plants Threatened by Sea Level Rise
Johnson’s SeagrassAmerican Toadwood
Sea Rosemary
Coralberry Smallflower Lilythorn Beach Sunflower
Mangroves
Red Mangrove, Black Mangrove, and White Mangrove.
Provide coastal stability Can tolerate saline conditions of
estuaries and intertidal zones, but not seawater
In some parts of Florida they cant keep up with the rate of sea level rise and they are disappearing.
Used as nurseries for fish, crustaceans, and mollusks
Roosts and rookies for coastal birds
Food source for fishes, shrimp, and claims
Effects on Animals
Habitat degradation and fragmentation
Local extinctions Global extinctions Human-animal conflicts
Animals Threatened By Sea Level Rise
Diamondback Terrapin Key Deer
Peninsular Ribbon Snake
Lower Keys Marsh Rabbit
Mangrove Cuckoo
Florida Panther Loggerhead Sea Turtle
Striped Newt
Short Tailed Hawk
Short Tailed Shrew
Okaloosa Darter Fish
American Crocodile
Habitat Fragmentation
What Factors Make a Species Vulnerable?
Habitat inundation Erosion of substrate Barriers of movement Dependence on habitat
climate Salinity tolerance Storm surge and runoff
tolerance
Biotic interactions Dispersal ability Variation in traits Genetic diversity Adaptive rate Population Size