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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.

Regional Changes in Sea Level

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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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Page 1: Regional Changes in Sea Level

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.

Page 2: Regional Changes in 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

Page 3: Regional Changes in Sea Level

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.

Page 4: Regional Changes in Sea Level

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!

Page 5: Regional Changes in Sea Level

Satellite Altimetry

Page 6: Regional Changes in Sea Level

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.

Page 7: Regional Changes in Sea Level

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.

Page 8: Regional Changes in Sea Level

Predicted Future Impacts

Flooding and coastal inundation Loss of infrastructure Displacement of people Habitat and species loss

Page 9: Regional Changes in Sea Level

Flooding and Storm SurgesFlooding from rain storms and storm surges can overwhelm current drainage infrastructure.Could cause serious damage to existing infrastructure.

Page 10: Regional Changes in Sea Level

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

Page 11: Regional Changes in Sea Level

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).

Page 12: Regional Changes in Sea Level

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.

Page 13: Regional Changes in Sea Level

Plants Threatened by Sea Level Rise

Johnson’s SeagrassAmerican Toadwood

Sea Rosemary

Coralberry Smallflower Lilythorn Beach Sunflower

Page 14: Regional Changes in Sea Level

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

Page 15: Regional Changes in Sea Level

Effects on Animals

Habitat degradation and fragmentation

Local extinctions Global extinctions Human-animal conflicts

Page 16: Regional Changes in Sea Level

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

Page 17: Regional Changes in Sea Level

Habitat Fragmentation

Page 18: Regional Changes in Sea Level

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