Regional Changes in Sea Level

heehawultraMechanics

Feb 22, 2014 (3 years and 3 months ago)

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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


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 1
st

grade to 12
th

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 Surges


Flooding

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
Seagrass

American
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

E
ffects 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