ocn 5401 chapter 11 coastal ocean instructor: dr. george a. maul [email protected] / x 7453
TRANSCRIPT
Earth’s Estuaries
Estuary ClassificationsKnauss Nybakken Sumich Kennett
Salt Wedge Coastal Plain Coastal Plain Salt Wedge
Partially Mixed Tectonic Bar Built Partially Mixed
Well Mixed Fjord Delta Lagoon
Negative Delta
Estuaries and Inlets
Estuarine Issues
Mixing
Richardson Number
Ri < 0.25 internal shear waves develop
𝜒=𝑣𝑜𝑙𝑢𝑚𝑒𝑡𝑟𝑎𝑛𝑠𝑝𝑜𝑟𝑡=𝑚3
𝑠
Residence Time (t)
and
Sebastian Inlet
Coastal Ocean Observing System
Coasts and Beaches
A healthy coral reef
creates sand for healthy
beaches
Beach Terminology and Sand
D(mm) Wentworth Grade Phi
>256 Boulder -8
>64 Cobble -6
>4 Pebble -2
>1 Very course sand 0
>1/2 Course sand 1
>1/4 Medium sand 2
>1/8 Fine sand 3
Beach Sand Erosion and Accretion
h𝑤𝑇
>2⇒𝐸𝑟𝑜𝑠𝑖𝑜𝑛h𝑤𝑇
<2⇒ 𝐴𝑐𝑐𝑟𝑒𝑡𝑖𝑜𝑛
h=𝑤𝑎𝑣𝑒h h𝑒𝑖𝑔 𝑡 ,𝑤=𝑆𝑡𝑜𝑘𝑒𝑠 𝑣𝑒𝑙𝑜𝑐𝑖𝑡𝑦 ,𝑇=𝑤𝑎𝑣𝑒𝑝𝑒𝑟𝑖𝑜𝑑
Short period wind waves(T<7 seconds)
Long period swell waves(T>9 seconds)
Classification of River Deltas
Brazos River Delta Ganges River Delta
Amazon Delta
6300 km3/year
~ 1/150 of Gulf Stream
The drainage basin of the Mississippi River encompasses a major portion of the central United States.
How much is this??
The Mississippi River has built a series of overlapping subdeltas as it continually dumps sediment into the Gulf of Mexico.
Satellite Imagery of the Classical Birdsfoot Delta at the mouth of the
Mississippi River
Mississippi River entering Gulf of Mexico - Note the color contrast.
(Picture from John Trefry)
Changes in sediment composition along the Nile River
Nile Delta Sediments
Denial is not a river in Egypt Photograph
False color Image
Semi-Enclosed Seas
Intra-Americas Sea
Intra-Americas Sea SSH http://www7320.nrlssc.navy.mil/GLBhycom1-12/navo/intramssh_nowcast_anim365d.gif
Lakes – The Aral Sea
Artificial Lakes
Lake Nasser
Coastal Ocean of the
Southeastern United States
OCN 5401
Questions?
Chapter 11