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Waves: wind-sculpted water
surface, sinusoidal; the wave form moves, NOT the water
waves (wind-made)
vs tides (moon-made) vs deep ocean currents (sun-made)
waves produced
by wind-water interaction, drag on surface of water by wind
unidirectional motion of wave form vs circular motion of water; waves
at
depth
parts of the
wave; wavelength, wave height (amplitude), wave velocity, shape
earthquake-generated
"tidal" waves or tsunamis; enormous wavelength, high velocity
Wave-Shore Interaction:
waves
change their shape and movement in shallow water
shoaling of waves
on bottom; changes in amplitude, wavelength, water motion
breaking waves,
surf zone, swash zone; energy expenditure; sediment abrasion
oblique waves
and longshore drift of water and sediment parallel to the shoreline
special type of longshore current not produced by sun (see below)
wave refraction
(bending) and reflection (bouncing), wave interference
Rocky Shorelines (Erosional
Beaches):
northern Washington coast, e.g.
rocky headlands
and wave refraction (energy concentration); arches, seastacks
wave cut
platforms
in solid rock; coastal uplift and formation of marine terraces
Sediment: beach sediment
varies a lot depending upon energy, source materials, etc.
production of
beach sediment from rocky headlands; abrasion, water wedging, etc.
other sediment sources: rivers, landslides onto beach, biogenic sediment
sediment on
beaches;
cobble versus sand beaches, coral beaches, black sand, green sand
Longshore Drift/Transport of
Sediment:
very important process found on most shores
oblique waves
produce longshore transport of sediment; where's my beach blanket?
transport rates
and volumes: examples from the Washington coast
associated
landforms
like sand spits, curved spits and hooks, baymouth bars, tombolos
redistribution
of sediment; case histories (Ocean Shores, Cape Shoalwater, etc.)
Depositional Beaches:
sediment
accumulating into large deposits. Ocean Shores, e.g.
parts of the
beach; summer and winter berms, beach face, offshore bars
changes in
beaches
from summer to winter; wave energy and sediment distribution
barrier islands
e.g. North and South Carolina, offshore sand bars
mixed
environments:
marine deltas, marine estuaries, lagoons, mangrove swamps
Beaches and Humans:
beaches
are NOT permanent, they are temporary, ephemeral
Human
interference:
effects of jetties/groins, breakwaters, etc. on longshore transport
case histories: New Jersey shore, Santa Barbara, Santa Monica,
Grays
Harbor
Shoreline
armoring:
retaining walls and bulkheads, effects on sediment and life
Human habitation
of beach environments: Washaway Beach, Point Chehalis
Dams and sediment
supply to beaches, beach erosion; clearcutting and sediment.
Sea level changes
and glaciation, emergent and drowned coastlines, fjords
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