Waves and Tides

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Waves and Tides
Wave movement and properties Wind and
waves Waves and beaches Making a tide Tide
theory Tides and basins, shores
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Wave movement
Longitudinal waves E transmission in same
direction Transverse waves E transmission is
perpendicular Orbital waves E transmission
across interface Height H Wavelength L Steepness
H/L Period T Speed S L/T Lf
gT/2? Frequency f 1/T Depth L/2 Shallow
waves D lt L/20 S ?(gD) 3.1?(Dm)
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Wind and Waves
Wind-generated waves Capillary waves (ripples) L
lt 1.74 cm Gravity waves L gt 1.74 cm Sea where
wind generates waves Steepness 1/7 whitecaps
energy loss fully-developed Wave trains and
interference Rogue waves
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Surf
Swell releases E at surf zone If local waves
rough, uneven surf Wave drags bottom
L H break Circular oscillation
outrun wave plunging breakers turbulent water,
air spilling breakers (gentle slope)
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Waves and Beaches
Refraction Waves bend around objects Reflection/
diffraction Waves reflect off objects
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Waves and Beaches
Storm surge Tsunamis
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Tides
Gravity, distance important Gravity g
(m1m2)/r2 Tidal force ? (m1m2)/r3 Simple
model moon above equator, no earth tilt
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Tides 2 Variables
elliptical orbit of earth, moon
declination of moon
tilt of earth
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Tides 3 Land Water
Amphidromic points
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Tides and Geomorphology
Bays, gulfs geomorphic features effect Open
ocean amphidromic point Coriolis
force Reversed and ebb currents Tidal bores

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Waves, Tides, and Organisms
Waves high energy, turbidity in surf zone --gt
Stabilization, damage resistance, feeding Tides
change in H2O P, depth, salinity, T
nearshore Daily effects feeding,
activity Annual effects timing of breeding,
recruitment