Exam 2 Flashcards
Shallow water wave
L>20d
Square root of (gravity)(Depth)
Deep Water wave
L
Energy flux is equal to?
(Amount of energy) times (Speed of energy(
Individual waves move with?
Phase speed (C)
Group of waves move with?
Group velocity (Cb)
Wave size is dependent on?
Wind Speed
Duration
Fetch
Capillary waves
L
Gravity waves
L>1.7cm
Define a “Fully developed sea”
If fetch and duration are large enough, equilibrium is reached where energy in=Energy out. The waves are at the maximum height for that wind speed.
OR
A fully developed sea is the state where the wind is giving the sea the same amount of energy that the sea is dissipating.
As swells travel, its wave height diminishes due to..?
Attenuation
Spreading loss
Standing Wave (Seiche)
The sum of 2 waves traveling in opposite directions.
Node (Seiche)
No change in water level, horizontal motion.
Antinode (Seiche)
Vertical motion
Tsunami’s Reaching Shore: Is energy flux conserved or no?
Energy flux is conserved
Speed of energy x Amount of energy
When depth quickly decreases, Height quickly increases
Continuity in 1-direction
Mass in/Time=Mass out/Time
East-West velocity
du/dx
=(U2-U1)/(X2-X1)
North-South velocity
dv/dy
=(V2-V1)/(Y2-Y1)
Quadrature
7 Days
Opposition
14 Days
Quadratrue
21 Days
The Harmonic method
The observed tide is the sum of many different harmonics, or partial tides.
Each harmonic corresponds to some component of Earth-sun-moon motion.
Stable
Unstable
Stable: E is positive, the larger the number, the more stable the water is.
Un-stable: E is negative, short-lived.
Diurnal
F>3
Semi-diurnal
F
Wave energy
(1/8)(rho)(g)(H)^2
