Alat, Alon, at Hangin (part 5) Flashcards
Result of forces acting on the surface of the water
waves
Does not represent a flow of water but a flow of energy or
motion
waves
occurs when the crest of one wave meets the
trough of another, and the sea surface ends up intermediate between the two
wave cancellation
If the crests of two waves collide, however, they add together to produce a higher wave
wave reinforcement
occasionally produces rogue waves as tall as a 10-
story building that seem to come up out of nowhere
wave reinforcements
A force that disturbs the water’s surface, such as a stone dropped into the water or wind blowing across the water’s surface, is called a
generating force.
The raised surface then falls back down and creates a depression in the surface
depression
The force that causes the water to return to the undisturbed level is called the
restoring force
Small waves are referred to as
capillary waves
When the amount of water displaced is sizable, the restoring force is gravity and the waves are referred to as
gravity waves
results from the interactions between generating forces and restoring forces
wave
wavelength of capillary waves
< 1.73 cm
wavelength of gravity waves
> 1.73 cm
formed by local storm centers or by the prevailing winds of the wind belts,
(trade winds or westerlies)
progressive wave
As wind waves are formed by the storm, they are forced to increase in size and speed by the input of energy from the storm;
forced waves
When the energy from a storm or other generating force no longer has an effect on the waves, they become
free waves
long-period, uniform waves are called
Swells
While the wind is blowing it pushes the wave
crests up into sharp peaks and “stretches out”
the troughs. Waves like this are called _
seas
have smoothly rounded crests and
troughs, and very similar to the ideal waves
swells
Eventually swell become so high and so steep
that they fall forward and break, creating __
surf
Waves that occur in water that is deeper than one half of a wave’s wavelength are called _
deep-water waves
If the wind speed is low, the waves will be __, regardless of the duration or the fetch.
small
True or False:
A strong wind blowing for a short time does not produce large waves even if the fetch is large.
True
If a strong wind blows for a long time over a short fetch, the waves are _.
small
Large waves are produced only when all three factors are of HIGH MAGNITUDE. What are the 3 factors?
(windspeed, wind duration, and fetch)
When a deep-water wave enters shallow water it becomes a _
shallow-water wave
depth of the water is less than half the
wavelength
shallow-water wave
the area along a coast where waves slow down,
become steeper, break, and disappear.
surf zone
form in the surf zone when the bottom of the wave
slows but its crest continues moving toward the shore at a speed faster than that of the wave.
breakers
two most common types of breakers
plungers and spillers
form when the beach slope is steep
crest curls and curves over and outruns the rest of the
wave.
Plunging breakers
more common and are found on
flatter beaches, where the energy is dissipated more
gradually as the wave moves over the shallow bottom
Spilling breakers
last longer than plungers because they lose energy more
gradually
Spilling breakers
Sudden movements of the earth’s crust produce earthquakes,
which may produce large seismic sea waves, or _
tsunamis
The sudden increase in energy causes the height of the wave to
increase dramatically, and the energy rapidly dissipates as the
water races over the land mass
Tsunamis
The periodic changes in water level
that occur along coast lines are called
Tides
Result of the gravitational pull exerted
on the water of the oceans by the
moon and the sun
tides
An opposing _ pulls the
center of mass of the earth–moon
system away from the sun.
centrifugal force
For the earth–moon system to remain
in orbit around the sun, the
__ must equal the
centrifugal force.
gravitational force
- Full tidal cycle takes
24 hours and 50
minutes
only one
high tide and one low tide each day.
diurnal tide
*Two high tides and two low tides each day
semidiurnal tide
*the two high tides are the same height and the two low
tides are at about the same level
semidiurnal tide
*If the high and low tides are at different levels, it is referred to as
mixed semidiurnal tides
_ the greatest height to which the high tide rises and the lowest point is called _.
greatest height - high water
lowest height - low water
Rising tide is a
FLOOD TIDE
Falling tide is an
EBB TIDE
