Ch 4 Test

Question 1

what Generates forces of ocean waves

Answer 1

Wind, earthquakes (causing tsunamis) and landslides (including ice breaking off of glaciers)

Question 2

What do waves start as?

Answer 2

capillary waves aka ripples in the water

Question 3

As more energy is captured by the ocean what waves develop.

Answer 3

larger, or gravity waves

Question 4

Swells

Answer 4

Waves that have moved
out of their area of
origin. They have long
wavelengths, with
regular pattern of crests
and troughs. They have
large amount of energy
and lose it slowly.

Question 5

Tsunamis

Answer 5

series of waves,
generated in a body of
water by an impulsive
disturbance that
vertically displaces the
water column.

Question 6

Landslides

Answer 6

When a large piece of
land of glacier breaks
off and displaces the
water it falls into. When
the displaced water
comes back, the
movement causes a
series of waves.

Question 7

Wind speed

Answer 7

high wind speed, higher the
waves.

Question 8

Water depth

Answer 8

waves forms more easily in
shallow water.

Question 9

Fetch

Answer 9

the duration that the wind blows in
one direction.

Question 10

Three Factors of Wave Height

Answer 10

Wind speed, fetch and wind duration.

Question 11

Why would between 40 S and 50 S be considered the most favorable conditions for maximum wave formation?

Answer 11

Large areas of open ocean with little landmass
to interfere with fetch. Also, almost constant
westerly winds in the area add to duration.

Question 12

What are the two restoring forces of wave dissipation?

Answer 12

1. Surface tension restores capillary waves
2. Gravity restores the larger gravity waves.

Question 13

Waves

Answer 13

are energy that moves through the
water.

Question 14

Do waves transport water?

Answer 14

It does not move water
particles(transport water)

Question 15

Potential energy

Answer 15

energy stored in the height of the
wave.

Question 16

Kinetic energy

Answer 16

energy from the motion of the water
particles of the wave

Question 17

Orbital Waves

Answer 17

particles move in a circular
path.

Question 18

Crest –

Answer 18

highest point of a wave.

Question 19

Trough

Answer 19

– lowest point of a wave.

Question 20

Still Water level –

Answer 20

equilibrium

Question 21

Wave height(amplitude)

Answer 21

the vertical distance
from crest to trough.
Affected by wind speed, wind duration, and fetch

Question 22

Wavelength

Answer 22

the horizontal distance between
two consecutive crests.

Question 23

Wave period –

Answer 23

The time required for the wave
to crest at Point A to reach Point B

Question 24

Frequency

Answer 24

The number of wave crests
passing point A each second

Question 25

Wave Cancellation

Answer 25

Crest of one wave meets the trough of another. Wave energy is cancelled.

Question 26

Wave Reinforcement

Answer 26

Two crests or two troughs meet in sinc and add to increase the water height.

Question 27

Rogue Waves

Answer 27

Large waves that seem to appear out of nowhere and are unrelated to local sea conditions

Question 28

When do rouge waves occur

Answer 28

when various storm waves collide with each other reach near the edges of continental shelves and where there are constant wind, wave and current patterns.

Question 29

For deep-water waves, the wave must occur in water that is deeper than ___ the wave’s length.

Answer 29

1/2

Question 30

Do orbits reach the ocean floor?

Answer 30

The orbits do not reach the ocean floor

Question 31

For deep-water waves, the longer the wavelength, the _____ the wave travels.

Answer 31

faster

Question 32

What is the result of the orbits interacting with the seafloor?

Answer 32

As the wave approaches the shore, its orbit is affected by the bottom. The orbit becomes flattened (elliptical) and the forward speed of the wave is reduced because of friction.

Question 33

Water depth is less than ___ of the wavelength, a shallow-water wave begins to form.

Answer 33

1/20

Question 34

Surf Zone

Answer 34

- the area of the continental margin where waves release their energy

Question 35

As the speed slows, the wavelength ______ and the height _______.

Answer 35

shortens, increases

Question 36

What changes to wave height and wave speed would you expect as waves enter the shoaling zone? a. Both wave height and wave speed increase. * b. Both wave height and wave speed decrease. * c. Wave height increases while wave speed decreases. * d. Wave height decreases while wave speed increases

Answer 36

c. Wave height increases while wave speed decreases.

Question 37

spilling breakers

Answer 37

results in gently sloping ocean bottom. Losses energy more slowly than the others.

Question 38

plunging breakers

Answer 38

results in moderately steep ocean bottoms

Question 39

surging breaker

Answer 39

results from the ocean bottom having an abrupt slope. Energy is compressed into a short distance and waves break quickly.

Question 40

Sediment

Answer 40

As waves move down the shore, they move sand and sediment down a beach.

Question 41

Water

Answer 41

Water is moved along beach as well

Question 42

Rip Currents

Answer 42

Because of waves, water is transported towards the shore. Water then flows along the shoreline until it reaches an area where it can flow seaward again. These areas are usually narrow and distances apart. This leads to the formation of rip currents.

Question 43

Three Indicators of a Rip Current

Answer 43

1) turbid water and floating debris moving seaward. 2) areas of reduced wave height. 3) depressions in beach, perpendicular to shore.

Question 44

Rip currents are commonly observed on beaches with a _____ slope.

Answer 44

gentle

Question 45

tsunami

Answer 45

a wave train, or series of waves, generated in a body of water by an impulsive disturbance that vertically displaces the water column.

Question 46

Tsunamis are shallow water waves in all oceans. Why?

Answer 46

Depth of wave base is equal to roughly ½ the wavelength. Since most tsunamis wavelengths are about 125 miles, the ocean depth would have to be greater than 62 miles. There is no part of any ocean basin that is deeper than 62 miles. Example: Mariana Trench is only 7 miles deep.

Question 47

What is a tide?

Answer 47

The rise and fall of the sea, usually twice in each lunar day at a particular place due to the attraction between Earth and the moon and Earth and the sun.

Question 48

Interdial Zone

Answer 48

a marine ecosystem existing due to the rise and fall of the daily tides

Question 49

Lunar Day

Answer 49

24 hours and 50 minutes

Question 50

Why do the times for high tides and low tides in an area vary each day?

Answer 50

The Earth must rotate an extra 50 minutes to align directly with the Moon again.

Question 51

Monthly tidal cycle(lunar cycle) is _________

Answer 51

29 ½ days

Question 52

Diurnal tide

Answer 52

1__high tide; __1__ low tide each day. Common in shallow inland seas and bays.

Question 53

Semidiurnal tide

Answer 53

__2___ high tides; __2 low tides each day. Common Atlantic coast of the US, west coast of Africa

Question 54

Mixed tide

Answer 54

Usually: __2_ high tides; __2__ low tides each day.

Question 55

Minus tide

Answer 55

A low tide that falls below the mean average.

Question 56

A rising tide is called a—

Answer 56

flood tide

Question 57

A falling tide is called an

Answer 57

ebb tide

Question 58

When does slack water occur?

Answer 58

When tidal currents slow and reverse.

Question 59

Tidal bores

Answer 59

true tidal waves; Tidal bores usually form along shallow bays and river mouths because of the sharp change in water depth forces the rising tide at great speed against the out flow of river water.

Question 60

For a tidal bore to form, four main factor must exist:

Answer 60

#1 - Exceptionally high spring tidal range. * #2 - Shape of channel that grows narrow and shallow, upriver. * #3 – abrupt rise of flood tide but a long ebb tide phase. * #4 – low-lying river with a consistent seaward flow of water.