Oceanography Test 3 Ch.8

Describe the Krakatau volcanic disaster

-36000 people died -35m

Describe the motion of longitudinal waves

-Longitudinal waves are also known as push-pull waves -The particles push and pull in the same direction that the energy is traveling; similar to a spring

Describe the motion of orbital waves

-Orbital waves are also known as interface waves -The movement involves both transverse and longitudinal, so particles move in circular orbits -Found at the oceans surface

Describe the motion of transverse waves

-Transverse waves are also known as side to side waves -The energy travels at right ables to the direction of the vibrating particles

Wave steepness and its formula

-Wave steepness is the ratio of wave height to wavelength Wave Steepness = H/L

Describe spilling breakers

-gently sloping sea floor -wave energy expended over longer distance -water slides down front slope of wave -white foam -most common

Describe plunging breakers

-moderately steep sea floor -best for surfing -curling wave crest releases energy instantaneously

Describe surging breakers

-very steep sea floor -energy expended over shortest distance -waves break on the shore

As deep water waves approach shore and become a shallow water wave what physical changes occur

-wave speed decreases -wavelength increases -wave height increases -wave steepness increases -when steepness reaches 1/7 the wave breaks

Name and describe the three interfaces fluids travel on to create waves

1. Air-Water: the movement of air across the ocean surface; creates ocean waves 2. Air-Air: the movement of different air masses; creates atmospheric waves 3. Water-Water: the movement of water of different densities; creates internal waves; associated with a pycnocline

List and describe the three wave interference patterns

1. Constructive Interference: in phase wave trains with the same wavelength 2. Destructive Interference: out of phase wave trains with the same wavelength 3. Mixed Interference: two swells with different wavelengths and different wave heights

List the three types of breakers in the surf zone

1. Spilling 2. Plunging 3. Surging

Name the three factors affecting wave energy

1. Wind speed 2. Wind duration 3. Fetch -waves will continue to grow until one of these is limiting

Wave train speed is

1/2 speed of an individual wave in the group

What wave steepness will cause a wave to break

A wave will break if the wave steepness exceeds 1/7

As waves come into shallow water, their physical characteristics change, waves gets slower, higher, and steeper, which cause waves to ___ in the surf zone.

As waves come into shallow water, their physical characteristics change, waves gets slower, higher, and steeper, which cause waves to break in the surf zone.

Wind generates stress on the sea surface and are commonly called ripples

Capillary waves

Causes of water displacement and tsunamis

Earthquakes (most common) Volcanic explosions Landslides Meteorite impacts (least common)

The distance over which wind blows

Fetch

For ocean waves, the larger the amplitude, the greater the

For ocean waves, the larger the amplitude, the greater the energy

For ocean waves, the longer the wavelength, the greater the

For ocean waves, the longer the wavelength, the greater the energy of the wave and the faster the wave travels

The number of wave crests passing a fixed location per unit of time and is the inverse of the period

Frequency, f

When waves can no longer grow because of an equilibrium condition called

Fully developed sea

Symmetric waves that increase with wave energy and begin to take on a rougher appearance

Gravity waves

Indonesian Boxing Day Earthquake 2004, what was the wavelength?

L was 500 km (~300 miles)

Most waves are generated by ___ which produce wave energy that is transmitted across entire ocean basins; as a wave passes, it causes the water to go around in a ___ orbit.

Most waves are generated by storms which produce wave energy that is transmitted across entire ocean basins; as a wave passes, it causes the water to go around in a circular orbit.

How do progressive waves move?

Progressive waves oscillate uniformly and travel without breaking

Formula for wave velocity/speed

S=L/T

Water becoming gradually more shallow

Shoaling water

Zone of breaking waves near shore

Surf zone

Uniform, symmetrical waves originating from sea area

Swell

Describes the appearance of sea surface

The Beaufort Wind Scale describes the appearance of the sea surface

The energy that causes ocean waves to form is called

The energy that causes ocean waves to form is called disturbing force

The shape of a wave is called

The shape of a wave is called the waveform

The three types of progressive waves are

The three types of progressive waves are: 1. Longitudinal 2. Transverse 3. Orbital

Name the three types of wind generated waves

The three types of wind generated waves are 1. Capillary Waves 2. Gravity Waves 3. Trochoidal Waves

How are internal waves created?

Tides, turbidity currents, wind, and ships create internal waves

When the wave crests become pointed and the troughs become rounded and energy is continuously increasing

Trochoidal waves

Tsunami are fast and long waves generated by ___ events such as underwater fault movement; their alternating surges and withdrawals at the coast are often very destructive.

Tsunami are fast and long waves generated by seismic events such as underwater fault movement; their alternating surges and withdrawals at the coast are often very destructive.

The sorting of waves by wavelengths

Wave dispersion

Wave height is directly related to wave ___ Wave heights are usually less than ___ meters

Wave height is directly related to wave energy Wave heights are usually less than 2 meters

The vertical distance between a crest and a trough

Wave height, H

The time it takes one full wave -one wavelength- to pass a fixed position

Wave period, T

Wave reflection at an angle can create higher or lower crests through ___

Wave reflection at an angle can create higher or lower crests through interference

Changes in velocity across a wave front due to differences in seafloor depth

Wave refraction

Wave refraction concentrates energy at ___ and spreads out energy at ___

Wave refraction concentrates energy at headlands and spreads out energy at bays

Wave speed in deep water depends only on

Wave speed in deep water depends only on wavelength

Wave speed in transitional depth water depends on

Wave speed in transitional depth water depends on the water depth and wavelength

The rate at which a wave travels

Wave speed, S

A group of waves with similar characteristics where the front wave is continually dying out

Wave train

The horizontal distance between any two corresponding points such as crest to crest

Wavelength, L

Waves in which depth d is less than 1/20 of the wavelength L/20 are called

Waves in which depth d is less than 1/20 of the wavelength L/20 are called shallow water waves or long waves

The tallest wave height was how tall and discovered by

While caught in a Pacific typhoon, the USS Ramapo measured a wave 112 feet high or 34 meters

Where wind driven waves are generated

Wind driven waves are generated in the sea area

The speed of shallow water waves is influenced only by

and water depth, d

Wave speed is also known as

celerity, C

As the wave travels, the water passes the energy along by moving in a circle. This movement is called

circular orbital motion

The high parts of waves are called

crests

If the water depth (d) is greater than the wave base (L/2), the waves are called

deep water waves

Include all wind generated waves in the open ocean and have no interference with the ocean bottom

deep water waves

when the trough of the wave arrives first on shore

drawdown

A tsunami's wavelength is

greater than 200 km

Waves with longer wavelengths travel faster and thus

leave the sea area first

A ___ may make lake levels rise and fall repeatedly and rapidly at various points

seiche

Standing waves in enclosed or semi-enclosed basins are called

seiches

Produced when waves are reflected at right angles to a barrier

standing waves -sloshing water in a bathtub -no net movement -no vertical motion at nodes -no horizontal motion at antinodes

Swell from distant storms is called

surf

Uniform, symmetrical waves that travel outward from storm areas -have long crests -can transport energy long distances

swell

A tsunami that travels across an entire ocean basin is called

teletsunami

When deep water waves encounter shoaling water less than 1/2 their wavelength, they become

transitional waves

The low parts of waves are called

troughs

Powerful, destructive waves generated by the displacement of a large volume of water

tsunami

Causes of shallow water waves include

tsunamis, tides

Th depth below the surface of the ocean where circular orbital motion dies out is called

wave base wave base is equal to L/2

a way to move energy along an interface between two substances or layers of a substance

waves

When waves reach their critical steepness, ___ form

whitecaps