How many oceans and ocean basins does earth's surface have? - Answers one ocean
5 basins - artic, atlantic, indian, pacific, southern
what is the difference between the surface current and waves - Answers surface current - large
permanent winds that blow over the ocean create surface currents that transport matter and energy
waves - occasional winds that blow over smaller areas ---> transport energy only
Crest
Trough
Wavelength
Waveheight
amplitude
Period
Frequency
celerity
steepenss - Answers -top of wave
-bottom of wave
- top - top/ crest=crest
-crest to trough
- sea level to trough or crest
- time/cycle
- cycles /sec
-speed m/s
- peakedness of wave, ratio of height to wavelength H/L
Wave height of waves is related to - Answers energy transported by waves
- applies only to deep-water waves
,Does the energy generated by wind waves equal to more than the waves generated by
earthquakes/storms/gravitational attraction etc - Answers - wind waves can carry more energy at one
instance
- but the total amount of energy over time is greater in earrthquakes etc.
What are the two ways of classifying waves - Answers 1. generating/disturbing force
- waves are classified according to the force that generates the waves
- wind - wind wave
- changes in atmospheric pressure, storm surge, tsunami - seiche
- seismic activity, landslide - tsunami
- gravitational attraction - tide
2. Restoring Force
- classified according to their restoring force --> force that causes water to return to undisturbed state
- surface tension --> capillary wave
- gravity - surface gravity waves (wind wave, seiche, tsunami, tide)
Capillary waves - Answers - tiny waves with tiny wavelengths
- waves restored by surface tension
- generated when wind blows
sea state
- depends on what 3 factors
- types of waves - Answers an assessment of the ocean's conditions of the ocean surface
- depends on 3 factors:
1. wind strength/speed
2. fetch
3. wind duration ( length of time wind blowing over fetch)
, - when wind blows over a fetch waves are transformed in this order:
- cappilary waves --> ripples --> chop --> swells
When is a fetch fully developed - Answers - once it has absorbed the max amount of energy it can
contain
- includes chaotic waves of varying heights/lengths/speed/direction where MAXIMUM HEIGHT is
achieved for a given wind
What happens to waves as they move away from the fetch? - Answers - they become well sorted with
long waves leading the wave train
- swells
- sorted by speed and wavelengths
- fastest/ longest wavelengths leave first
- slowest/shortest wavelengths leave last
- swells propagate away from fetch in groups called wave trains
What parameters do you need to determine when a fetch is fully developed - Answers - x axis = duration
- y axis - fetch (km)
- slope = wind speed
- can determine distance of fetch, wind speed, and duration needed to create fully developed sea where
max height is achieved
Significant wave height
- what
- how to estimate - Answers the average height of the highest one-third of the waves present
- avg number so we can encounter waves whose max wave height is 2x the significant wave height**
- estimating:
1. list all wave heights observed from tall to short