waves and energy Flashcards
how waves in the sea form
- as wind hits the water, ripples form, this is due to friction causing turbulence.
- then wind gets a even better grip and continues to push the ripples until they grow into large waves.
- energy is transferred from the air to the sea.
- kinetic energy through the water
- water is moving, but only in a circular motion.
what determines wave energy
- strength of the wind
- fetch
- duration- longer it blows the more powerful it is
why waves break
- waves start out at sea and have a circular orbit
- waves become shallower and the circular orbit of the water particles change to an elliptical shape. as approach the shore, friction slows the base of the wave, which is what causes it to become elliptical shape.
- the wavelength and the velocity both decrease and height of the wave increases, causing water to rise to a part where the wave starts to break.
- water rushes to the beach as swash and flows back as backwash.
explanation of a constructive wave, where made and what associated with
low,surging waves with a long wavelength.the small gentle waves spill over and constructs the beach as strong swash and weak backwash.
distant weather systems generate these waves in the open ocean. , more common in summer.
associated with a gentle beach profile, over time will build up beach and make it steeper.
ridge of sediment(berm) deposited by the wave. waves do not reach the foot of the cliff.
explanation of a destructive wave, where made and what associated with
high plunging waves, short wavelength. takes sediment away from the beach, due to having a weak swash and a stronger backwash. local storms are responsible for these waves. they are associated with a steeper beach profile although over time will flatten the beach.
the upper part of cliff attacked by spray and base of cliff attacked by breaking wave.little wave energy absorbed by the beach.
what are tides
changes in the water levels of seas and oceans caused by the gravitational pull of the moon, and to a lesser extent, the sun. UK coastline has two high tides and two low tides a day.
tidal range meaning , what affected by, hen highest and lowest,and what important for
relative difference in high and low tides.affected by the position of the sun and the moon, highest during spring tides and lowest during neap tides. a high tidal range creates relatively powerful tidal currents. important transfer mechanisms in transporting sediment either within coastal system or beyond. also important for determining precise height and duration of wave processes.
neap tide
moon at right angles to sun when in first or last quarter. gravitational pull acts against each other to create lower high tides and higher low tides.small tidal range.
spring tide
sun and moon in line at full moon or new moon. gravitational pulls act together to create higher high tides and lower low tides. largest tidal range
rip currents
strong localized underwater currents, commonly formed when a series of plunging waves cause a temporary build up of water at the top of the beach.met with resistance from the breaking waves the backwash is forced just below the surface following troughs and small undulations in the beach profile.
high energy coastlines
rocky coasts are generally found in high energy environments, this tends to be:
- where the rate of erosion exceeds the rate of deposition, e.g parts of Cornwall
- erosional land forms such as headlands, cliffs and wave cut platforms tend to be found.
low energy coastlines
sandy and est urine coasts indicative of low energy. tend to be:
1. where rate of deposition exceeds the rate of erosion.
2.stretches of coasts with less powerful waves, or sheltered from large waves
beaches, spits and coastal plains tend to be found in these environments.
