Coasts Flashcards
what 2 things work together at a coast
lithosphere and hydrosphere
what is the lithosphere
crust and uppermost mantle continuing the hardened rigid over layer of the Earth
what is the hydrosphere
Layer of water near the earths surface
what is input
what arrives in a system
what is output
what leaves the system and moves across boundaries
what do boundaries do
separate areas of coastline
what’s part of input in costal open system
sediment carried by river and waves, wind generated waves, precipitation
what takes place an output in open costal system
eroded material taken out to sea, ocean currents and evaporation
what takes place in transfers in the open coastal system?
transportation processes, longshore drift mass movement, wind blow blown sand
What takes place in the stores part of the open coastal system?
beaches
cliffs
dunes
what is dynamic equilibrium
State of balance where inputs are equal to outputs in a system that is constantly changing
what is feedback?
Automatic response to a change with an system
what is positive feedback?
Leads to further change for example, increasing wave energy could scour the sea bed deepening water allowing more wave energy to enter location increasing wave energy further
What is negative feedback?
Reduces the effective change for example decrease and wave energy entering the coast zone could lead to deposition of sediment offshore further reducing wave energy as it’s lost a friction
What is a landform?
Geographic feature on the surface of the Earth
what is landscape
part of the Earth surface
what is the fetch of a wave
the distance that the wind blows across water
what is the swash of a wave
movement of water up the beach
what is the backwash of a wave
movement of water down the beach
what is the crest of a wave
top of a wave
what is the trough
bottom of wave
what is wavelength
Distance between two crests or two troughs
what is velocity
The speed that wave is travelling it is influenced by the wind fetch and depth of water
wave frequency
How many waves there are per minute?
What is wave refraction?
the bending of waves as they approach a coastline at an angle, caused by the slowing down of the wave as it enters shallower water, leading to a redistribution of wave energy along the coast
what happens when waves diverge
loose power and drop sediment
wave energy becomes concentrated on headland causing greater erosion and features
.
what are rip currents
Strong, localised underwater currents that occur on some beaches posing danger, swimmers and surfers. They are found in a series of plunging waves cause a temporary buildup water at the top of the beach.
What is the current?
The permanent or seasonal movement of surface water in sea is in oceans
what is upwelling
is an oceanographic phenomenon where wind-driven motion causes dense, cooler, and nutrient-rich water from deep ocean layers to rise towards the surface, replacing warmer, nutrient-depleted surface water.
what is a tide
Periodic rise and fall of the level of sea in repo to the gravitational puddle of the Sun around the moon
what are the causes of tides?
moon pulling water
What are spring tides?
Twice in a lunar month when the sun moon and earth are in a straight line, the tide raising force is as as lowest point producing highest monthly tide
what are neap tides?
twice a month for the Moon and son are positioned at 90° in relation to the Earth. This alignment gives the lowest monthly title ranges called tides gravitational pull is less effective.
