Coasts Geography

• • coasts are a zone where the land meets and interacts with the sea
• coasts are a result of interactions between the land, water, air (weather, rainfall, oxygen) and living things (the 4 spheres)
• The submerged zone  below the low tide shoreline is offshore.
•  Between the low tide and high tide shorelines is the  foreshore.
• The backshore stretches landward from the high tide shoreline to the highest water line.
• A berm is a elevated bump of sand that the hightide deposits sand at the highest water line
• The factors that affect coasts are waves, tides and seal level changes, ocean currents, geology, types of ecosystems and human activities
• A wave is a rising and falling  movement of the water surface that is usually produced by winds blowing across the sea or ocean.
• Energy from the wind is transferred to the water and it is this wind energy that helps shape coasts  when the waves hit land.  
• distance between crests is known as wavelengths
• waves do not move at the same speed
• constructive interference can cause two waves, which catch up with one another wave can cause bigger waves
• destructive waves have more energy than constructive waves
• energy from the motion of air molecules is transferred to the shore because of friction and pressure (wind driven waves)
• gravity can affect waves to swell called tidal swell
• Tides refer to the daily alternate rise and fall in the sea level.
• Tides are caused by mainly by the effects  of the gravitational pull of the moon and sun on the earth.  
• Tides affect processes such as coastal erosion, sediment transport and sediment deposition.
• During  high tides, waves reach parts of coasts that may not be subjected to wave action at low tides. Hence, at high tides, waves erode and transport more sediments away from larger parts of the coasts than  at other times.  
• tides can deposit matter on the shore to create objects like the sand, or like rocks take for example the 12 Apostles → constructive waves
• Currents are large-scale, continuous movements of water in seas and oceans.
• Currents are produced  by a combination of winds, the Coriolis effect, water density and temperature differences in the  ocean.
• As the currents approach the coast, they are able to cause the movement of sediments along  the coast.  
• ocean currents can shape the microclimate → the climate that affects only a very small area/ of the coastal area
• Ocean currents carry cool water away from the North and South Poles towards the Equator and warm water away from the Equator towards the poles. In this way, ocean currents help create milder  climates in coastal environments. 
• geology is the arrangement and composition of  rock found in the area.  
• Rock composition determines the hardness of rocks and their resistance to erosion, which affects  the rate of change along coasts. More resistant rocks such as granite and basalt will erode more  slowly than less resistant rocks such as limestone and shale.  
• Coastal processes that operate on coasts consisting of different types of rock result in coasts with  different coastlines. A coastline is the outline or contour of a coast.  
• well joined rocks offer more lines of weaknesses to erosional processes → kind of like flaws?
• when the ocean attacks the lines of weaknesses, it will causes the rock to weaken and eventually break off. the higher the number of lines of weaknesses, the higher the rate of causes it to change and destruction of the rock
• coastal environments are ever changing are are dynamic
• The crest is the highest part of a wave, while the lowest part of a wave is the trough.
•  Wave height: the vertical distance between the crest and the trough. (lowest point).
• Wavelength: the horizontal distance from crest to crest or from trough to trough.
• ave steepness is the ratio of wave height to wavelength (height / wavelength).
• Wave period: the time waves take to travel through one wavelength
• Wave frequency: the number of wave crests or troughs that pass a fixed point in one second. 
• waves develop energy from the wind blowing across seas and oceans is transferred to the water's surface
• waves shapes the different landforms along the coast
• seabed interrupts the circular orbital movement of water