Geography Revision

Glossary, materials and more

Coastal zone = Where the land meets the ocean/seaOcean = A very large expanse of sea (salt water) that covers 75% of the Earth’s surface and divided into 5 main areasWaves = Are caused by the wind dragging on the surface Fetch = Distance of the ocean over which the wind has blownDestructive waves = Have steep gradient waves, tall waves with short wavelength, weak swash, strong backwashConstructive = Long wavelength, shallow gradient waves, strong swash, weak backwashHigh Tide = Tide at its highest levelLow Tide = Tide at its lowest levelTidal range = The difference between high and low tideErosion = The process by which rocks and soils and materials are worn down and moved elsewhere due to mechanical and chemical action - Hydraulic Action = The force of the water hitting the cliffs and compressing air into small cracks causing the rock to weaken and break apart - Abrasion = The hurling of rocks at the cliff face; this is like a sandpaper action - Attrition = Rocks hit against each other in the wave to leave smooth, rounded pebbles - Solution = Acidic sea water dissolves any minerals in the cliff face Weathering = The process by which rocks and materials are broken down in situ (does not involve movement) due to biological and weather processes e.g. rain, wind ice etc - Chemical = Rain is slightly acidic. That's because it dissolves CO₂ (carbon dioxide) from the air. So, it reacts with limestone and dissolves it away - Biological = Roots work their way into cracks in rocks, and widen them. Burrowing animals also make cracks bigger - Mechanical/Physical = At 0°C, water freezes in cracks. It expands as it freezes, so cracks get wider. This happens again and again until the rock eventually falls apart

the ocean provides an important source of protein

provides substantial amount of oxygen

phytoplankton in the ocean (provides oxygen)

produces carbon dioxide (CO₂)

animal species - biodiversity life began from the oceans

life would not exist without oceans

the water cycle

used for hobbies, relaxation and calmness

provides food for developing nations

Why are coasts and oceans so important?

1 Waves are created when the wind blows over the sea2 Water within a wave moves in a circular motion3 As the wave nears land its lower part is slowed by friction with the sea bed4 The top of the wave has no support and topples over (breaks)5 The wave washes up the beach as swash and returns as backwash

How do you get bigger waves? - How long the wind has been blowing - Wind speed/strength - The distance the wave has travelled (fetch)

beach

breaker

Surf zone

Crest

wave height increases

wavelength decreases

Deep-water wave

½ wavelength

How are waves formed?

Why do waves break?

Constructive

Destructive

Destructive:

Constructive:

Tides are when the moon has a gravitational pull on the earth and the ocean. They can also be caused by the moon and the sun's pull. High tide happens when the sun and the moon both have a gravitational pull on the earth and sea from one direction. Low tide occurs when the sun and moon are at right angles to each other and when that happens, the sun diminishes the pull of the moon [creating low tides].Video to help:

chemical

mechanical/physical

biological

Weathering is the process by which rocks and materials are broken down in situ [natural material] (does not involve movement) due to biological and weather processes e.g. rain, wind, ice, plant roots. There are three types of weathering:Chemical - Rain is slightly acidic. That's because it dissolves CO₂ (carbon dioxide) from the air. So, it reacts with limestone and dissolves it awayBiological - Roots work their way into cracks in rocks, and widen them. Burrowing animals can also make cracks bigger.Mechanical/Physical = At 0°C, water freezes in cracks. It expands as it freezes, so cracks get wider. This happens again and again until the rock eventually falls apart

Link to help:

Erosion is the process by which rocks, soils and materials are worn down and moved elsewhere due to mechanical and chemical action. There are four different types of erosion:Hydraulic Action - The force of the water hitting the cliffs and compressing air into small cracks causing the rock to weaken and break apartAbrasion - The hurling of rocks at the cliff face; this is like a sandpaper actionAttrition - Rocks hit against each other in the wave to leave smooth, rounded pebblesSolution - Acidic sea water dissolves any minerals in the cliff face