Coasts: Gateway 1

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Coasts: Gateway 1 by Mind Map: Coasts: Gateway 1

1. Factors Affecting Coastal Environments

1.1. Waves

1.1.1. - main shaping force of coastal environment - transfer of energy from moving air to water surface

1.2. Tides

1.2.1. - gravitational pull of moon and sun - affect processes eg. coastal erosion, sediment transportation & deposition

1.3. Currents

1.3.1. - distributes sediments & regulating temperatures - shape coasts through coastal erosion, sediment transportation & deposition

1.4. Geology

1.4.1. - arrangement & composition of rock - determines resistance to erosion

1.5. Types of Ecosystems

1.5.1. - mangroves, coral reefs = reduce impacts of waves on shore

1.6. Human Activities

1.6.1. - eg. living, trading, fishing, engaging in recreational activities, pollution

2. Wave Motion

2.1. Near the Coastline

2.1.1. - water is shallow & interacts w. seabed

2.2. Nearer the Coastline

2.2.1. - waves move into shallower waters - base slows down (FRICTION) - wave height increases, wave length decreases

2.3. Nearest the Coastline

2.3.1. - base of wave stops - wave crest becomes steeper, topples over - waves break on coast, releases energy

3. Waves & Coastal Areas

3.1. Waves on the Beach

3.1.1. Swash

3.1.1.1. - water that rushes up beach - carries sediments

3.1.2. Backwash

3.1.2.1. - swash that has lost energy (GRAVITY & FRICTION) - carries sediments from shore into sea

3.2. Types of Waves

3.2.1. Constructive Waves

3.2.1.1. - small, low waves - low wave height, long wave length - wave frequency: 6-8/min - strong swash, weak backwash - gentle coastal slope, sheltered coast

3.2.2. Destructive Waves

3.2.2.1. - large, high waves - high wave height, short wave length - wave frequency: 10-14/min - weak swash, strong backwash - steep coastal slope, open coast

3.3. Wave Refraction

3.3.1. - change in wave direction - converge on headland = increased wave height & erosive energy - diverge in bays = decreased wave height & erosive energy

4. Coastal Processes

4.1. Coastal Erosion

4.1.1. Hydraulic

4.1.1.1. - trapping of air in rock joints - weakening of joints

4.1.2. Abrasion

4.1.2.1. - knocking & scraping of sediments on coast - undercutting

4.1.3. Attrition

4.1.3.1. - rubbing & hitting of rock particles - smoothening process

4.1.4. Solution

4.1.4.1. - chemical reaction of sea water and minerals - weakening & disintegration

4.2. Sediment Transportation

4.2.1. when waves approach coast at angle... - swash at angle, ackwash horizontal (BEACH DRIFT) - LONGSHORE CURRENTS in nearshore - combined effect = LONGSHORE DRIFT

4.3. Sediment Deposition

4.3.1. - large sediments deposited first