Coasts Revision

Coast - narrow contact zone between land + sea

Important - 

• tourism                         
• trade
• coastal habitats
• tidal/wave energy
• water sports
• transport
• defense
• employment

Dangerous-

• wind/water erosion
• acid rain
• sea level rise
• low-lying areas

Conflict-

• space
• reefs
• beaches-best sand etc.
• attractiveness
• population
• businesses
• noise pollution

• unique, valuable, often threatened areas
• coastline - ever chaniging boundary zone between land + marine/sea environment

Fetch - distance waves travel across body of water before hitting coastline.

• controlled by size of ocean
• power of waves influenced by power of wind pushing waves
• strong wind, long fetch - more likely to produce destructive waves

• wind blowing over sea creates friction
• waves formed due to circular motion formed
• base of wave moves slower than top of wave

Destructive waves

• waves tall relative to length
• waves frequent - between 10 & 14 breaking into shore every min
• waves create steep beach angle
• often produce pebbly beaches
• tail breaker - wave breaks down onto beach
• weak swash, strong backwash
• formed by bad storms

Constructive Waves

• waves flat relative to length
• waves less frequent - between 6 & 8breaking into shore every min
• waves create gradual  beach angle
• often produce sandy beaches
• strong swash, weak backwash
• formed in middle of ocean 

Swash - forward movement of wave up beach   Backwash - backward movement down beach & wave broken

Longshore drift - process which waves move material along coast.

• in 1 direction only - of prevailling wind
• e.g. Britain - from SW

• backwash always at right angle to beach

Erosion

Weathering - breakup or decay of rocks in oringinal place or close to earth's surface

Erosion - wearing away of land's surface. Inc. breakdown of rock & its removal by wind, water or ice

Land based processes - subaerial erosion

Sea based processes - marine erosion