coastal processes

physical weathering

• Freeze-thaw
• pressure release- overlying rocks removed by weathering and erosion, underlying rocks expands and fractures
• thermal expansion- heated up= expand, cool down= contract, rocks eventually crack and break off
• salt crystallisation-salt seeps into pores in rocks, crystals grow which puts pressure on rock and it cracks

chemical weathering

• oxidation- erosion by air as oxygen reacts with original rock composition
• carbonation- carbonic acid, mineral dissolves in water
• hydrolysis- chemical reaction between rock and minerals
• hydration- water molecules added to rock minerals create new materials

biological weathering

• tree roots- encourages animal burrows
• organic acids- plants acids erode rocks, produced in decomposition in soil which increases acidity and reacts with minerals

mass movement

• Transfers rocks and regolith onto shore below
• rockfall- if cliff is on 40 degree or more angle or bare face, rocks become detached
• slides- linear: will fall straight down, angled: will slump, common in weak rocks like clay when heavy or wet

erosional processes

• solution- minerals (magnesium carbonate) dissolves from coastal rocks, limited effect on seam unless water is polluted or acidic
• pounding- mass of breaking waves exerts pressure on rocks causing it to weaken and fracture
• hydraulic action- waves break against cliff edge , air and water trapped in crevices compresses, waves reduce, pressure drops, air and water suddenly expand and crack widens
• abrasion- waves armed with rock particles scour the coastline rubbing against rocks
• attrition- rock particles transported by wave action collide with coastal rocks and become worn, they are smooth, well rounded, smaller and eventually produce sand.

tranportational processes

• solution- minerals dissolved in the water, its invisible an only seen when water evaporates
• suspension- small particles like sand, silt and clay transported by currents, muddy appearance larger particles can be carried this way during storms
• traction- largest particles are rolled along the sea floor by force of the flow
• saltation- irregular movements of material that is too heavy to be carried in suspension, bounce and drag along surface