Flashcards in Marine Processes Deck (10)
Name and give a brief definition of 6 types of erosion
1) corrasion - rock sediment within waves hitting and wearing down rock
2) hydraulic action - cracks with air in are pressured when waves compress the air
3) cavitation - receding waves allowing air to expand
4) wave quarrying - energy of wave breaking the rocks
5) solution - soluable rocks being dissolved
6) attrition- rocks within water break ewch other up
Give five factors effecting erosion rate
Waves - destructive or constructive?
Fetch - long or short?
Beach formation - beaches absorb wave energy
Human activity - management strategies
Geology - chemical make up of the rock
Lithology - physical structure
What are the transport processes in the costal system?
Solution - soluble material carried
Saltation - heavy particles bounce along
Suspension - small particles carried within the water
Traction - large boulders
Describe the process of long shore drift
Waves approach a beach at an angle due to the pervailing wind, but backwash occurs perpendicular to the coast. Hence there is a zigzagging pattern
What are the two types of deposition?
When will depositional occur?
Marine - by the sea
Aeolian - by wind
Occurs where sediment load exceeds the ability of water to carry it
With an example of each give the three types of weathering
Chemical - carbonic acid from CO2 will dissolve limstone (CaCO3)
Biological - nesting birds
Physical - freeze thaw, water expands by 10% when it freezes + wetting and drying ( clay gets cracks when it dries out)
Give six types of mass movement
1) rockfall - arches + stacks collapse rapidly
2) landslides - softer material slumps triggered by torrential rain
3) mudflow- movement of fine soils, after heavy rain
4) slumping - large sections of unconsolidated ground situated over resistant rocks
5) soil creep - gradual movement of soil forming terracettes
6) run off, overland flow picking up fine sediment
What factors increase the chance of mass movement?
Heavy rain - lubrication
Saturated ground - heavier
Increased weathering or marine erosion
What two types of coastline cause the formation of headlands and bays describe how they are formed at each
Concordant = striations are parallel. Waves exploit a crack in more resistant rock which forms a channel into less resistant rock which is rapidly eroded.
Discordant = striations are perpendicular. Less resistant rock is eroded faster