Physical Landscape Flashcards
What are concordant and discordant coastlines and how are coves formed
Discordant -mulitple types rock strata runs perpendicular to sea which can create headlands and bays due to the less resistant rocks eroding faster
Condordant- rock strata runs parralel to coast , alternating bands of hard and soft rock forming differnt landforms
Coves are formed through hard outer layer of rock eroding exposing the softer rock on the inside ,less resistant rock erodes faster than rock on outside and erosion continues to widen the cove ,waves diffract as they pass though opening
What are joints and faults
Joints-small vertical cracks found in all nearby rocks
Faults -larger cracks where the rock has moved
All erosional processes
Corrassian-sand and pebbles are picked up by waves and hurled at cliff face at high tide
Abrasion- sediment scrapes and scours away the cliff face
Attrition-rocks and pebbles hit against each other ,has little effect on coastal erosion
Hydrolic action -wave crashed into cliff face and air is forced into cracks ,high pressure causes cracks to force apart
Soltuion-mildly acidic seawater causing alkaline stones (limewater) to be eroded
All eriosional landforms
Caves,arches,stacks,stumps
Marine erosion causes cracks in cliff face to deepen,creating a cave ,cave depends though marine and Subariel processes
Eventually forming and arch ,arch continues to widen UNTILL falls due to own weight though mass movement
Properties of destructive and contructive waves and what does waves depend upon
Constructive-strong swash ,weak backwash ,low wave height,low frequency,builds beaches ,beaches tend to be sandy beaches
Destructive-strong backwash, weak swash,high wave height ,high frequency,destroys beaches ,beaches tent to be rocky headlands
Strength of wind
How long wind blows
Water depth
Distance of fetch
Longshore drift process
And other ways of transportation
Waves hit at angle due to prevailing winds
Waves push sediment in direction up beach through swash
Gravity pulling sediment back down beach though backwash
The moves along beach overtime
Solution-chemicals disolve in water
Traction-large rocks roll along seabed
Saltation-pebbles and small rocks bounce along seabed
Suspension-tiny rocks float along the water
What is deposition and How do bars and spits form
Deposition-waves loose energy,sediment becomes too heavy to carry
Spit-waves loose energy overtime creating a spit,periodically longshore drift changes direction causing a hook to appear ,spit can turn into slag marsh
Bar-is a spit that has grown across the mouth of the bay,creating a lagoon with still water and overtime this becoming a saltwater lake
Differnt types of mass movement and what type of movement depends upon
Rock falls-occurs on sloped cliffs when rock becomes exposed to mechanical weathering
Landslides-water between layers of rock,rock face reduced friction and allows large chunks of rock to slide off
Mudflow-waterlogged soil flows down face of hill ,bulging at the bottom in a lobe
Rotational slip-soil and rocks becomes saturated and slips creating stepped heads down cliff face
Angle of slope or cliff
Rock type
Previous saturation of ground
Human activities on coast
Housing-coasts are popular due to natural beauty and slower pace of life demand for coastal housing means quiet town will sprawl
Buisness-brings regular income to residents however brings environmental damage
Agriculture-price of land rises,farmers increase profits ,adds pressure to land
Risks to coastlines
Storm surges Bring flooding
Global warming means sea levels rise due to thermal expansion
Global warming increasing more extreme storms
Coastal erosion increases as sea levels rise
Types of defences soft engineering
Dune stabilisation- roots help bind to dunes,protecting land behind
Pros-cost effective,creates important wildlife habitat,minimum impact on wildlife
Cons-planting is time consuming,can easily be damaged
Beach nourishment-sand is added to beach lost through erosion
Pros-maintains beach,tourist attraction,blends in with rest of beach,Large amounts of sand needed on regular basis
Hard engineering
Rip rap-large rocks that reduce wave energy
Pros-cost effective
Cons-the rocks don’t fit with the geology,pose a hazard if climbed upon
Sea walls-concrete structures that absorb and reflect wave energy
Pros-effective Erosion protection
Cons-visually unappealing,expensive to contract and maintain
