Coasts - Theme 2 - GEOMORPHOLOGICAL Flashcards
What is geomorphology
-study of landforms and their processes
What is a marine process
-opperates upon a coast line and are connected to the sea such as waves, tides and longshore drift
What is a sub ariel process
- Processes that mainly effect land - mass movement and weathering
- Includes processes that slowly break down the coastline
What are the three main categorys of weathing
- Mechanical/Physical
- Biological
- Chemical
What is frost shattering
- PHYSICAL
- Porus rock lets in water
- freezes
- expands
- add pressure
- splits
- NEED A TEMP RANGE OF +-0
What is salt crystallisation
- PHYSICAL
- Porus rock
- Salt water enters
- water eveporates
- leaves salt crystals
- build pressue
- cause to break
What is wetting and drying
- Frequant drying of wetting and drying
- Leads to rock rich in clay (shale) to expand when wet and contract when dry
- crack and break up
- more vunurable to freeze thaw
What is Plant weathering
- BIOLOGICAL
- Thin roots grow into rocks and crack
What is plant water weathing
- water runs through vegatation and becomes acidic
- chemical weathing in reslut of BIOLOGICAL
What is bird and animal weathering
- BIOLOGICAL
- Birds (piddock) dig into foround for food and annimals burrow
- leaves holes for vunurability
What is marine organism weathering
- BIOLOGICAL
- Limpits and algee can chemically erode by producting acids
What is carbonation
- CHEMICAL
- rain falls and reactis with the CO2 in the air
- this creates CARBONIC acid
- this errodes CALCIUM CARBONATES - CaCO3
- These are rocks like chalk and limestone
What is oxidation
- CHEMICAL
- FERROUS (iron) rocks react with oxygen
- brown yellow stain
- VUNURABLE
What is solution and acid rain
- CHEMICAL
- Removal of rocks by rain acidic water
- the acid rain comes from gases in the atmosphere - nitric acid and weak sulfuric acid - reacts with minerals to make them weaker
What is hydrolysis
-Mildy acid water combines with water to create claus and dissolvelble salts - these break down rocks
What is mass movement
-movement of sediment in a sub ariel processes
What is soil creep
- extremly slow
- soil gets wet - when wet soil particales sink
- soil drys and move to the surface
- the surface’s incline means the soil particle rolls down the hill by mms
- this is repeated
- similar to longshore drift
What are the charictoristics of soil creep
-little rows of soil that are parrel to cliff face
What is mudflow
- Clay sits below unconsilidated or weak rock
- water gets trapped withing the rock
- this inceases pore pressure (pressure of ground water in rock pores)
- this forces rock particles apart
- leads to the slope to fall
- leads to unconsilidated sediment to fall
- needs heavy rain to make mud
what is a landslide
- Block of rock moves rapidly
- caused by rainfall or earthquake
- rock moves down and brings sediment
What is a rockfall
- Sudden collapse of induvidual rock fragments
- steep cliffs
- mechanical weathering or erosion
- fasll to the shore line
- input to sediment cell
- SEDIMENT CALLED SCREE
What is a rotational slump
- curved side plane of impermiable rock
- other layers of rock sit ontop of this
- when there is consistant high tides it can cause excessive lubrication
- this can cause slumping due to gravity
- IT PRODUCES A CURVED SLIDE PLANE
Label a rotational slump
- the top is called a head
- the vertical parts are called SCARPS
- the bottom is called a foot
- the very bottom is called a toe
- there is a curved slide plane
What is runoff
-water that leaves a drainage basin
