Geomophic Processes / Landscape Flashcards
Geomorphic
Relating to the form of landscape and other natural features
Three areas that have important impacts on Geomorphic processes
- climate
- geology
- human activity
What is weathering?
The breaking down of rocks in situ (in one place)
this affects the surrounding area which in turn affects the process.
Mechanical (Physical) weathering
Freeze thaw weathering (Frost shattering)
- prominent in the UK
Exfoliation (onion skin weathering)
- from the heat so found more in desert areas.
Chemical weathering
Geology will affect it as some rocks are more susceptible and will be affected more.
Acid rain is often a cause for chemical weathering.
Biological weathering
This is, perhaps, less significant. Plant roots grow in rocks and break them up. Sometime burrowing animals can have an affect.
Solution/Corrosion
Acid water eroding coastlines
Hydraulic Action
Water forces into crack, gets pushed in, crack expands etc.
Can happen if air is forced in too.
Attrition
More for the sediment and load as they hit each other and this makes the peddles smooth.
Corrasion/Abrasion
Load and sediment in the water erodes the bed like sand paper.
Glacial erosion
Abrasion
Plucking (freeze thaw weathing weakens the rock then the glacier plucks it away.
Solution (Transportation)
Minerals are dissolved in the water and carried along.
Suspension
Fine material carried along in the water.
Saltation
Small pebbles and stones bounce along the river bed.
Traction
Large boulders and rocks are rolled along the river bed.
Constructive waves
Strong swash and weak backwash.
Low frequency.
Wave energy dissipates over a wide area.
Destructive waves
Big, strong waves when the wind is powerful and has been blowing for a long time.
Energy is high and the wave has travelled over a long fetch.
Stronger backwash than swash.
Longshore drift
Due to the wind the waves come in sideways, then go out straight. This causes the beach material to be pushed up the beach.
Demonstration of transportation. But leaves the coastal areas open to erosion.
Supraglacial
Glacial transportation on top of the glacier.
Englacial
Transportation inside the glacier.
Subglacial
Transportation under the glacier.
Deposition
Material that was being transported is dropped.
Headlands and Bays
Formed based on rock types.
Hard rock is not eroded as easily as soft rock, which means they stick out into the sea causing cliff, whereas, soft rock is eroded faster and forms bays.
Glacial landforms
Tend to form together.
Corries, Aretes and Pyramidal peaks.
Glaciers form and carve out the side (corries) leaving a jaged sticking up summit with little material around it (pyramidal peak).
Arete = sharp mountian ridge.
Meanders
Happens in a lateral erosion period, with both erosion and deposition.
Rivers try to take the fastest route but if they hit an obstacle like hard rock, they will start to bend around it.
The outside bend will have the fastest flow so erode and the inside bend will be slower, leading to deposition.
Jurassic Coast, Dorset examples
Old harrys rock
- Headland of chalk
- Cave - arch (less vulnerable to erosion but more vulnerable to weathering)
- stack (old harry - vulnerable to sea on all sides)
- stump (old harrys wife)
Lulworth cove
- Coastal and fluvial erosion
Durdle door
Chesil beach
- Tombolo
- Constructive waves
- Deposited by size = sediment sorting process
River Derwent, Cumbria examples
Meanders at cockermouth
Taylor gill force - Waterfall - Hard rock over soft rock - Erodes soft rock rapidly = overhang and plunge pool = overhang eventually drops off + causes more erosion
Floodplains, Workington
- Usually fertile + flat
