8- Coastal Processes Flashcards
3 inputs into a coastal system
Geothermal
Solar
Gravitational
3 coastal processes
Erosion
Transportation
Deposition
Are coastal systems open or closed
Open as inputs and outputs move out of boundaries (energy and material)
Which rock type has fastest erosion rate?
Sedimentary due to clastic lithology
Which rocks are impermeable?
Most igneous and metamorphic
And mudstone
Which rocks are permeable?
Sedimentary rocks (limestone, sandstone)
2 ways permeable rock cliffs can cause cliff to be weak
Water emerging from underground at spring causes surface tun off erosion
Groundwater flow through rock layers removes cement holding rocks together
How does vegetation stabilise sediment?
- they all encourage deposition
Roots bind sediment together
No wind erosion- reduces wind speed and friction with plants
Growing plants in sediment provides PROTECTIVE LAYER- surface of sediment not directly exposed to water
Role of embryo pioneer plants
Stabilise mobile plants with root systems
Reduce wind speeds
Add dead matter to sand to begin soil formation
What are fixed dunes?
Dunes that are almost totally covered by vegetation
Main role of embryo pioneer plants
Alter environmental conditions so other plants can tolerate and grow
What are dune slacks and how are the caused?
Eroded dunes
Caused by wind erosion- blow out of sand stops when erosion hits damp sand at water table
Why is marram grass important to formation of sand dunes?
Stabilises blow sand- tough leaves that can cope when sand blasted
3 metre long roots- traps water below dunes
Can survive in 60 degree temperatures
