Coasts EQ1 (2B.1) Flashcards
what is the littoral zone ?
a zone that stretches out in to sea and on to the shore and is constantly changing. It is divided in to 5 parts: coast, backshore, foreshore, nearshore, offshore
what factors effect the littoral zone ?
short term- individual waves, daily tides, seasonal storms
long term- sea level and climate change
what are the different processes that effect the coastline ?
natural: - sediment input from sea and rivers -destructive/constructive waves -longshore drift -tidal range human: -dredging -coastal defences -dams
what are the 3 components of the coastal system ?
- inputs- marine(waves, storms), atmospheric, land(geology, tectonic activity), people
- processes- weathering, mass movement, erosion, transport, deposition
- outputs-erosional land forms, depositional land forms
what are the 4 things that can be used to classify a coast ?
geology, wave energy, wave type and sea level rise
what are the 2 main types of coast ?
rocky coasts- rocky cliffs that vary in height. There are 2 types which are steep marine erosion dominated cliffs and curved subaerial process dominated.
coastal plains- low lying flat areas. These tend to be wetlands and marses
what are the 3 types of rock ?
metamorphic, igneous and sedimentary
what are igneous rocks ?
- created by cooled lava or magma
- they have crystals
- e.g basalt and granite
what are sedimentary rocks ?
- small particles that have been eroded and transported in layers
- can be from remains of plants and animals
- e.g limestone and chalk
what are metamorphic rocks ?
- other rocks changing from extreme heat and pressure
- they are very hard and form crystals
- e.g marble which is made from slate
what is diferential erosion ?
small scale areas of weakness and more resistant areas where different land forms could be created
what is coastal morphology ?
the shape and form of coastal landscapes and their features
what is coastal recession ?
another term for coastal erosion
what are the 3 elements to geological structure ?
- strata- different layers of rock
- deformation- tilting and folding by tectonic activity
- faulting- fractures that have moved rocks from their original postions
what is the difference between concordant and discordant coastline ?
concordant- strata parallel to coastline
discordant- strata 90 degrees to coast
what is a cliff profile and what are the different types ?
the height and angle of a cliff face plus its features. They are by the resistance of the rock and the dip of the rock strata
how does coastal vegetation stabilise coastal sediment ?
- the roots binds sediment particles together making them harder to erode
- submerged plants can protect the sediment surface so it isn’t exposed to moving water
- they reduce wind speed due to friction
what is plant succession ?
it is the changing structure of plants over time
how does plant succession occur ?
It starts by pioneer plants which grow in the bare sand or mud. The following stages are called seral stages and the end product is called a coastal climax community. Some examples of a coastal climax are sand dunes and marshes.
how are sand dunes formed ?
embryo dunes are colonised by the pioneers species. these stabilise the sand and add dead organic matter which allows other plant species to grow and create the dune.
how are salt marshes formed ?
he silt and sediment form rivers are deposited at the mouth of the river that is exposed to low tide. The silt and sediment accumulates with plants to form the marsh.
