2.1 - Coastal processes Flashcards
What are the zones that the littoral zone can be divided into
-name them in order
coast
backshore
foreshore
nearshore
offshore
What is the backshore zone found in the littoral zone
-what is it
area between the high tide mark
- affected by wave action during major storms
What is the foreshore zone found in the littoral zone
-what is it
area between high tide and low tide mark
- seen as most important area for marine activity
What is the nearshore zone found in the littoral zone
-what is it
-area of shallow water where friction occurs between seabed and waves- causing waves to break
What is the offshore zone found in the littoral zone
-what is it
area of deeper water beyond the point where waves begin to break
friction occurs between seabed and waves- could cause distortion in wave shape
Name the 2 main types of coastlines formed by the littoral zone
Rocky/ Cliffed coastlines
- Coastal plain landscapes
What are rocky coastlines
reas of high relief
resistant rock areas- resistant to erosive power of sea, wind, rain
high energy environments
rock types: igneous, sedimentary and metamorphic rocks- granite, slate, limestone
erosion is greater than deposition
destructive waves
What is weathering
chemical, bilogical, mechanical breadown of rocks into smaller fragments in situ
What is mass movement
landslides, slumps, rockfalls all of which move material downslope under the influence of gravity
What is surface runoff
water, usually during heavy rain, flowing down cliff face and causing erosion
What is the littoral zone
-boundary between land and sea
Why does the littoral zone vary
due to:
short-term factors- daily tides, seasonal storms, individual waves
long-term factors- changes to sea levels, climate change
Name the 3 coastal landscapes the littoral zone forms
rocky, cliffed coastline
sandy coastline
estuarine coastline
What are sandy coastlines
areas of low relief with sand dunes and beaches, that are much flatter
form in areas with:
less resistant geology
a low energy environment
where deposition > erosion
constructive waves
What are estuarine coastlines
areas of low relief with salt marshes and mudflats (estuaries)
form:
in river mouths
where deposition > erosion
in a low energy environment
usually in areas of less resistant rock
What is coastal accretion
deposition of sediment at the coast and the seaward growth of coastline- creating new land
What is dynamic equilibrium
balanced state of a system when inputs and outputs balance over time
How are coastal plains maintained in a state of dynamic equilibrium in many locations
deposition of sediment from river systems inland and from offshore and longshore sources
erosion by marine action
What is a cliff profile
height and angle of a cliff face as well as its features
Name the inputs in the coastal system
inputs
marine- waves, tides
atmospheric- weather/ climate
land-rock type, structure
people- human activity, coastal management
Breakdown the coastal system
-inputs -> processes -> outputs
Name the processes in the coastal system
weathering
mass movement
erosion
transport
deposition
Name the outputs in the coastal system
erosional landforms
depositional landforms
different types of coasts