Coasts Eq1 Flashcards
(87 cards)
What is a high energy environment
Destructive waves breaking on shingle beaches
What is a Low energy environments
Constructive waves breaking upon sandy beaches
What is a Protected environment
Where wave action is limited in small shelter (eg a split)
Characteristics of high energy coasts
Waves.
Processes.
Landforms.
General location.
Waves-more powerful (destructive) waves, calmer conditions
Processes-sediments from eroded land, mass movement and weathering, supplied by offshore currents.
Landforms-cliffs, wave cut platforms, arches, sea caves, stacks
General location- exposed to largest waves, highland and lowland coats, rocky landscape.
Characteristics of low energy coasts
Waves.
Processes.
Landforms.
General location.
Waves- less powerful (constructive) waves, storm conditions
Processes- sediments from rivers, longshore drift and near shore currents
Landforms- beaches, spots, bars, sand dunes, mudflats and salt marshes
General location- sheltered from large waves, can cause vegetation to grow and sand dunes
High energy coasts summarised
Where the rate of erosion exceeds the rate of deposition
Low energy coasts summarised
Where the rate of deposition exceeds the rate of erosion
Terrestrial factors affecting coasts
The type of rock (eg the soft rock will erode quicker, hard rock slower)
Tectonics in the area (earthquakes can move rock or trigger tsunamis)
Human factors affecting coasts
Global warming is altering the shape of the coastlines due to the rising sea levels
Humans can settle on coastlines and will rise to the proximity of the sea
atmospheric factors affecting coasts
Climate change
Temperature alter the shape of the coast
Marine factors affecting the coasts
Waves, tides and salt spray play in altering the shape of coasts
Corals can alter the shape of the coasts
Primary coasts facts
Develops from non marine processes
Only gets altered since the last raise in sea level
Partially drowned by the post glacial rise of sea level
Secondary coasts facts
Shape primarily by Marine Action
May or may not be primary before
what is macro-scale
concordant and discordant
what is meso scale
folds,faults and dips
what is a micro scale
bedding planes, joints, pores
3 factors affecting rock resistance
-hardness
-structure~ affecting how water and wind interacts with the surface
-PH~ affects erosion resistance by influencing mineral stability + chemical reactions
what is a permeable rock
it allows water to pass through them and cracks and joints enlarge
what is a impermeable rock
it does not allow groundwater flow and allows greater amounts of surface runoff, this has its own erosive force on the face of a cliff
examples of igneous rock (interlocking crystals make it v strong)
extrusive-basalt, andesite and obsidian
intrusive- granite diorite and gabbro
examples of sedimentary rock (resistant to erosion less strong)
clastic rocks-bits of rock cemented together (sandstone, shale and mudstone)
organic rocks- chalk and coal
chemical rocks-limestone, gypsum and rock salt
examples of metamorphic rock (clastic-loose parts erodes very quickly)
gneiss, schist, quartzite, slate and marble
what is strata
its layers of rock
what are bedding planes
natural breaks in the strata (horizontal cracks)