Coasts Flashcards
Constructive Waves
Stronger swash
Weaker backwash
Long wavelength
Shallow gradient
Low frequency
Destructive Waves
Stronger backwash
Weaker swash
Short wavelength
Steep gradient
High frequency
Hydraulic Action
Water and air going into cracks and breaking up the rock (cliff)
Abrasion
Waves hurling rocks at cliffs which break rock down
Attrition
Rocks hitting each other and breaking each other down
Corrosion (solution)
The dissolving of rocks by acids in seawater
Weathering
The breakdown of a material in situ (no movement)
Mechanical Weathering
Physical breakdown by environmental factors
Examples: Freeze-thaw weathering, onion skin weathering / exfoliation weathering
Biological Weathering
Involves living organisms
Examples: Acids in plant roots dissolving rock, plant roots breaking up rock through cracks
Chemical Weathering
Acids in rainwater can dissolve rocks
Rockfall
Rocks falling of cliff, typically due to freeze-thaw weathering
Mudflow
Saturated soil flows down a slope
Rotational Slip
Saturated soil slumps down a curved surface
What are four factors that influence the coastline?
Vegetation
Geology
Sea level
Humans
Submergent Coastline
Coastline that has been flooded due to rise of sea level
Forms features such as Fjords and Rias
Emergent Coastline
Coastlines where sea levels have fallen
Forms features such as raised beaches and relict cliffs
Eustatic Change
Change in sea level due to volume of water changing
Isostatic Rebound
Rise of land masses that used to be under ice sheets during previous ice age
Goods
Tangible outputs with physical dimensions
Services
Intangible process that cannot be weighed
Describe the distribution of coral reefs and mangroves
In a narrow band around 30 degrees north or south of the equator in the tropics
Storm Surges
Sudden rises in sea level caused by strong winds and low air pressure
Tsunami
A huge displacement of water due to earthquakes or volcanic eruptions
Reclaimed Land
Land that has been gained from the sea due to management or sea level fall