Lecture 9 - Coastal Erosion Flashcards
What are some coastal hazards?
- Strong coastal currents
- Coastal erosion
- Sea-level rise
- Storm surges
- Tsunamis
How are waves produced?
Wind blowing over the ocean or a lake transfers some of its energy to the water
The size of a wave depends on which 3 factors?
- Velocity of the wind
- Duration of the wind
- Fetch
Rogue waves?
Waves that don’t become organized into groups when moving away from the source
Wave height?
The distance between the trough and the crest of a wave
Wavelength
The distance between successive wave crests
Wave period
The time in seconds for successive waves to pass a reference point
Wave sets generated by storms far out at sea are called_____
swells
What happens to waves as they approach the coast?
Wavelength and velocity decrease, wave height increases, period remains constant
- Release a large amount of energy as they rush ashore
Eustatic Causes?
The change in the amount of water in the oceans
Isostatic causes?
The local sea level change
What is the dominant control on eustatic sea level?
Climate change
- temperature increases causing glaciers and ice sheets to melt, amount of water in oceans increases
Glacio-isostatic uplift?
Caused by the unloading of glacial ice
Hydro-isostatic uplift?
Caused by unloading of contentental shelves due to eustatic sea-level lowering
What causes the shorline to move landward?
Erosion of sea cliffs and lakeshore bluffs by waves and landslides
