Term
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Definition
| When rising sea levels drown old river valleys. |
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Term
| What is the transport path of sand on a beach? |
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Definition
| Beach drift causes sand to move in a zig-zag pattern because waves reach the shoreline at an angle. |
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Term
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Definition
| Flat accumulation of sediment on beach high above tideline. (less wave energy) |
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Term
| Beach profile: Beach scarp |
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Definition
| A vertical face cut by a wave and marks high tide. |
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Term
| Beach profile: longshore trough |
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Definition
| Below the low tide mark, scoured by currents. (more wave energy) |
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Term
| Beach profile: longshore bar |
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Definition
| submarine sand ridge, parallels shore, made from sand removed from the beach. |
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Term
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Definition
-lower energy
- sand moves onto beach
- wide and steeper with scarps |
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Term
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Definition
- higher energy
- more storms
- more erosion
-sand removed from beach to bars
- narrow and flatter |
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Term
| What is a longshore drift? |
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Definition
Produced by oblique waves
moves sand along the beach parallel to the coast |
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Term
What are ripcurrents?
How can they be recognized? |
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Definition
In strong winds, water piles up on beach and returns to the sea in a focused current that cuts through the surf zone‘rips through sand bar and surf’
Recognized:
- usually before or after a storm
- when waves are coming straight in
- depression on the beach
- smaller incoming waves(flatter)
- murky, sediment laden water |
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Term
| What are groins, jetties, breakwaters, seawalls? What effect do they have? |
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Definition
They are hard structures to stop the erosion process.
If perpendicular to beach( groins and jetties): traps sand with longshore drift
If parallel to beach: minimizes wave energy and erosion |
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Term
| What is beach replenishment? |
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Definition
| A soft structre devised to stop the erosion process. Placing sand on erosion. Its a temporary solution. |
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Term
| What effects do storms have on coastal features? |
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Definition
-erosion AND deposition
-island elimination
-alter tidal circulation patters |
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Term
| How do we pay for coastal development and maintenance? |
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Definition
National Flood Insurance Program (NFIP) managed by FEMA, since 1968
Provides insurance for properties considered too risky for private insurers
Collects $2 billion/yr in premiums
Will pay out $30 billion for Katrina alone
Must borrow the rest…from taxpayers
Multiple claimants pay 2% but collect 25% |
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Term
| Depositional Coast: Sand spit |
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Definition
| Where the beach stretches out into open water- recurred spit often depict longshore current. |
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Term
| Depositional Coast: deltas |
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Definition
| massive accumluations of sediment transported to river mouth and deposited where river currents slow. Builds outward over time. |
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Term
| Depositional Coast: How are Barrier coasts formed? |
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Definition
| when coastal dunes were submerged during sea level rise. |
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Term
| Longshore drift is going in the direction of..... |
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Definition
| the side that has the most deposits of sand. |
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Term
| How is a sea arch formed? |
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Definition
| 1) cave formed by wave action, then 2) cave breaks through to make an arch. A sea arch is a landform produced by coastal erosion of a prominent headland. Sea arches form when sea caves are excavated so deeply by crashing waves that two caves eroding on opposite sides of the headland |
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Term
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Definition
flooded valleys cut by glacier
Ex: Scandinavia, New Zealand, Northern Canada |
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Term
| Erosional Coast: Volcanic Coast |
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Definition
fresh rock added to coastline
Ex: Hawaii |
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Term
| Erosional Coast: Faulted Coasts |
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Definition
regions where faults habe divided, upliftef or down dropped coast
(California) |
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Term
| Erosional Coast: Coral Atolls/uplifted reefs |
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Definition
| limited sediment availability. New ‘rock’ added via coral growth |
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Term
| Erosional Coast: Emerging coasts |
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Definition
| Terraces each represents an old wave cut surface, land uplifted |
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