coastlines Flashcards
Draw and label a typical beach profile
Lol, didn’t pay so no photo. look at notes
breaker zone
marks the transition from deep water to shallow water
surf zone
Part of the breaker zone where waves are actively breaking
swash zone
Waves run up and down this zone.
foreshore
located between the low and high tide mark
Backshore
land after the high tide mark
How do tides work?
Gravitational forces from the sun and moon change the tide of the water
What is a storm surge?
- Rise in water level caused by high wind and low atmospheric pressure
- lower atmospheric pressure means less pressure on the water level, meaning that it has less resistance to rise.
- The wind direction and force can push water and pile it up when it hits the coastline.
What are the different types of sea level changes, and list some examples.
Eustatic
- global sea level changing
-examples: melting glaciers, a tectonic process that changes the shape of the seafloor (oceanic-oceanic)
Isostatic
- local sea level changes
- examples: loading or unloading of crust/ convergent plate boundaries at the coastline (oceanic-continental).
What are the two types of waves? and explain each one
Wind-generated waves
- travels downwind
- amplitude is determined by wind speed, duration, and fetch (uninterrupted distance over water that the wind blows in a consistent direction)
Displacement waves (tsunamis)
-generated by mechanical movements such as landslides, earthquakes, and volcanic eruptions.
What are breakers and how do they differ with different types of shore?
steep shore
- quick energy lost
- plunging breaker (dramatic and powerful)
gentle shore
- energy lost gradually over a large area
- spilling breaker
What is refraction in relation to waves approaching the shore?
The wave bends towards the shore.
What are longshore currents?
-They go in the direction in which the wave is carrying the sediments.
-Parallel to the coastline.
What are five erosion features, and give a quick explanation
Wave-cut cliffs
- Steep coastal cliffs formed by the relentless erosion of waves pounding against the rock
Wave-cut platforms
- Flat, rocky platforms at the base of cliffs, shaped by wave erosion and often exposed at low tide
Sea stacks
- Isolated pillars of rock rising from the sea, resulting from the erosion and isolation of headlands or cliffs.
Sea arches
-Natural rock arches or bridges formed by the erosion of a headland, leaving an opening through the rock.
Sea caves
- Hollow openings in coastal cliffs or rocks created by wave action and erosion, typically accessible by water.
What are five depositional features, and give a quick explanation.
All are formed by longshore drift sediment deposition.
Splits
-deposition of sediments that extend from the mainland into a body of water
Tombolos
- deposition of sediments that connects an island with the mainland or another island
Barrier island
-deposition of sediments in the sea parallel but not connected to the shoreline.
Tidal inlets
-narrow pathways of water that connect closed bodies of water with the ocean.
Longshore bars
-underwater or partially submerged ridges of sand or sediment running parallel to the shoreline
