Coastal Systems & Wind Processes Flashcards
1
Q
How do coastal environments place in the geologic time scale?
A
relatively young
2
Q
What interactions form coastal environments (5)?
A
- land
- ocean
- atmosphere
- sun
- moon
3
Q
What are the three zones of a coastal environment?
A
- littoral zone: extends into the water until wave action does not affect sediment on the seafloor
- shoreline: where the sea and land meet
- coast: extends until the first major landform change
4
Q
What is the mean sea level and how does it vary (4)?
A
- based on average tidal levels recorded hourly over many years
- varies around the world based on ocean currents, tides, temp. of air and ocean, air pressure, prevailing winds, gravity, and oceanic volume
- sea levels change through climate change, tectonic activity, and glaciation
- over the past 100 years, sea level has been increasing
5
Q
What are tides (3)?
A
- twice-daily osceillations in sea level
- locations around the world experience different tidal fluctuation
- exist in oceans and very large lakes
6
Q
What causes tides (4)?
A
- tidal bulge: water on Earth is pulled outward by the Sun and Moon
- shift from high tide to low tide caused by Earth’s rotation through the tidal bulge
- spring tide: higher tides occur when Earth and Moon align with the Sun and pull in the same direction
- neap tide: lower tides occur when Earth and Moon are not aligned with the Sun, weakening gravitational force
7
Q
What is tidal range?
A
the difference between consecutive high and low tides
8
Q
What are waves and how do they vary in scale (2)?
A
- form as a result of friction between wind and ocean surface
- can be large and powerful or small and weak
9
Q
What are swells (3)?
A
- regular patterns of smooth, rounded waves that exist in the open ocean
- swells compress and become top-heavy as they move closer to the coast
- breaker waves form when the swell becomes too top-heavy and collapses over itself
10
Q
What are tsunamis (4)?
A
- form in the aftermath of an earthquake, landslide, or volcanic eruption below the ocean’s surface
- movement displaces a huge amount of water, creating large waves
- travel at a very fast rate
- have a large wavelength but a low height
11
Q
What are erosional coastlines (5)?
A
- more erosion occurring
- aka “emergent coastlines”
- found along Pacific coast of U.S.
- more common in areas with tectonic activity
- waves act to erode away material and straighten coastline
12
Q
What are seven features of erosional coastlines?
A
- headlands: protruding landforms of erosion-resistant rock
- refracted wave fronts: waves hit furthest point of headland and bend to attack the sides of that point, resulting in…
- sea caves
- sea arches
- sea stacks
- sea cliffs
- wave-cut platforms
13
Q
What are depositional coastlines (3)?
A
- more deposition occurring
- aka “submergent coastlines”
- found along Gulf Coast and Atlantic Coast of U.S.
14
Q
What are three features of depositional coastlines?
A
- barrier spit: sandbar which extends parallel along shoreline in same direction as longshore drift; does not extend entirely along bay
- lagoon: small body of water formed when the bay has been completely cut off by the barrier spit
- tombolo: barrier spit which extends perpendicular to shoreline, connecting an off-shore island
15
Q
What determines the material which makes up beaches?
A
the type of rock which makes up the coastline
