coasts final exam Flashcards
What drives ocean currents?
temperature and salt distribution in water
What affects temperatures?
Solar Energy, and Atmosphere
current effected by the wind that has gyres
surface currents
What is the Coriolis Effect?
The effect that has to deal with earth’s rotation effect the deflection of objects not attached to earth’s ground
How the Coriolis Effect has an impact on the currents in the ocean?
The currents in the nothern hemisphere go to the right, or clockwise, while the currents in the southern hemisphere go to the left or counterclockwise
What is thermohaline circulation?
When cold water sinks and warm water rises - cold water travels in deep currents
What produces the structure of the waves at the surface?
The wind
How do waves get their “shape”?
The wave base interacts with friction and begins to tip over these are known as break waves
The bending of waves due to wave interaction; sea floor interacting and changing direction by slowing down; can affect how the coast line looks
refraction
What is a long shore current? How does it affect the shore?
the movement of sediment along the coast; affects how sand is moved based on how the waves approach the shoreline; waves come at zig zag angle
winds blowing on shore due to high pressure wind and low pressure water ; surface waters drawn downward
downwelling
wind blowing off shore due to low pressure wind and water filling the empty gap; deep waters pushed upward
upwelling
What causes tides?
Gravitational effect by attraction of the earth to the sun and moon
What is a spring tide? what kind of tides are produced
Alignment of the earth, Moon, and Sun - high tides
What is a Neap tide? what kind of tides are produced
a 90 degree angle between the earth, sun and moon - extra low tides
How does sand migrate as a result of the longshore current?
The waves come in at a zig zag angle, and in result moving sediment up the beach and recessing back into the ocean taking some sand with it
What is a rocky beach?
area where not a lot of sand occurs but lots of wave actions occurs. They are steep and narrow with lack of sediment
What are muddy beaches?
low wave action areas where mud gets transported to lower energy environments
What determines the geology of the different beaches?
The sediment and rocks fed into the beach by the waves
What are barrier islands? describe the composition and characteristics
Area where the ocean is separated by a large sandbar thousands of miles long that are changed constantly. they area created due to build up of sediment interaction
what is a spit?
Extension of beach into a bay; these will break off and form barrier islands; forms from longshore drift.
what are tidal flats?
Common in barrier islands; area where there is little water involved next to a shore. Can have water at some point and other it will not; tidal pools can form
What are rocky coasts?
no beach with narrow rocky bluffs and cliffs; lots of wave action
former valleys flooded by marine waters; typical southern river; affected by sea level rising and taking over
Estuaries
U shaped valleys filled with sea water due to glacial development; flooded as sea levels rose; common along rocky coastlines in polar and subpolar regions
Fjords
gentle slopes, low wave action, and extended vegetation; plant directly in the water
wetland coasts
calcite rich structures with skins of living organisms; sensitive to carbon dioxide; in tropical waters and break up waves
reefs
what is the role of plate tectonics and coastlines?
can have active margin shorelines where the rocky coasts are uplifted due to subduction zones; or passive margin shorelines that form due to continental and oceanic crust colliding and developing flat areas
what are the structural approaches to control for beach erosion?
build groins, jetties, or sea walls, OR provide beach nourishment
Wall sticking out perpendicular to the beach,interupts water flow and sediment distribution
groin
constructed in pairs to control sand deposition, wave erosion, and protect shorelines
jetties
concrete structure meant to stabilize and control erosion effects of waves
sea wall
How do humans go about pumping sand back into the water?
Pump sand from off shore on shore, but is bad because it can be washed away
How do storms affect shorelines?
Storms can destroy barrier islands and cause massive erosion and destruction of sediment and shape
