Chapter 15 Flashcards
What is a gyre
Circular surface current
What causes surface currents
Wind
Which way do gyres rotate
Circular
How many currents exist within each gyre
Four
How many gyres are there And where
Five north Pacific South Pacific North Atlantic South Atlantic Indian Ocean
What is the Sargasso Sea
Place inside the Atlantic gyre
How long does it take for each current to cycle
Six years
Where is the Gulfstream
Along the east coast of the US
How do currents transfer heat and where is the heat coming from
Convection currents
Equator
How does the current affect nearby land
Moving away from the equator makes it warmer
Moving away from the poles makes it colder
How do currents affect Earth’s heat budget
Try to make ocean temperature equilibrium Warmwater north Coldwater away from poles
What is upwelling
When pushes water away from the coast leaving a void to be filled with cold nutrient rich water from below
How does upwelling Occur
Wind blows water away from the coast
What kind of movement is upwelling and what causes it
Vertical Movement
Wind blowing surface water away from the coast leaving a void to be filled with cold nutrient rich water
Why is upwelling significant to organisms
Cold Nutrient rich water = Happy plankton = Happy fish
What is another name for the global ocean conveyor belt
Thermohaline circulation
What does thermohaline circulation accomplish
Equals out world salt water because of density differences
What is the composition of beach material depend on
Whatever is locally abundant
What travels in a wave
Energy
What are the characteristics of a wave
Trough crest wave period Wave height wavelength fetch whitecaps swells
What is the trough and crest of a wave
Trough = Bottom of the wave Crest = top of the wave
What is wave period And fetch
Wave period = Time it takes one wavelength to pass a fixed position
Fetch = Distance wind has traveled over open water
What is wave height and wavelength
Wave height = Crest to trough
Wavelength = Crest to crest
What are swells and whitecaps
Whitecaps = breakers when waves of water get to steep Swells = Any wave that has traveled out of its area of origin
What three factors affect height length and period
Wind speed
length of time Wind has blown
Fetch
How does water moving a wave
Circular orbital
What happens to the wavelength in the surf zone
It slows down
What happens when a wave becomes too high
It breaks and continues towards shore
What is Surf
Turbulent water created by breaking waves
What is swash and backwash
Swash = Turbulent sheet of water from collapsing breakers moving in a diagonal motion Backwash = Following theswash water flows straight back towards the surf zone
What happens because of wave refraction
Straighten an irregular shoreline
What is a dominant feature of high-energy waves
Wave cut cliff - vertical wall of exposed rock
What is Longshore transport
Zigzag motion that move sand down the beach
What are rip currents
Concentrated movements of water that flows opposite direction of breaking waves
Name erosional features
Wave cut cliff
Wave cut platform
Sea stack
Sea arch
What is a wave cut cliff and a wave cut platform
Wave cut cliff = Steep cliff along a shoreline
Wave cut platform = Flat almost horizontal surface
Draw a sea stack and a sea arch
http://www.tulane.edu/~sanelson/images/seastack.gif
Name depositional features
Spit baymouth bar Tombolo Beach barrier island
Draw a spit and baymouth bar
Spit - http://upload.wikimedia.org/wikipedia/commons/5/56/Provincetown_Spit_Cape_Cod.jpg
Baymouth Bar - http://classconnection.s3.amazonaws.com/747/flashcards/1184747/jpg/baymouthbar011331275061103.jpg
What is hard stabilization
Structures built to protect the coast from erosion or to prevent the movement of sand along the beach
What are groins
A series or a wall of rocks to prevent longshore drift from eroding the beach
http://4.bp.blogspot.com/_7QjkBSLD4nQ/SOXR5JK81yI/AAAAAAAAAMM/slNC-br2v4k/s400/EE+SeaWall+Sth+May+1987-500k.jpg
What are breakwaters
Artificial barriers for storm waves to strike
http://us.123rf.com/400wm/400/400/j0yce/j0yce1101/j0yce110100284/8629193-breakwater-wall-in-bar-harbor-maine-in-the-united-states-with-a-small-island-at-the-far-end.jpg
What are seawalls
On shore wall parallel to the shore to protect it from incoming waves
http://www.texasescapes.com/TexasGulfCoastTowns/GalvestonTexas/GalvestonTexasEndOfSeawall1908TXOPtb.jpg
What is the problem with hard stabilization structures
They don’t always work
What is beach nourishment
Adding large amounts of sand from another location to rebuild a beach
What is relocation
Relocating storm damaged or at risk buildings to let nature rebuild the beach
What causes tides
The moon and sun’s gravity and inertia
how many tides are there per day
2 low and 2 high tides
What is a springtide and when does it occur
Very high and very low tides
New or full moon
What is a neap tide and when does it occur
Small tidal range
When the sun and the moon are at right angles to each other/first and third quarter moons
