Oceanography Final Part 1

Coriolis Effect, Strongest at the poles, nonexistent at the equator.

What causes ocean currents to curve?

Gyres

Circulating ocean currents caused by the Coriolis Effect.

• Occur in the surface or mixed layer and the pycnocline. 

• Only about 10% of all the ocean water

• Where gyres occur

• Distributes nutrients

• Able to collect marine debris

Describe the surface currents. 

Boundary currents

westward ones are fast, narrow, and deep.  Eastern ones are slow, wide, and shallow.

Geostrophic Flow

explains why there is a mound of water in the center of a gyre caused by the Coriolis effect.

Ekman’s Spiral

net movement of surface water is 90⁰ to the right

Upwelling

Is upwelling or downwelling associated with great fishing?

the Great Conveyor Belt

Surface and deep currents combine to form a global pattern of circulation that distributes heat and nutrients.

Tides

Caused by the gravitational force of the moon and Earth when they are aligned.

High

Is it high or low tide when the crest of a wave reaches shore?

24 hours and 50 minutes

How long is a lunar day?

6 hours and 12.5 minutes

If it is high tide now, how long until low tide?

12 hours and 25 minutes

If it’s high tide now, how long until it is high tide again?

Spring Tides

when the sun, moon, and Earth are all in a line the solar tide ADDS to the effect of the lunar tide.  Happens at the new moon and full moon phase.

Neap Tides

when the sun and the moon are at right (90^o) angles to each other, the solar tide partially cancels out the lunar tide and produces moderate tides.  Happens at the 1st and last quarter moon

Diurnal & location

• when there is only 1 high and 1 low tide each day. 

  • Gulf of Mexico and Alaska

Semi-diurnal & location

• when the 2 highs and 2 lows are about the SAME height.  

  • East Coast 

Mixed semidiurnal

•  when the 2 highs and 2 lows DIFFER in height.

  • West Coast

Gulf of Mexico because there is only 1 high and 1 low tide each day. 

Where is the best place in the U.S. to have a sand castle building competition and why?

Erosion

the wearing away and breaking up of rock and sediment

Deposition

building up the beach

Transportation

movement of sediment through longshore drift

longshore drift

Movement of sand/sediment along coasts by waves as it moves towards the coast at an angle. 

Summer is sandy, winter is rocky

Compare the appearance of beaches from summer to winter.

Headlands, arches, caves, stacks, and stumps

What are the erosional landforms found along the coast?

Beaches, Spits, Barrier Island, Lagoon, and tombolo

What are the depositional landforms found along the coast?

1. Gulf of Mexico (yards/year)

2. East/Atlantic (feet/year)

3. West/Pacific (inches/year)

Rank the U.S. coastlines by rate of erosion

Yes

Is coastal erosion a serious problem in the U.S.?

They are temporary solutions. None of these are more effective than the other.

What problems do beach renourishment, groynes, and seawalls share?