Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
49 Cards in this Set
- Front
- Back
What are ocean currents?
|
Masses of ocean water that flow from one place to another.
|
|
How do surface currents develop?
|
From friction between the ocean and the wind that blows across its surface.
|
|
What are gyres?
|
huge circular-moving current systems.
|
|
What are the 5 main gyres?
|
North Pacific, South Pacific, North Atlantic, South Atlantic, Indian ocean.
|
|
The center of each gyre coincides w/ the subptropics at 30 degrees north and south latitude. So what are they called?
|
Suptropical Gyres
|
|
What is the Coriolis effect?
|
Deflection is tot he right in the Northern Hemisphere and to the left in the Southern Hemisphere.
|
|
What is upwelling?
|
The rising of cold water from deeper layers to replace warmer surface water.
|
|
What is thermohaline circulation?
|
Movements of ocean water caused by density difference brought about by variations in temperature and salinity.
|
|
What is the still water level?
|
Halfway between the crests and the troughs. Level the water would be if there were no waves.
|
|
What is wave height?
|
The vertical distance between trough and crest.
|
|
What is wavelength?
|
The horizontal distance between successive crests (or troughs)
|
|
What is the wave period?
|
The time it takes one wavelength to pass a fixed position.
|
|
The height, length, and period of a wave is achieved by what 3 factors?
|
1) wind speed
2) length of time the wind has blown 3) fetch |
|
What is fetch?
|
the distance that the wind has traveled across open water.
|
|
What is surf?
|
The turbulent water created by breaking waves.
|
|
What is wave base?
|
When the movement of water particles eventually becomes negligible as it gets at great depth.
|
|
What is abrasion?
|
The sawing and grinding action of the water.
|
|
What is wave refraction?
|
The bending of waves.
|
|
What is beach drift?
|
The transport of sediment in a zigzag pattern along a beach caused by the uprush of water from obliquely breaking waves.
|
|
What are longshore currents?
|
A nearshore current that flows parallel to the shore.
|
|
What are features called that owe their origin primarily to the work of erosion called?
|
erosional features
|
|
What are depositional features?
|
produced by deposits of sediment
|
|
What are wave-cut cliffs?
|
A seawater-facing cliff along a steep shoreline formed by wave erosion at its base and mass wasting.
|
|
What are wave-cut platforms?
|
A bench or shelf in the bedrock at sea level, cut by wave erosion.
|
|
What is a marine terrace?
|
A wave-cut platform that has been exposed above sea level.
|
|
What is a sea arch?
|
When two caves on opposite sides of a headland unite.
|
|
What is a sea stack?
|
When a sea arch eventually falls in leaving an isolated remnant.
|
|
What is a spit?
|
An elongated ridge of sand that projects from the land into the mouth of an adjacent bay.
|
|
What is a baymouth bar?
|
A sandbar that completely crosses a bay, sealing it off from the open ocean.
|
|
What is a tombolo?
|
A ridge of sand that connects an island to the mainland or to another island.
|
|
What is a barrier island?
|
A low, elongated ridge of sand that parallels the coast.
|
|
Interactions among different processes and the relative importance of each process depend on local factors. name 5 of them.
|
1. proximity of a coast to sediment laden rivers
2. the degree of tectonic activity 3. topography and composition of land 4. prevailing winds and weather patterns 5. configuration of coastline and nearshore areas. |
|
What is hard stabilization?
|
Structures built to protect a coast from erosion or to prevent the movement of sand along a beach.
|
|
What is a groin?
|
A barrier built to a right angle to the beach to trap sand that is moving parallel to the shore.
|
|
What is a breakwater?
|
A structure protecting a near shore area from breaking waves.
|
|
What is a seawall?
|
A barrier constructed to prevent waves from reaching the area behind the wall. Its purpose is to defend property from the force of breaking waves.
|
|
What is beach nourishment?
|
When large quantities of sand is added to the beach system to offset the losses caused by wave erosion.
|
|
What are emergent costs?
|
They develop either because an area experiences uplift or as a result of a drop in sea level.
|
|
What are submergent cost.
|
They are created when sea level rises or the land adjacent to the sea subsides.
|
|
What are estuaries?
|
A funnel-shaped inlet of the sea that formed when a rise in sea level or subsidence of land cause the mouth of a river to be flooded.
|
|
What are tides?
|
The daily changes in the elevation of the ocean surface.
|
|
What are spring tides?
|
The highest tidal range. Occurs near the new and full moons.
|
|
What are neap tides?
|
The lowest tidal range, occurring near the times of the 1st and 3rd quarters of the moon.
|
|
What is a diurnal tidal pattern?
|
A tidal pattern exhibiting one high tide and one low tide during a tidal day.
|
|
What is a semidiurnal tidal pattern?
|
A tidal pattern exhibiting two high tides and two low tidds per tidal day with small inequalities between successive high and low tides.
|
|
What is a mixed tidal pattern?
|
A tidal pattern exhibiting two high tides and two low tides per tidal day w/ a large inequality in high water heights, low water heights, or both.
|
|
What is the tidal current?
|
The horizontal flow of water accompanying the rise and fall of the tides.
|
|
What are tidal flats?
|
A marshy, muddy area that is covered and uncovered by the rise and fall of the tide.
|
|
What are tidal deltas?
|
A delta-like feature created when a rapidly moving tidal current emerges from a narrow inlet and slows, depositing its load of sediment.
|