Term
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Definition
develop from friction between the ocean and the wind
Reflect average surface wind patterns
anticyclonic (clockwise) circular current gyres
located around prevailing high pressure centers |
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Term
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Definition
icebergs in the arctic ocean move at 90 degrees to the direction of the wind
Ekman's model to explain phenomenon
divides ocean into a series of thin layers |
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Term
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Definition
| large circular surface current pattern found in each ocean |
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Term
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Definition
masses of ocean water that flow from one place to another
amount of water can be large or small
currents can be at surface or deep
water masses in motion |
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Term
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Definition
The deflective force of earth's rotation on all free moving objects,
including the atmosphere and oceans.
deflection is to the right in northern hemisphere and
to the left in the southern hemisphere |
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Term
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Definition
current in which the coriolis force exactly balances gravity and the water is flowing parallel along the side of the mound in the direction of the wind
coriolis effect in northern hemisphere results in accumulation of light water on the right side of major surface currents
surface waters slide to the right, deeper water rises on the left side of current
produces considerable slope - the current velocity is proportional to the slope of the density contours
also causes a mounding up of water on the right side of currents...ocean surface has subtle topography |
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Term
| upwelling vs. downwelling |
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Definition
upwelling (divergence) - rise of cool nutrient water from depth
support large marine populations
occurs wherever different water masses are moving away from eachother or away froma coastline
downwelling (convergence) - sinking of surface water
occurs wherever surface currents are converging at sea or are impinging on a coastline |
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Term
| eastern vs. western boundary currents |
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Definition
EAstern: wEAker, shallower, slower
(CA, Canary)
wESTern: strongEST, on west side of all oceans
deep; flow along continental margins |
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Term
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Definition
temperature - salinity diagram
temperature, salinity, and pressure control sea density
isopycnals - lines of equal density
density increases from upper left to lower right |
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Term
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Definition
any point on a TS diagram
represents a homogeneous mass of water having well-defined temperature and salinity characteristics
two water types can have the same density, but much different temperature and salinity characteristics |
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Term
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Definition
when 2 or more water types mix together in the open ocean
for the mixing of 2 water types, the mass formed would be defined by a straight line connecting the two points (or water types) |
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Term
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Definition
North Atlantic Deep water:
formed by winter cooling of upwelling saline water around iceland.
piles up to ridge depth and flows out southward, rising again at antartic divergence
Antarctic Bottow Water:
densest, most widespread deepwater mass:found in atlantic, pacific, & indian
formed by cooling in polynyas (areas of free ice) around anarctica
freezing of ice increases salinity and density of this water |
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Term
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Definition
global circulation model
it takes approximately 1700 years for water to move along this path from the north atlantic to the north pacific
the water then moves back to the north atlantic via surfae and intermediate waters |
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Term
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Definition
| The maximum vertical displacement or the vertical distance from crest to trough |
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Term
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Definition
| The distance between two successive wave crests |
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Term
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Definition
| The time required for one complete wavelength to pass a given point |
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Term
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Definition
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Term
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Definition
| separate crests; low part |
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Term
| how are water waves formed? |
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Definition
Water waves are formed by winds blowing across the surface.
Waves form by the transference of energy from the wind to the water. |
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Term
| the height, length, and period of a wave depend on what factors? |
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Definition
wind speed
length of time the wind has blown
fetch
distance that the wind has traveled across open water |
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Term
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Definition
| the distance the wind has traveled across the open water |
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Term
| Capillary waves vs. Gravity waves |
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Definition
Capillary waves:
primary restoring force is surface tension due to hydrogen bonding
wavelengths <2cm
Gravity waves:
primary restoring force is gravity
wavelengths >2cm |
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Term
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Definition
as the wave travels, the water passes the energy along by moving in a circle
diameter of orbits decreases with depth |
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Term
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Definition
the depth of the water is greater than half the wavelength of the wave.
the longer the wave, the greater the speed
V = L / T,
Where V = wave velocity
L = wavelength
T = wave period |
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Term
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Definition
depth is less than half the wavelength of the wave
the shallower the water, the slower the wave
as waves enter shallow water, they continuously slow down
wave height increases |
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Term
| deep water vs. shallow water |
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Definition
deep water: depth of the water is greater than half the wavelength of the wave
shallow water: depth is less than half the wavelength of the wave |
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Term
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Definition
| long crested waves generated by winds that move away from the source area |
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Term
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Definition
| process by which the portion of a wave in shallow water slows, causing the wave to bend and tend to align itself with the underwater contours |
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Term
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Definition
| nearshore current that flows parallel to shore |
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Term
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Definition
The sediment within the surf zone is moved along by the longshore current
transport of beach material |
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Term
| When an obstruction (groin, pier, etc.) blocks the longshore current, where does sediment pile up and where does it erode? |
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Definition
pile up -upstream side
erosion -downstream side |
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Term
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Definition
As the wave begins to "feel the bottom", wave velocity and wavelength begin to decrease
Wave height begins to increase
wave form becomes steeper
waves become unstable and spill against the shoreline |
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Term
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Definition
process by which waves begin to sort themselves out as they travel out of their source area
longer wavelength waves move faster,
and move out in front of slower, shorter wavelength waves. |
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Term
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Definition
| only 1 high tide and 1 low tide of equal height every day |
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Term
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Definition
tides occur twice each tidal day
and are of about the same height |
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Term
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Definition
occur twice daily,
but the two high (or two low) tides
are of significantly different heights. |
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Term
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Definition
vertical distance between adjacent high and low tides
Tidal range also vary because of the elliptical nature of the moon's orbit around the earth |
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Term
| Spring Tides vs. neap tides |
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Definition
spring tides:
largest variations in tidal range
occur twice monthly
at the time of the new and full moon
neap tides:
smallest variations in tidal range
occur in conjunction w/1st & 3rd quarter phases of moon |
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Term
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Definition
| natural oscillations within the basin that affect the type of tide that occurs in an area |
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Term
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Definition
horizontal flow of water accompanying the rise and fall of the tides.
flood - tide rises
ebb current - tide falls
slackwater - little or no current |
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Term
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Definition
two highs, two lows
24 hours 50 minutes |
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Term
| equilibrium theory of tides |
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Definition
assumes a static ocean completely covering a smooth earth
considers only tide generating forces |
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Term
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Definition
land that is/has been affected by marine processes such as tides, winds, & waves,
even though direct effect of these processes may be felt only under extreme storm conditions |
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Term
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Definition
mosty dynamic area of the ocea
extends from outer limit of wave action on the bottom (seaward of lowest tide)
to the highest point on land reached by wave-transported sand |
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Term
| emergent vs. subergent coasts |
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Definition
emergent: coast is rising relative to sealeve
submergent: coast is falling relative to sea level |
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Term
| primary vs. secondary coasts |
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Definition
primary: process that occur at the land-air boundary
essentially unmodified by marine processes in the past 500 yrs
secondary: processes that are mainly of marine origin
erosion and marine deposition
spits, bars, barrier islands |
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Term
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Definition
elongated ridge of sand that projects from the land into the mouth of an adjacent bay
secondary coast feature |
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Term
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Definition
| sandbar that completely crosses a bay, sealing it off from the open ocean |
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Term
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Definition
| low, elongated ridge of sand that parallels the coast |
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Term
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Definition
| accumulation of sediment found along the landward margin of the ocean or lake |
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Term
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Definition
trap and retain sand moving parallel to the shore, nourishing the beach compartments between them
maintain and widen beaches |
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