Intro to Oceanography FINAL
Home > Flashcards > Print Preview
The flashcards below were created by user
on FreezingBlue Flashcards
. What would you like to do?
Salinity of Ocean
Typical ocean salinity is 35 ppt
• Over a long period of time does the salinity of the ocean change from ~35ppt?
– No, even though salinity can build up from erosion, animals take up ions and convert them in to shells and other things which recycle the salts back in to the sediments.
– Salt spray along coastlines also removes salt. ~3.6 billion metric tons of salt removed annually
– Oceanic retreat from land leaves salt behind as well.
• Why is ocean water salty?
– Salts eroded from the crust of millions of years.
• How much salt is in the ocean?
– If dried and spread evenly, it would cover the world at a depth of 500ft.
Why does ice float on water?
– 9% less dense then water.
– Due to bond angles.
• Water has a bond angle of 104.5.
• Ice has a bond angle of 109.5.
– Ice takes up 9% more space then water.
A covalent bond is a chemical bond that involves the sharing of electron pairs between atoms. The stable balance of attractive and repulsive forces between atoms when they share electrons is known as covalent bonding.
pH of salt water
The pH of salt water is about 7-8
building blocks of all matter.
• Processes that decrease salinity?
– Icebergs (Glacial ice)
– Sea ice melting
Abrupt change of density with depth
How deep must you go to double the pressure?
• Why is the ocean blue?
• Reflection from the sky.
• Water absorbs colors differently depending on their wavelengths.
• Colors with shorter wavelengths get filtered out first, leaving those with longer wavelengths such as blue
Physical Properties of the Atmosphere
– Mostly nitrogen (N2) and Oxygen (O2).
– Other gases significant for heat trapping properties.
Weather at Wind Belts
• Lowest portion of circulation cells generate most of the wind belts.
• Trade winds
– From subtropical highs to equator.
– Northeast trades in Northern Hemisphere.
– Southeast trades in Southern Hemisphere.
• Prevailing westerlies
– from 30
–60 degrees latitude.
– Blow southwest to northeast in N. Hemisphere.
• Polar easterlies
–90 degrees latitude.
Boundaries between wind belts.
– Doldrums or Intertropical Convergence Zone (ITCZ)
– at equator.
• Regular rain fall
– Horse latitudes
– 30 degrees
– Polar fronts
– 60 degrees latitude.
• Regular precipitation
The Coriolis Effect
• Deflects path of moving object from viewer’s perspective
– To right in Northern Hemisphere
– To left in Southern Hemisphere
• Due to Earth’s rotation.
• Not a Force!
– Does not accelerate the moving body.
30 degrees latitude
Albedo, or reflection coefficient, derived from Latin albedo "whiteness" in turn from albus "white," is the diffuse reflectivity or reflecting power of a surface. It is the ratio of reflected radiation from the surface to incident radiation upon it.
30 degrees • Dry
the state of the atmosphere at a place and time as regards heat, dryness, sunshine, wind, rain, etc.
Saffir–Simpson hurricane wind scale
The Saffir–Simpson hurricane wind scale, or the Saffir–Simpson hurricane scale for short, classifies hurricanes
Tilt of Earth
• Earth’s axis of rotation is tilted 23.5° with respect to ecliptic.
– plane traced by Earth’s solar orb
Angular distance of Sun from equatorial plane
A gyre in oceanography is any large system of rotating ocean currents, particularly those involved with large wind movements.
• Average movement of seawater under influence of wind.
• 90 degrees to right of wind in Northern hemisphere.
• 90 degrees to left of wind in Southern hemisphere.
– Vertical movement of cold, nutrient
-rich water to surface.
– High biological productivity.
The Sargasso Sea is a region in the gyre in the middle of the North Atlantic Ocean
– Circulates around center of North Atlantic Gyre
– Unique biology
N. Atlantic Gyre
The North Atlantic Gyre, located in the Atlantic Ocean, is one of the five major oceanic gyres. It is a circular system of ocean currents that stretches across the North Atlantic from near the equator almost to Iceland, and from the east coast of North America to the west coasts of Europe and Africa.
• Antarctic Circumpolar Current
– Also called West Wind Drift and Penguin Gyre
– Pushed by westerly winds
• Roaring 40s
– Only current to completely encircle Earth • Due to lack of land.
– Moves more water than any other current
• Surface currents move at an angle to the wind.
• The Ekman spiral describes speed and direction of seawater flow at different depths.
• Each successive layer moves increasingly to the right in the Northern Hemisphere.
– Coriolis effect
– Vertical movement of surface water downward in water column.
– Generally low biological productivity.
– What benefit?
The North Pacific Gyre
The North Pacific Gyre, located in the northern Pacific Ocean, is one of the five major oceanic gyres. This gyre covers most of the northern Pacific Ocean.
A crest is the point on a wave with the maximum value or upward displacement within a cycle. A trough is the opposite of a crest, so the minimum or lowest point in a cycle.
Three Types of Breakers
– Water depth < 1/20 of wavelength
• Directly related to wave energy.
• Wave heights usually less than 2 meters (6.6 feet).
• Breakers called whitecaps form when wave reaches critical steepness.
• Beaufort Wind Scale describes appearance of sea surface.
• USS Ramapo (1933): 152-meters (500 feet) long ship caught in Pacific typhoon
• Waves 34 meters (112 feet) high
• Rogue waves:
– Freak waves that come out of nowhere.
– Created by constructive interference.
– Formed by the interaction of a wind wave and a swift surface current.
– Common in southeastern tip of Africa.
Still Water Level
Average water surface elevation at any instant, excluding local variation due to waves and wave set-up, but including the effects of tides, storm surges and long period seiches
• “Great wave in harbor”
• Seismic sea waves
– Earthquakes, landslides, volcanoes
• Can travel at speeds close to 500mph.
the time it takes one full wave—one wavelength—to pass a fixed position.
• Associated with pycnocline.
• Larger than surface waves.
• Caused by tides, turbidity currents, winds, ships.
• Possible hazard for submarines.
– In-phase wave trains with about the same wavelengths.
a true tidal wave.
• Wall of water that moves upriver.
• Caused by an incoming high tide. • Occurs in some low-lying rivers.
• Can be large enough to surf or raft.
Moon furthest from Earth
Bay of Fundy
The Bay of Fundy is a bay on the Atlantic coast of North America, on the northeast end of the Gulf of Maine between the Canadian provinces of New Brunswick and Nova Scotia, with a small portion touching the U.S. state of Maine.
• Center-seeking force
• Tethers Earth and Moon to each other
– Quarter moons.
– Tidal range least.
24 hr 50 min cycle
Semi Diurnal Tide
12 hr 25 min cycle
A whirlpool is a swirling body of water produced by the meeting of opposing currents. The vast majority of whirlpools are not very powerful.
between Moon and Earth.
a tide just after a new or full moon, when there is the greatest difference between high and low water
a narrow, variable band of very strong, predominantly westerly air currents encircling the globe several miles above the earth. There are typically two or three jet streams in each of the northern and southern hemispheres.
a seasonal prevailing wind in the region of South and Southeast Asia, blowing from the southwest between May and September and bringing rain (the wet monsoon ), or from the northeast between October and April (the dry monsoon ).the rainy season accompanying the wet monsoon.
El Niño is a band of anomalously warm ocean water temperatures that periodically develops off the Pacific coast of South America.
Only current to circumnavigate the globe
Arctic circumpolar current
weather at horse latitudes
dry with little wind
convection cell from 30 to 60 degrees
Length of lunar day
25 hrs 50 min
Result of too much carbon in the ocean
wave created by seismic activity
Western gyres are _____ and_____ than
faster, deeper than eastern gyres
Two forces causing tides
Centripetal force and gravity
Time between 2 successive waves
waves created by different densities
2 opposing currents create
Location of great garbage patch
North Pacific gyre
Most dense body of water
Antartic Bottom water
In phase waves coming together
Angular distance of orbital plane to equator
Common center of mass
Bond between atoms of a single water molecule
9% less dense than water
Three types of breaks
plunging, spilling, surging.
Tide with largest tidal range
True tidal wave
Average salinity of ocean water
Deflecting air masses left or right
Disruption of the walker cell
El nino event
Large waves created by swift currents
2 primary salts
sodium, and chloride
4 boundaries of North Atlantic Gyre
Canary, Equatorial, Gulf, N. Atlantic
Term for 1/4 moon and neep tides
Reflective of a surface
Most common gas in atmosphere nitrogen
Circular pattern in major ocean basins
Weather at maritime tropical area
warm and wet
Average movement of water with the wind
Narrow fast easterly wind
when moon is furthest from earth
three factors that wave height is dependent on
wind duration, speed, fetch
surface water pushed up
location with largest tidal range
Bay of Fundy
ratio at which a wave breaks
sea surrounded by four ocean currents
The force that pulls an orbiting body toward the center of that orbit is called
Convection cell from 0 to 30 lat
Fish that uses tides for reproduction
Building block of all matter
Process that decreases salinity
Precipitation, runoff, ice melting
Average water surface level
Water surface level
What would you like to do?
Home > Flashcards > Print Preview