Oceanography Flashcards
atoll
an island consisting of a circular coral reef surrounding a lagoon
barrier reef
A reef separated from the shoreline by the deeper water of a lagoon.
continental arc
mountains formed in part by volcanic activity caused by the subduction of oceanic lithosphere beneath a continent
continental drift
the hypothesis that the continents slowly move across Earth’s surface
continental transform fault
fault that cuts across a continent
convection cell
A circular pattern of air rising, air sinking, and wind.
convergent boundary
a plate boundary where two plates move toward each other
coral reef
diverse and productive environment named for the coral animals that make up its primary structure
divergent boundary
a plate boundary where two plates move away from each other
east pacific rise
oceanic rise between pacific and nazca plate. broad, low, gentle swelling of the sea floor with a small, indistinct central rift valley
fringing reef
A reef attached to the shore of a continent or island.
great barrier reef
largest coral reef in the world Austrailia
guyot
Flat-topped seamount (volcano)
hawaiian islands - emperor seamount chain
Island chains in the northern Pacific Ocean.
Harry Hess
developed the theory sea-floor spreading- ocean floors move like conveyor belts, carrying the continents along with them
hot spot
a concentration of heat in the mantle capable of producing magma, which rises to Earth’s surface; The Pacific Plate moves over a hot spot, producing the Hawaiian Islands
ice age
any period of time during which glaciers covered a large part of the earth’s surface
island arc
A string of islands formed by the volcanoes along a deep ocean trench
magnetic anomaly
evidence that the ocean floor is spreading apart. It shows that the earth’s magnetic field has reversed several times throughout the earth’s history
magnetic field
the area of magnetic force around a magnet
mantle plume
A mass of hotter-than-normal mantle material that ascends toward the surface, where it may lead to igneous activity.
mesosauras
an example of a species that helped support the continental drift hypothesis
mid-atlantic ridge
a long, continuous underwater mountain range, formed by volcanic outpourings from the asthenosphere, that lies roughly parallel to continental margins; the center is marked by a steep V
mid-ocean ridge
an underwater mountain chain where new ocean floor is formed
ocean trench
deep valley in the ocean floor that forms along a subduction zone
ocean ridge
A massive mountain range laying at the bottom of the sea. such as mid-atlantic
ocean rise
fast- spreading, gentle slopes
oceanic transform fault
A fault with side-to-side motion that offsets segments of a mid-ocean ridge. This kind of transform fault occurs wholly on the ocean floor.
paleomagnetism
The study of the alignment of magnetic minerals in rock,specifically as it relates to the reversal of Earth’s magnetic poles; also the magnetic properties that rock requires during formation
Pangaea
large, ancient landmass that was composed of all the continents joined together
polar wandering curve
magnetic pole was wandering or moving through time
polarity
the directional orientation of the magnetic field
rift valley
a deep valley that forms where two plates move apart.
rifting
The process of a landmass splitting apart
san andreas fault
a major geological fault in California
sea floor spreading
when two oceanic plates pull apart, magma rises and new crust is formed harry hess
seamount
an underwater mountain rising above the ocean floor cone shaped
spreading center
The region at the crest of a mid-ocean ridge, where new crust is being formed by seafloor spreading.
subduction
a geological process in which one edge of a crustal plate is forced sideways and downward into the mantle below another plate
subduction zone
the region where oceanic plates sink down into the asthenosphere
transform boundary
a plate boundary where two plates move past each other in opposite directions
transform fault
tectonic plates sliding past one another (ex. San Andreas fault).
transform faulting
movement of one plate past another-produces shallow but often strong earthquakes in the lithosphere
Frederick Vine
A geologist who, along with Drummond Matthews, combined the seemingly unrelated pattern of magnetic sea floor stripes with the process of sea floor spreading to explain the pattern of alternating and symmetric magnetic stripes on the sea floor.
volcanic arc
a chain of volcanic islands generally located a few hundred kilometers from a trench where there is active subduction of one oceanic plate beneath another
Alfred Wegner
scientist who came up with the continental drift theory
abyssal hill
A hill on the slope of a mid-ocean ridge about 100m high and lineated parallel to the ridge crest, formed by faulting of the basaltic oceanic crust as it moves out of the rift valley
abyssal plain
a large, flat, almost level area of the deep-ocean basin
active margin
located in areas where oceanic lithosphere is being subducted beneath the leading edge of the continent
bathymetry
measuring the depths of the oceans
black smoker
temps above 350 and emits water that is black containing metal sulfides
continental arc
Mountains formed in part by volcanic activity caused by the subduction of oceanic lithosphere beneath a continent. (Andes Mountains)
continental margin
The shallow sea floor that is located between the shoreline and the deep-ocean bottom
continental rise
transitional sloping surface at the base of the continental slope
continental shelf
The part of a continent that extends underwater, generally flat zone before the slope
continental slope
a steep incline of the ocean floor leading down from the edge of the continental shelf
convergent active margin
An active margin associated with oceanic-continental convergent plate boundaries.
deep-ocean basin
the part of the ocean floor that is under deep water beyond the continent margin and that is composed of oceanic crust and a thin layer of sediment
deep-sea fan
A cone-shaped deposit at the base of the continental slope. The sediment is transported to the fan by turbidity currents that follow submarine canyons., a cone-shaped deposit at the base of the continental slope. the sediment is transported to the fan by turbidity currents that follow submarine canyons
fathom
standard unit of ocean depth
fracture zone
similar to transform faults
graded bedding
sediments of different sizes and shapes settle to different levels
hypothermal vent
underwater openings from which hot, mineral-rich water flowed, where metabolic reactions began, minerals were deposited forming rocks with tiny chambers, the iron sulfide would donate hydrogen and electrons to dissolved CO2, forming organic molecules
island arc
A string of islands formed by the volcanoes along a deep-ocean trench. Islands of Japan
ocean trench
deep valley in the ocean floor that forms along a subduction zone
ocean rise
slopes that are gentler/less rugged
pacific ring of fire
occurs along the margins of the Pacific Ocean
passive margin
Embedded within the interior of the lithospheric plate
pillow basalt
smooth rounded lobes of rocks which resemble pillows
pillow lava
smooth rounded lobes of rocks which resemble pillows
precipitate
disolved metal particles mixed with cold seawater
shelf break
the outer edge of the continental shelf
submarine canyon
A deep, V-shaped valley running roughly perpendicular to the shoreline and cutting across the edge of the continental shelf and slope.
submarine fan
deposits at the bottom of the submarine canyons
transform active margin
associated with transform plate boundaries-create linear islands, banks, and deep basins close to shore (San Andreas Fault)
turbidite deposit
stacks of graded bedding of which continental rise is composed
turbidity current
Underwater “Avalanche” of abrasive sediments thought responsible for the deep sculpturing of submarine canyons and as a means for sediments accumulating on an abyssal plain
warm water vent
Have water temperatures below 30C and generally emit water that is clear in color.
white smoker
temps from 30-350C; precipitate barium sulfide
acid
compound that releases hydrogen ions when disolved in water
alkaline
a substance that releases hydroxide ions (OH) in a solution. Also called basic.
atom
basic building blocks of all matter
boiling point
the temperature at which a substance changes from a liquid to a gas
brackish
low salinity water caused by the mixing of freshwater and saltwater
calorie
unit of heat defined as the quantity of heat required to raise the temperature of 1 gram of water by 1 degree centigrade at atmospheric pressure
chlorinity
the amount of chloride ion and ions of other halogens in ocean water expressed in parts per thousand by weight
cohesion
the intermolecular attraction by which the elements of a body are held together
condensation point
the temperature at which a gas becomes a liquid.
condense
undergo condensation
covalent bond
a chemical bond that involves sharing a pair of electrons between atoms in a molecule (H2O)
deep water
The water beneath the permanent thermocline (and resulting pycnocline) that has a uniformly low temperature.
dipolar
Having two poles. The water molecule possesses a polarity of electrical charge with one pole being more positive and the other more negative in electrical charge.
electron
negatively charged particle; located outside the atomic nucleus
evaporation
the process by which a liquid changes into a vapor
freezing point
The temperature at which a liquid changes into a solid
halocline
a layer of water in which a high rate of change in salinity in the vertical dimension is present
heat
energy moving froma a high temperature system to a low temperature system
heat capacity
The amount of heat required to raise the temperature of a specified amount of a substance by 1°C or 1 K.
hydrogen bond
an intermolecular bond that forms within water because of the dipolar nature of water molecules
hydrologic cycle
the cycle of water exchange among the atmosphere, land and ocean through the processes of evaporation, precipitation, runoff and subsurface percolation. Also called the water cycle
hypersaline
waters that are highly or excessively saline
ion
atom that has a positive or negative charge
ionic bond
a chemical bond formed as a result of the electrical attraction
latent heat of condensation
the heat energy that must be removed from one gram of substance to convert it from a vapor at a given temperature below its boiling point. For water its 585 calories at 20 degrees C
latent heat of freezing
the heat energy that must be removed from one gram of substance at its melting point to convert it to a solid. For water it is 80 calories
latent heat of melting
the heat energy that must be added to one gram of a substance at its melting point to be converted into a liquid. For water it is 80 calories
latent heat of evaporation
the heat energy that is added to one gram of a liquid substance to convert it to a vapor at a given temp below its boiling point.
latent heat of vaporization
the heat energy that must be added to one gram of a substance at its boiling point to convert it to a vapor.
melting point
the temperature below which a liquid turns into a solid
mixed surface layer
the surface layer of the ocean water mixed by wave and tide motions to produce relatively isothermal and isohaline conditions
molecule
Two or more atoms held together by covalent bonds
neutral
a state in which there is no excess of either the hydrogen or hydroxide ion
neutron
an electrically neutral particle found in the nucleus of an atom
nucleus
composed of protons and neutrons
parts per thousand
how salinity is measured, is abbriviated PPT
polarity
having an indicated pole (as the distinction between positive and negative electric charges)
principle of constant proportions
Proportions of major conservative elements in seawater remain nearly constant, though salinity may change w/ location
proton
a subatomic particle that has a positive charge and that is found in the nucleus of an atom
pycnocline
a layer of water in which there is a rapid change of density with depth
residence time
The average time a given particle will stay in a given system
reverse osmosis
A desalinization process that involves forcing salt-water through a membrane permeable to water but not to salt
runoff
water that runs into the ocean causing the salinity to decrease
salinity
the relative proportion of salt in a solution
salinometer
An electronic device that determines salinity by measuring the electrical conductivity of a seawater sample.
specific heat
the amount of heat required to raise the temperature of 1g of a substance 1 degree Celsius
surface tension
the tendency for the surface of a liquid to contract owing to intermolecular bond attraction
temperature
the degree of hotness or coldness of a body or environment (corresponding to its molecular activity)
thermocline
a layer of water in which there is a rapid change in temperature with depth.
vapor
Describes the gaseous state of a substance that is generally a liquid or solid at room temperature
subtropical gyre
a large, circular-moving loop of water that is centered at about 30 degrees latitude and is initiated by the trade winds and the prevailing westerlies
western boundary currents
poleward-flowing warm currents on the western side of all subtropical gyres
Ekman Spiral
theoretical consideration of the effect of a steady wind blowing over an ocean of unlimited depth and breadth and of uniform viscosity; result is a surface flow of 45 degrees to the right of the wind in the Northern Hemisphere
Ekman Transport
the net transport of surface water set in motion by wind; it is theoretically in a direction of 90 degrees to the right and 90 degrees to the left of the wind direction in the Northern and Southern Hemisphere
western intensification
pertaining to the intensification of warm western boundary currents of each subtropical gyre that are faster, narrower, and deeper than their corresponding eastern boundary currents
upwelling
process by which deep, cold, nutrient-laden water is brought to the surface, usually by diverging equatorial currents or coastal currents that pull water away from a coast
downwelling
in the open or coastal ocean, where Ekman transport causes surface water to converge or impinge on the coast, surface water that moves down beneath the surface
coastal upwelling
movement of deeper nutrient-rich water into the surface water mass as a result of windblown surface water moving offshore
coastal downwelling
wind blows water toward coastline, surface water forced downward, gases and nutrients go to deeper waters
Gulf Stream
the high-intensity western boundary current of the North Atlantic Subtropical Gyre that flows north off the East Coast of the U.S.
Sargasso Sea
a region of convergence in the North Atlantic lying south and east of Bermuda where the water is very clear, deep blue color, and contains large quantities of floating Sargassum
California Current
the cold eastern boundary current of the North Pacific Subtropical Gyre
El Niño
a southerly flowing warm current that generally develops off the coast of Ecuador around Christmas time
La Niña
an occurrence in the Pacific in which trade winds increase, ocean temperatures decrease, and marine life flourishes
Southern Oscillation
the periodic change in the pressure differential between the Southeastern Pacific high pressure and the Western Pacific equatorial low pressure that occurs in concert with El Nino-Southern Oscillation events
thermohaline circulation
the vertical movement of ocean water driven by density differences resulting from the combined effects of variations in temperature and salinity; produces deep currents
Antarctic Bottom Water
a water mass that forms in the Weddell Sea, sinks to the ocean floor, and spreads across the bottom of all oceans
Antarctic Intermediate Water
Antarctic zone surface water that sinks at the Antarctic convergence and flows north at a depth of about 900 meters beneath the warmer upper-water mass of the South Atlantic Subtropical Gyre
west wind drift
Another name for the Antarctic Circumpolar Current or the penguin gyre
crest
The portion of an ocean wave that is displaced above the still-water level
Pacific Tsunami Warning Center
coordinates information from 25 Pacific Rim countries and is headquarted in Ewa Beach, Hawaii.
plunging breaker
Impressive Curling breakers that form on moderately sloping beaches. (best for surfing)
refraction
The process by which the part of a wave in shallow water is slowed down, causing the wave to bend and align itself nearly parallel to the shore
rogue wave
An unusually large wave that usually occurs unexpectedly amid other waves of smaller size. Also known as a superwave
spilling breaker
A type of breaking wave that forms on gently sloping beach, which gradually extracts the energy from the wave to produce a turbulent mass of air and water that runs down the front slope of the wave
still water level
The horizontal surface halfway between crest and trough of a wave. If there were no waves, the water surface would exist at this level. Also known as zero energy level
surf zone
The nearshore zone of breaking waves
trough
The part of an ocean wave that is displaced below the still-water line
tsunami
A seismic sea wave. A long-period gravity wave generated by a submarine earthquake or volcanic event. Not noticable on the open ocean but builds up to great heights in shallow water
wave base
The depth at which circular orbital motion becomes negligible. It exists at a depth of one-half wavelength, measured vertically from still water level.
wave dispersion
The separation of waves as they leave the sea area by wave size. Larger waves travel faster than smaller waves and thus leave the sea area first, to be followed by progressively smaller waves
wave height
(H) The vertical distance between a crest and the adjoining trough
wave period
(T) The elapsed time between the passage of two successive wave crests (or troughs) past a fixed point. A wave’s period is the inverse of its frequency
wave reflection
A vertical barrier, such as seawall a rock or ledge can reflect waves back into the ocean w/ little loss of energy–a process called__________
wave speed
(S) The rate at which a wave travels. It can be calculated by dividing a wave’s wavelength (L) by it’s period (T)
wave steepness
Ratio of wave height (H) to wavelength (L). If a 1:7 ratio is ever exceeded by the wave, then the wave breaks.
wave train
A series of waves from the same direction. Informally known as a wave set
wavelength
(L) The horizontal distance between two corresponding points on successive waves, such as from crest to crest.
frequency
the number of wave crests passing a fixed location per unit of time
formula for frequency (f)
1 / period (T)
formula for wave speed (S)
wavelength (L) / period (T)
formula for wave base
1/2 wavelength
formula for wave steepness
wave (H) / wavelength (L)
tides
The periodic raising and lowering of sea level that occurs daily throughout the ocean.
gravitational force
The force that makes every object that has mass in the universe be attracted to every other object.
What is the equation for the force of gravity?
Fg= ((G)(m1)(m2))/r squared
Why is the Lunar day 50 min longer than the solar day?
During the 24 hours it takes Earth to make a full rotation, the Moon has continued moving another 12.2 degrees to the east in its orbit around the Earth. Thus, Earth must rotate an additional 50 in to “catch up” to the moon.
flood tide
Water moving toward the shore.
ebb tide
Water moving away from the shore.
new moon
Phase in which the Moon is between earth and the Sun, it cannot be seen at night.
full moon
Phase in which the Moon is on the side of Earth opposite the Sun, its entire disk is brightly visible.
quarter moon
Phase in which the moon tat is half lit and half dark is viewed from the Earth, occurs when the Moon is at right angles to the Sun relative to Earth.
tidal range
The vertical difference between high and low tides
spring tide
The maximum tidal range
neap tide
When there is destructive interference between the lunar and solar tidal bulges.
waxing crescent
As the moon progresses from new moon to first-quarter phase.
waxing gibbous
In between the Moon’s full and third quarter phase.
waning gibbous
Between the moon’s full and third quarter phase
waning crescent
In between the third quarter and the new moon phase
diurnal tidal pattern
Has one high tide and one low tide each lunar day., a tidal pattern exhibiting one high tide and one low tide during a tidal day; a daily tide
semidiurnal tidal pattern
Has two high tides and two low tides each lunar day.
mixed tidal patterns
May have characteristics of both diurnal and semidiurnal tides.
Bay of Fundy
The largest tidal range in the world, found in Nova Scotia, with a length of 258 kilometers.
flood current
Produced when water rushed into a bay (or river) with an incoming high tide.
ebb current
Produced when water drains out of a bay (or river) with an incoming high tide.
Newton’s law of universal gravitation
states that every object that has mass in the universe is attracted to every other object
tidal bore
a wall of water that moves up certain low lying rivers due to an incoming tide
