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Oceanography Prelim 1
Oceanography Prelim 1
141
Environmental Studies
Undergraduate 4
09/27/2015

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Term
Big Bang happened roughly ____________ years ago
Definition
15 billion
Term
At the time of the big bang, there was only ________ and _______ in the universe
Definition
hydrogen, helium
Term
Gravity pulls these two things together to form _______ elements through ________ ________
Definition
heavier, thermonuclear reaction
Term
These heavier elements are
Definition
carbon, nitrogen, phosphorous
Term
Larger stars exploding formed
Definition
gold, copper, etc
Term
our own sun is thought to be a _______ ________ ______
Definition
third generation star
Term
Roughly, there are _____ _______ galaxies with ______ _______ stars
Definition
100 billion, 100 billion
Term
temperatures in the core of large masses increase due to _____________ ______________
Definition
compressional heating
Term
Core temperatures at 10 million degrees kelvin cause ________ ___________ of H --> He
Definition
nuclear fusion
Term
nuclear fusion of H --> He
Definition
-thermonuclear fusion reaction
forms heat and visible light
Term
All _______, __________, and __________ atoms making up my current physical body were at one point sitting in the center of a boiling hot star
Definition
carbon, nitrogen, phosphorous
Term
Terrestrial planets build up by
Definition
multiple collisions and accretion of planetesimals
Term
giant outer planets grew by ______ ____________
Definition
gas accretion
Term
inner planets are:
Definition
-terrestrial
-relatively small
-contain the heavier elements (Fe, Si, O)
-rocky shell over a metallic core
-4.6 billion years old
Term
outer planets are:
Definition
-gaseous
-mostly volatile gases (H, He)
-same composition as the sun
Term
planetesimals
Definition
asteroids and comets. essentially, compositions of grain, matter
Term
__________ years ago, rock-forming elements condensed into small solid grains as _______ cooled
Definition
4.6 billion; nebula
Term
______ formed when Earth was hit by a Mars sized object (__________ years after Earth accreted)
Definition
Moon; 100 million
Term
______ ______ _______ makes 23 degree angle with _______ ______
Definition
earth spin axis; orbital plane
Term
early earth :
Definition
-atmosphere consisted of hydrogen and helium
-most of the gases lost to space
Term
modern Earth:
Definition
-out-gassing from volcanoes releases -- water, carbon dioxide, sulfur dioxide. N2, H2, Cl2
-water vapor condensed and precipitated to form oceans --> anaerobic life develops
-photosynthetic life evolves and this produces a modern oxygen rich atmosphere
Term
5 oceans
Definition
pacific, atlantic, indian, arctic, southern
Term
average depth of oceans
Definition
4 km
Term
_______ % of earth is water
Definition
70
Term
scale earth down to size of
Definition
beach ball
Term
in scaled down earth,
ocean thickness would be _____
atmospheric thickness would be ____
Definition
1.5 mm
4.5 mm
Term
______ _______ of the atmosphere's mass is within _____ ____ of the planetary surface
Definition
three quarters; 12 km
Term
Earth and sun are middle aged, both have about ____ ________ years of life left
Definition
4 billion
Term
Latitude runs ______ to _____, it is a measure of degrees from ________ and _______ _______ to a certain point.
Definition
East; West
Equator; global center
*equator is 0
Term
Longitude runs _______ to ______, it is a measure of degrees from ________ ________ and _______ ________ to a certain point
Definition
North, South
Prime Meridian; global center
*prime meridian is 0 (greenwich, england)
Term
Marine Geology
Definition
Term
Bathymetry
Definition
bottom depth
Term
single-bean sonar
Definition
creates a track line of bottom depth as the ship moves forward
Term
multi-beam sonar
Definition
creates a swath of bottom depth as the ship moves forward
Term
towed multi-beam sonar
Definition
creates a high resolution swath of bottom depth as the ship moves forward
Term
theory of continental drift
Definition
alfred wegener 1915
developed the idea of plate tectonics; not well accepted at the time despite overwhelming evidence.
Wegner had the wrong forcing mechanism of movement
Term
plate tectonic theory
Definition
was accepted after sea floor spreading and sea floor subduction were discovered in post WW2 exploration
Term
Earths's composition
Definition
-rigid outer crust (thin and rigid, floats on mantle)
-plastic upper mantle
-outer core (molten)
-inner core (solid)
Term
theory of plate tectonics:
Definition
steady accumulation of evidence leading to the birth of a new theory
Term
Alfred Wegener noticed apparent ____ _____ of continents as well as the ________________________
Definition
good fit;
distribution of fossil and mineral belts
Term
________ ___________ in ocean crust provided strong evidence of seafloor spreading
Definition
magnetic anomaly
Term
_______ __________ are a proxy measurement of geologic time--each __________________
Definition
magnetic anomalies;
anomaly can be assigned a specific geologic date
Term
Discover of deep sea trenches and associated seismic activity helped to explain:
Definition
the eventual loss of ocean crust that was initially formed at mid ocean ridges
Term
driving mechanism of plate tectonics:
Definition
convection in the mantle and slab pull
Term
oceanic crust
Definition
-thin: 5km
-relatively higher density
- consists of mostly basalt
-average density 3g/cm cubed
-thinner and only slightly less dense so they float lower in the mantle
Term
continental crust
Definition
-thick: 70 km
-has a relatively lower density
-consists mostly of granite
-average density - 2.7 g/cm cubed
-thicker and less dense so they float higher on the mantle
Term
________ ________ is created by divergent boudnaries
Definition
mid-ocean ridge
Term
convergent boundaries
Definition
oceanic and continental
oceanic and oceanic
continental and continental
Term
convergent boundaries: oceanic and continental
Definition
-deep ocean trenches
-explosive volcanoes
-subduction related volcanoes are particularly explosive and dangerous
-mount st helens
Term
convergent boundaries: oceanic and oceanic
Definition
-older plate goes under
-deep ocean trench
-chain of volcanoes = island arc
Term
convergent boundaries: continental and continental
Definition
mountains are formed
everest
Term
transform boundaries
Definition
plates slide laterally relative to one another
Term
sediment thickness is high near coast due to:
Definition
river runoff of terrigenous sediment and high productivity that leads to high rain rate of biological material
Term
red clays found in open ocean:
Definition
slow rain of continental dust
Term
________ or ___________ sediments found in high biological productivity regions
Definition
calcareous, siliceous
Term
rate of accumulation is very slow; 10 meter sediment core can =
Definition
millions of years
Term
proxy measurements of past ocean conditions:
Definition
-surface water conditions
-biological productivity
Term
most oxygen has mass of
Definition
16
Term
some oxygen has mass of 18
Definition
Term
proxy measure for temperature measurement is to use:
Definition
isotope ratio of oxygen preserved in shells of calcite fossils
Term
O18 is preferentially __________ from the water and incorporated into ______ _______ during growth
Definition
removed; calcite shells
Term
All things equal, calcite in shells grown in ______ _______ will have more O18 than calcite grown in _______ _______
Definition
colder temperatures; warmer temperatures
Term
we are currently experiencing a _______ mass extinction
Definition
6th
Term
Waves and Tides
Definition
Term
wavelength
Definition
crest to crest distance
Term
wave speed
Definition
distance a wave crest travels per unit time
Term
wave period
Definition
time it takes a wave crest to travel one wavelength
Term
wave frequency
Definition
number of crests passing a fixed location per unit of time
Term
waves propagate ______ but not ______
Definition
energy; mass
Term
Determinants of wave speed:
Definition
-wavelength
-bottom depth
Term
waves with longer wavelength travel _______ than waves with shorter wavelength
Definition
faster
Term
waves traveling in deeper water travel ________ than waves traveling in shallower water
Definition
faster
Term
under certain exceptional circumstances, __________________________ will be the primary determinant of wave speed
Definition
only wavelength or only bottom depth
Term
in very deep water, _________ determines wave speed
Definition
wavelength
Term
in very shallow water, ___________ determines wave speed
Definition
bottom depth
Term
deep water waves
Definition
-bottom depth is deeper that 1/2 the wavelength
-speed is a function of wavelength only
-more wavelength = more fast
Term
shallow water waves
Definition
-bottom depth is shallower than 1/20 the wavelength
-speed is a function of depth
-more shallow = more slow
Term
intermediate waves
Definition
speed is a function of both wavelength and bottom depth
Term
wave dispersion
Definition
self sorting of deep water waves leaving a storm region based on wavelength
Term
wave refraction
Definition
the bending of shallow water wave fronts due to change in bottom depth
(focusing and defocusing of wave energy on headlands and bays respectively)
Term
______ _______ is different in different seasons
Definition
sand movement
Term
summer (constructive waves)
Definition
gentle waves push offshore sandbar shoreward to create wide and gently sloping sandy summer beach
Term
winter (deconstructive waves)
Definition
storm waves drag sand off the beach to be stored in offshore sandbar, resulting in rocky winter beach
-steep beach
Term
rip currents
Definition
-initiated when large waves push water onto an elevated beach face
-seldom wider than about 10 meters
-can pull a person hundreds of meters offshore
Term
wave height determinants
Definition
wind speed, wind duration, wind fetch
Term
wave height determinants: wind speed
Definition
sets the upper possible limit on wave height for a fully developed sea
Term
wave height determinants: wind duration
Definition
modulates the upper possible limit on wave height
Term
wave height determinants: wind fetch
Definition
the distance over which wind can blow without obstruction
modulates the upper possible limit on wave height
Term
higher wind speed =
Definition
higher wave height
Term
______ in the open ocean is limited by the size of the storm system
Definition
fetch
Term
equilibrium model of tides =
Definition
highly idealized but instructive
-tide wave treated as a deep water wave in equilibrium
-no interference from continents
Term
diurnal
Definition
1 high tide and 1 low tide per day
Term
semidiurnal
Definition
2 equal high tides and 2 equal low tides per day
Term
mixed semidiurnal
Definition
2 unequal high tides and 2 unequal low tides per day
Term
tidal bulges created by the
Definition
pull of the gravity of the moon and centrifugal force
Term
tidal bulges are on ________ sides of the earth and case the _____________ over roughly a _________
Definition
opposite;
rise and fall of the tides;
24 hr period
Term
tide rises at
Definition
180 degrees
Term
tide falls at
Definition
90 degrees
Term
tidal day = 24 hr and 50 min
Definition
Term
moon orbit is inclined at ___________ which causes changes in _____________
Definition
28 degrees; the daily pattern of tides
Term
spring tides
Definition
-occur when the moon pulls along the same line as the sun
-occur on new and full moons
-relatively higher
Term
neap tides
Definition
-occur when the moon pulls at 90 degrees to the sun
-occur on first and last quarter moon
Term
daily patterns =
Definition
diurnal, semidiurnal, mixed semidiurnal
Term
monthly patterns =
Definition
spring, neap
Term
dynamic theory of tides--a more realistic view of tides:
Definition
-rotary tidal motion
-larger tidal ranges in coastal vs open ocean regions
-tide wave treated as a forced shallow water wave
-affected by the Coriolis force
-continents interfere with the propagation of the tide wave
Term
all ocean tides are pinched upwards from the ________________ on all the ocean
Definition
cumulative lateral pull by the moon
Term
_______ are not large enough to experience this, hence no tides
Definition
lakes
Term
tide waves are ______ _____ _____ _____
Definition
forced shallow water waves
Term
_________ __________ causes the high tide to occur sometime after the moon appears to pass overhead
Definition
frictional drag
Term
_______ ________ has a very significant effect on the direction of tidal propagation
Definition
Coriolis Force
Term
Coriolis always acts exactly to the ________ of the direction of motion in the northern hemisphere, and always directly to the ________ of the motion in the southern hemisphere
Definition
right; left
Term
Physical Oceanography
Definition
Term
Global surface wind patterns
Definition
easterlies, westerlies, trades
Term
contained within latitude bands
Definition
0-30
30-60
60-90
Term
ocean surface temperatures
Definition
-warmest near equator
-coldest near poles
Term
atmospheric convection and precipitation is strongest along ______________
Definition
the equator
Term
the weight of a column of air is ______ _________ to the average molecular weight of the mix of all molecules making up the air
Definition
directly proportional
Term
vertical distribution of density directly influences the ________________________
Definition
vertical movement of water in the ocean
Term
salt concentration and water temperature jointly determine _________ _________
Definition
seawater density
Term
surface ocean temp is determined by the ______________
Definition
exchange of heat between the ocean surface and the atmosphere
Term
ocean temp is a measure of ____________
Definition
the heat energy contained in the ocean
Term
when more energy than leaves the ocean surface, ________________.
converse is also true.
Definition
the surface warms
Term
__________ adds heat
Definition
sunlight
Term
________ _________ takes away heat
Definition
evaporative cooling
Term
all direct solar heating takes place _______________
Definition
very near the ocean surface (0-30m)
Term
permanent thermocline:
Definition
broad region centered at around 500 m where seawater temp changes from warm to uniformly cold
Term
seasonal thermocline
Definition
in some ocean regions, occurs in summer and is erased in winter
Term
seasonal pycnocline
Definition
a region of strong change in density with depth...comes and goes with net heat gains in spring and summer and net heat losses in fall and winter
Term
permanent pycnocline
Definition
remains in place at around 500 meters and is the result of the long term balance between the downward heating/mixing at the surface and upward mixing of cold water from below
Term
Ekman transport
Definition
a slab of surface ocean water (30-60m) moved by wind forcing
-due to wind force, friction force, and coriolis force
-moves at exactly 90 degrees to the direction of the wind forcing
Term
geostrophic currents
Definition
currents that move along lines of constant pressure
Term
geostrophic balance
Definition
the point at which currents move with steady speed with coriolis and pressure gradient forces in perfect opposition...results in geostrophic current
Term
subtropical gyre development
Definition
-westerly and trade winds drive the ekman layer to the center of the gyre to create a mound of surface water
-the push of coriolis turns the fluid until it travels along concentric lines of constant pressure (geostrophic balance)
Term
western boundary currents
Definition
-western side of subtropical gyres
-very swift and narrow
-bring warm water from the tropics to high latitudes
Term
eastern boundary currents
Definition
-eastern side of subtropical gyres
-broad and slow
-bring cold water from the high latitudes toward the tropics
Term
atlantic ocean temp at depth
Definition
-warm thin surface layer
-cold thick deep layer
-thermocline separates the warm and cold layers
Term
atlantic ocean salinity at depth
Definition
-high salinity in surface layer in subtropics
-deep ocean salinity more uniform and generally matches the surface salinity at higher latitude-especially northern high latitudes
Term
temp/salinity: NADW (North Atlantic Deep Water)
Definition
-labrador sea
-imminger sea
-greenland sea
-norwegian sea
Term
temp/salinity: AABW (antarctic bottom water)
Definition
-weddell sea
-rose sea
Term
temp/salinity: AAIW (antarctic intermediate water)
Definition
Term
global conveyer belt circulation:
Definition
combining the deep circulation and the wind-driven surgace circulation
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