Oceanography Final Flashcards
what is Oceanography?
the branch of earth science that studies all aspects of the marine environments
what are the four branches of oceanography?
geology, chemistry, physics, biology
what are the 5 ocean basins?
Pacific, Atlantic, Indian, Southern, Artic
what are the layers of earth?
crust, mantle, outer core, inner core
which crust is thick, lightweight, and made of granite?
continental crust
which crust is thin, dense, and made of basalt?
oceanic crust
which layer of earth is made of liquid?
outer core
what is the age of the earth vs the age of the oceanic crust?
4.6 bil vs 200 mil
who created the theory of Pangea and continental drift?
Alfred Wegner
what was evidence for alfred wegners theory?
same species found in different continents
advances in technology that provided evidence for plate tectonics include…
sonar maps of seafloor and magnetometer for magnetic field in oceanic crust
who created the seafloor spreading hypothesis?
Harry Hess
what is seafloor spreading?
Seafloor is created and the MOR moves away from mantle convection
where is youngest seafloor and oldest seaflooor located?
youngest at MOR and oldest in pacific
what is paleomagnetism?
seafloor records a record of recersals in earths magnetic field
how does paleomagnetism work?
magnetic minerals in lava align with the magnetic field
what is the wilson cycle?
formation of ocean basins and super continents
what are the stages of the wilson cycle and their locations?
Embryonic east africa, Juvenile mediterranean, Mature atlantic, Declining pacific, Terminal red sea, Suturing himilayas
what area of land sits on the mid atlantic ridge and hotspot?
Iceland
what are the 3 types of plate boundaries?
convergent, divergent, transform
what is a convergent boundary and where?
subducting, colliding, trenches in pacific
what is a divergent boundary and where?
MOR, new seafloor made, atlantic
what is a transform boundary and where?
nothing created/destroyed, san andreas fault
what drives plate tectonics?
mantle convection and slab pull
what are volcanic arcs formed by?
subduction
what are volcanic chains formed by?
hotspots
where is the ring of fire and what would you find there?
pacific ocean and volcanoes
what is a transform fault?
offset spreading along MOR, has shallow earthquakes, and plate boundary
what is a fracture zone?
extension of transform fault, no earthquake, no plate boundary
what is a hotspot?
a remained fixed spot where point sources magma, oceanic/continental
what makes up the tectonic (lithospheric) plates?
crust and brittle/rigid upper mantle
where do you find deep or shallow earthquakes?
deep=convergent, shallow=all three
what is the average spreed of sound in the ocean?
1500m/s
Mapping techniques include…
echo sounding, multi beam bathymetry, satellite altimetry, side scan sonar, multi channel
what is bathymetry?
measuring shape and depth of seafloor?
define countour
a line connecting points of equal value
what are the three major ocean provinces?
continental margin, deep ocean basin, mid ocean ridge
what are the characteristics of a continental margin?
shallow, close to shore
what are the characteristics of a deep ocean basin?
deep, far from land
what are the characteristics of a MOR?
submarine mountain range
what is a passive margin and where do you find it?
not a plate boundary, no tectonic activity, NE/atlantic coast
what is an active margin and where do you find it?
lots of tectonic activity, convergent/transform, Chile coast
what are the major features of a passive margin?
shelf, shelf break, slope, rise, plain
what is an eez?
exclusive economic zone
why are abyssal plains flat and where are they?
sea snow fills in between spaces and deep ocean basins
what is trench?
scars in floor that are narrow/deep, associated with subduction zones
what are features of an MOR?
transform faults/fracture zones, pillow basalts, hydrothermal vents
what are some hydrothermal vent organisms?
clams, mussels, tubeworms, bacteria
what is chemosynthesis?
hot water covered in chemcials that is absorbed by bacteria and uses the hydrogen sulfide
what are plankton?
floaters like diatoms radiolarians, copepods, jellyfish
what are nekton?
free swimmers like fish, whales, dolphins
what are benthos?
bottom dwellers like crabs, flounder, starfish
what is are the inputs of a sand budget?
sediments eroded from backshore cliffs by waves, brought by rivers, eroded from upcurrent beach by longshore drift
what are the outputs of a sand budget?
sediment moved to backshore dunes by offshore winds, water by tidal currents, down current by longshore drift
where is local sea level rise twice as fast?
chesepeak bay?
what is the average ocean salinity?
35 ppt
what is the recipe for a hurricane?
warm water evaporates, moist air condensation, coriolis effect
what are the major parts of a beach?
offshore, foreshore, backshore
what is a shoreline?
line that marks the contact between land and sea
what are some shoreline features?
barrier islands, spits, arches, cliffs
what is coastal erosion?
coast moves inland from sea level, beach moves with shoreline, beaches not eroded
what are four shoreline hardenings?
seawalls, groins, jetties, and breakwater
what are the four types of estuaries?
coastal plain, fjord, bar build, tectonic
what are the importance of wetlands?
they filter out toxins and nurse fish
what are the types of pollution?
petroleum, sewage sludge, trash, mercury, ddt
what are the 4 types of marine sediments?
terrigenous, biogenous, hydrogenous, cosmogenous
what does sediment texture tell us?
indicates depositional environment, distance/time of transportation process
what forms calcareous ooze?
foraminifera and coccolithophores
what forms siliceous ooze?
radiolarians and diatoms
what makes oozes?
at least 50% biogenic material and rest is clay
what are featuers of neritic sediments?
coarse grain, mostly terrigenous, turbidity currents
what are features of pelagic sediments?
finer grain, deposited slowly, volcanic ash/wind dust/abyssal clay
what are factors that control sediment distirbution?
productivity, destruction/dissolution, dilution
what are two factors that affect how much carbonic acid is in seawater?
pressure and temp
what is calcium carbonate (CaCO3) more soluable in?
deeper and colder water
define lyscoline
depth at which a significant amount of caco3 begins to dissolve rapidly
define CCD
calcite compensation depth wehre caco3 dissolves
where are the thickest sediments located?
continental shelves
where are the thinnest sediments located?
MOR
define paleoceanography
deciphering earth history by studying marine sediments
what are fecal pellets?
poop that reveals surface ocean conditions
what are 5 sediment collection methods?
dredge, grab sampling, gravity coring, piston coring, drilling
what are some resources from marine sediments?
oil/gas, methane hydrates, sand/gravel, manganese nodules, metal sulfides, salt
where would you find resources from the ocean?
continental shelves/margins
what is chalk made from?
coccolithophores
define albdeo
reflectivity of a surface 0-100%
define insolation
amount of solar energy reaching the surface of the earth
where is the source of all ocean and circulation from?
the sun
define coriolis effect
varies by latitude, caused by the rotationof the earth, deflection to right in north and left in south
what are the three global atmospheric circulation cells?
Hadley, ferrel, polar
what are the major wind belts?
trade winds, westerlies, polar easterlies
define air density
function of air temp and water vapor content/humidity
low pressure is from what?
warm, humid air rises
high pressure is from what?
cold, dry air sinks
wind moves from…
high pressure to low pressure
what drives local wind patterns?
heat capacity of rock vs water
what way do storms and hurricans rotate?
counterclockwise
what are the two major types of ocean circulation?
thermohaline and surface currents
defines surface currents
takes place in the mixed layer in the shallow ocean
what are surface currents measured by?
agro floats
what are surface currents modified by?
continents and Coriolis
what are gyres?
closed loops of warm and cool currents
what is upwelling?
cold, nutrient rich water from deep rises to surface
what is downwelling
warm, nutrient poor water from the surface sinks
what is density in the ocean dependent on?
temp, salinity, pressure
what are the water masses
nadw, aabw
define isothermal
one temperature
define isopycnal
one density
what are polar to
high latitude is less stratifide
what are polar oceans mixed like
well mixed with nutritents, oxygen, good for ecosystems
what are the Nino/as
short term climate flunctiations involving interactions between the ocean and atmosphere
W tropical pacific is…
sst drops, sea level drops, thermocline rises
E tropical pacific is…
sst rises, sea level up, thermocline deepens
what are the consequencess of el nino?
major shifts in planetary scale ocean/atmosphere circulations, collapse of fisheries
how are predicitons of el nino made?
deep sea moorings
define greenhosue effect
atmospheric gases absorb heat emitted from surface of earth
what are the effects of global warming?
shift in species distribution, more intense storms, changes in circulation, shift in rain/drought, rising sea level, ocean acidification
how do you change global sea level?
volume of water and thermal expansion of water
what do covalent bonds do?
share electrons
what do ionic bonds do?
opposite attract, give electrons
why is water so important?
capacity to store/release heat, forms of liquid solid gas
define latent heat
heat absorbed or released during state changes
define heat capacity
amount of heat required to raise the temp of 1g of any substance by 1 degree
define calorie
amount of heat required to raise temp of 1g of water by 1 degree C
ocean water is slightly what?
basic 7
what is ocean buffering?
ability of the oceans to maintain a near constant pH of 8.1 through chemical reactions that create or dissolve clacium carbonate
how much co2 does the ocean absorb?
33%
what zones are intertidal habitats?
sandy beach, salt marsh, rocky shore
what are bathypelagic fishes
bioluminescent fish
what features are at polar regions?
salinity lowers, lots of precipitation
what features are at mid-latitudes?
salinity higher, high rate of evaporation
what features are at the equator?
salinity lowers, lots of rain
