Oceans Midterm Flashcards
Oceanography?
Application of all science to study the oceans (interdisciplinary and collaborative)
Percent of Earth, ocean?
71%
Oceans what percent of water supply?
97%
What percent of US pop. lives within 50 miles of the ocean or Great Lakes?
Over 50%
Coastal development a problem?
yes
Important resource for…
oil, natural gas, metals, iodine, bromine, magnesium, phosphate, salt, sand, gravel, etc
How do oceans influence climate and weather?
they moderate the temp
Law of the Sea Treaty
first organized by U.N. in 1958, exclusive economic zone, regulate fishing, minerals, oil, safeguard environment, studies
US has the most EEZ
30% > US land area
Territorial waters
out 12 nautical miles
O: Chemical
seawater composition, chemical reactions, evolution of seawater, pollution, etc
O: Geological/Geophysics
ocean basins (origin, structure, sediments, coastlines, paleoclimate, magnetics), mineral resources
O: Physical
currents,waves, tides, temp, salinity, density
O; Biological
environment, critters, food chain
Ocean engineering
exploring for oil, exploitation, sea walls, oceans as an energy resource, naval architectures, marine policy
Posidonius
135BCE, Mediterranean was aprox 1000 fathoms deep
Magellon
early 1500s, Pacific > 600ft, found no bottom
Sir John Ross
1818, real success, Baffin Bay 6300ft
By 1500s, basic knowledge….
deeper water is colder, salinity varied a little, first submersible
Matthew Fountaine Maury
Founder of physical oceanography, organized currents, wind, weather info, made charts/maps, first bathymetric maps
First systematic ocean study US
6 ships, not well run, Albatros built to study oceans
Bathspheres
great depth, lowered on cable, tethered to surface
Bathyscaph
navigate, “Trieste” in mariana trench
2003 Integrated Ocean Drilling Program
initiated by US and Japan
Submersibles
by 1970 about 60 of them, most famous: Alvin
SONAR
“sound navigation and ranging”
Satellites
opex poseidan, determines sea level
GPS
location of ship, triangulation technique using 3 or more satellites, distance between receiver on earth
How many oceans are there?
3-5…(Atlantic, Pacific, Indian, Southern?, Arctic?
Properties of water
it can dissolve stuff, heats and cools more slowly than other liquids, density decreases when it becomes a solid
How many electrons to chemically bond?
8
Covalent or ionic bonds stronger?
covalent
Dipolar molecule
one side pos, one neg…but still neutral
latent heat
heat needed to change phases or states
To evaporate water totally, boil at?
100 degrees C
Can water gain/lose a lot of heat without changing temp?
yes
Rocks have a low or high heat capacity?
low
Marine/Lake effect
moderates temp
Continental effect
land has a greater day/night temp range and during seasons
Salinity
amount of dissolved ions or substances
S(parts per million) =
1.80655 x chlorinity (parts per million)
Salinometer
converts conductivity to salinity
Ocean salinity?
33 to 38 ppm
Salinity varies more at…?
coastal areas
greater evaporation =….
raised salinity
Sea water’s top two elements?
Chloride and Sodium
Residence time
avg length of time that something remain in the sea…(amount in sea)/(rate entering rivers
Oceans been around 3.4billion years, salinity has been constant for about?
1.5billion years
Addition of salt modifies seawater…
adding salt lowers freezing point
Density _____ with salinity
increases
3 of the main physical properties oceanographers use
temp, salinity, density
Density __ as temp __ and salinity __ and pressure __
raises, lowers, raises, raises
Isotherms
lines of equal temp
Salinity decrease
precipitation, runoff, ice melting
Salinity increase
evaporation
Pycnocline
rapid change in density, 18% of ocean basin
Deep layer
80% of ocean volume
Where did all the water come from?
volcanic activity, comets
Plate tectonics
greek: to build
Alfred Wegener
german climatologist and geophysicist
Pangea evidence..
fit of the continents, correlation across ocean basins, paleoclimate
Granite…
continental crust
Basalt…
oceanic crust
Oceanic plate…
thinner, denser, basalt comp.
Continental plate…
thicker, less dense, granite comp.
DIVERGENT
midocean ridges, processes: seasfloor formation, volcanism, high heat flow, earthquakes, BajaCali Mexico RedSea
CONVERGENT
A) continental oceanic, processes: seafloor recycled, earthquakes, volcanism.
B) oceanic oceanic, Japan Indonesia Philipines
C) continental continental, processes: mountain building, earthquake HimalayaMountains
Continental slope…
true edge of the continent, silt & clay, 4 degree av slope
Continental rise…
little relief, .5-1degrees, less than or equal to 10km thick
Abyssal plain…
very flat, sediment covering irregularities in basalt below,.,slumps, wind, critters, turbidity currents, (oceanic trenches trap sediment)
Mid-ocean ridge…
elevated because hot, 1000s km wide, pillow basalts
course->
high velocity high energy
fine->
lower velocity lower energy
Active Margins…
plate boundary and coastline coincide, convergent plate boundary, SF destroyed, earthquakes, volcanism, mountain building
Passive Margins…
coastline w/o plate boundaries, few earthquakes, no volcanism, no SF destruction, typically wide continental shelves, wide beaches, deltas, coral reefs
Transitional intersection of transform fault & coastline(margin)
no subduction zone, horizontal movement of faults, typically narrow shelf
Deep sea or oceanic trenches…
v-shaped, 1000s km long
Submarine canyons…
large v-shaped canyons, cut the slope rise and sometimes the shelf, perpendicular to shore, sometimes associated with rivers, formed by turbidity currents
Turbidity current…
dense slurry of mud and water, can be caused by slumping or earthquakes, brings sediments to abyssal plains, 10,000 years between turbidity currens
