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Definition of Oceanography
Known as marine science, it is the process of discovering unifying principles in data obtained from the ocea, its associated life forms, and its bordering lands.
Branches of Oceanography: Geological
Composition of innter earth the mobility of the crust the characteristics of seafloor sediments and the history of the Earth's Ocean
Branches of Oceanography: Physical Oceanographers
study and observe wave dynamics, currents and ocean-atmospheric interactions.
Branches of Oceanography: Chemical Oceanographers
Study the oceans dissolved solids and gases and their relationship to the geology and biology of the ocean as a whole
Branches of Oceanography: Biological
Work with nature and distribution of marine organisms, the impact of oceanic and atmospheric pollutants on organisms, the isolation of disease fighting drugs from marine species and the yields of fisheries.
Origin of the Ocean
Two theories: out gassing and water vapors came out of the earth to then rain down on it eventually creating an ocean or comets impacted earth from outer space that were carrying ice.
Origin of Life in the Ocean
organic materials came from comets which then mingled with the inorganic compounds. Forming building blocks for life the first living organisms were produced through biosynthesis.
Work of Matthew Maury
- -started depot of charts and insturments
- -read through old logs and documented weather locations
- -wrote a book called the physical geography of the sea
- -the "bible" of physical oceanography
- operated by the british navy
- steam engine
- 3 and 1/2 years and 80,000 miles of data collection of the depths of the ocean, currents, weather, sediment samples, and biological samples, 4717 species discovered
- 6 scientists named the science Oceanography
Developement of Echo Sounding
- Sound bounces over the sea floor, returns echo
- Can tell the depth while the ship is moving
- Still used today
- 1925-1926 german vessel
- deep sea drilling project
- Mineral deposits on the sea floor
- didnt make much money but it let to how the sea floor was formed, provided theories of seafloor spreading and plate techtonics
- Oceanography from satallites
- reads temp. with infared scanner
- didnt have it until 1970s
- 1978 seasat was the first satallite to have only the purpose of viewing the ocean
- measured chlorophyl from ocean color however satalites can only see the sea surface
True North vs Magnetic North
- true north is the axis of the earth's rotation
- magnetic north is the north the compass points to which is in greenland.
- 2' per year
- the rate at which the magnetic north moves towards the west.
the direction from one point to another, expressed as an angle relative to true north.
- expressed in defrees, is the intended direction of travel relative to true north.
- ex: 180 degrees means towards south
the direction toward which the ship is actually moving regardless of its intending course
Nautical miles vs Statute Miles
Nautical miles is one minute of latitude or 1.15 statute miles while statute miles are the miles we use everyday
Time zones are seperated hourly by how many degrees?
Greenwhich Mean Time
Coordinated Universal Time
4 Layers of the Earth
- outer core
- inner core
New Layers of the crust
- Lithosphere on top
- asthenosphere on bot
Evidence of earth inner layers
seismic waves from earthquakes indicated the interior of the earth wasnt solid since it passed through it much quicker
Earths outer layer which consists of about a dozen seperate major lithosperic plates
Evolution of theories of continental drift and seafloor spreading
- Wegener continental drift the continents were once together
- Mid ocean were spreading centers and the source of new ocean floor rising from the asthenosphere
- John Tuzo Wilson
- seafloor spreading + continental drift
- Convergent (subduction): Where plate push against one another, usually one subducts underneath another
- Divergent: spreading centers ocean ridges
- Transform: shearing crust is neither built or destroyed
geologic evidence confirming plate movement
- fossil record
- radiometric dating
- paleomagnetic stiping
- hot spots
difference between active and passive continental margins
- divergent= passive
shallow submerged extensions of a continent
the abrupt transition from continental shelf to continental slope
the transition between the gently descending continental shelf and the deep ocean floor
when the oceanic crust at the base of the continental slope is covered by an apron of accumulated sediment
underwater avalanches of sediments
5 deep ocean basin features
- mid ocean ridges
- abyssal plains
- abyssal hills: small sediment covered extinct volcanoes
- seamounts, guyots
how are sediments measured and sampled?
clamshell samplers, core sampler, they then take it out and refrigerate it.
- type of ecosounding
- can see different layers within the sediment
size of sediments
siliceous vs calcareous oozes
- siliceous are made from silica rish residues; diatoms
- calcareous are made from calcium containing minerals; cocolithophores
calcium carbonate compensation dpth
the rate at which the amount of calcareous sediments are being supplied to the seabed equals the rate it is dissolved
precipitation of dissolved minerals from water, often by bacteria
dust from space, meteorite debris
results of the tide draining out. looks like stream beds
lines of debris that mark the last of the high tide
caysed vt currents flowing over a sandy bottom when the tides are in. currents are more angular while waves are like hills
waves coming in at an angle and back another; look like diamonds
waves coming at an angle
Human Interference with Beaches 3 types
- making :
- importing sand
new coasts in which the dominant processes are those that remove coastal material
steady or growing because of their sediment accumulation rate or the action of living organisms