Oceanography Mod 1 Flashcards
Scientific Method
Observe, Hypothesis, Testing, Theory
Hypothesis
testable statement about the general nature of the phenomenon observed
Theory
well-substantiated explanation of some aspect of the natural world that can incorporate facts, logical inferences, and tested hypothesis
Solar System
the sun and the celestial bodies, asteroids, planets, and comets that orbit around it
Nebula
a diffuse mass of interstellar dust and/or gas
Nebular Hypothesis
a model that describes the formation of the solar system by contraction of a nebula
Oceanography
scientific study of the floor of the ocean, the water itself, physical processes such as waves and tides, and the organisms contained within the ocean
Half-life
time required for half the atoms of a sample of a radioactive isotope to decay to an atom of another element
Heterotrophs
organisms not capable of producing their own food by photosynthesis
Autotrophs
anything that can synthesize organic compounds from inorganic nutrients
Prince Henry the Navigator
funded the exploration of the coast of Africa and the islands of the Atlantic Ocean
Christopher Columbus
Founded the “New World” by going west instead of east to india
Magellan
Named the Pacific ocean, traveled west to find the east indies
97.2%
How much of the world’s water is contained in oceans?
70.8%
How much of the world is made up of water?
Pacific Ocean
Largest ocean named by magellan, half the ocean surface
Atlantic Ocean
half the size of the pacific, separates new world from old world
Indian Ocean
slightly smaller than atlantic, southern hemi
Arctic Ocean
7% the size of indian ocean, not very deep
Southern/Antarctic Ocean
southern hemi, located below 50 degrees S and around antarctic
People of Pacific Islands
First people to arrive on NA continent
Sea
Smaller than other, contains salt water, somewhat enclosed by land
Lithosphere
cool, rigid, outer-most layer
Asthenosphere
plastic, flow when gradual force acted upon it
Mesosphere
rigid, increased pressure
Outer core
liquid and capable of flowing
Inner core
rigid and does not flow
Oceanic crust
Basalt, more dense, 5-10km thick,younger/newer
Continental crust
less dense, mostly made of granite, 30-50km thick, older
Stanley Miller
gave us an idea of how life could have developed out of non-living matter, a process called abiogenesis
4.5 Billion years
How old is the earth
Radiometric Dating
calculates an age in years for geologic materials by measuring the presence of a short-life radioactive element
James Cook
He mapped lands from New Zealand to Hawaii in the Pacific Ocean
Eratosthenes
invented a system of longitude and latitude and made a map of the known world
Plate tectonics
large slabs of rock that divide Earth’s crust, move constantly to reshape the Earth’s landscape
Continental drift
the movement of continents resulting from the motion of tectonic plates
Pangaea
North America was contiguous with Africa, South America, and Europe. They all existed as a single continent
Mid-Ocean ridge
seafloor mountain system formed by plate tectonics
Oceanic trench
long, narrow depressions on the seafloor
Subduction/Subduction zone
form where a plate with thinner (less-buoyant) oceanic crust descends beneath a plate with thicker (more-buoyant) continental crust
Paleomagnetism
the study of ancient pole positions and makes use of remanent magnetization to reconstruct the direction and strength of the geomagnetic field in the past
Rift valley
a lowland region that forms where Earth’s tectonic plates move apart, or rift
Hot spots
an area of the Earth’s mantle from which hot plumes rise upward, forming volcanoes on the overlying crust
Tablemounts/Guyots
an isolated underwater volcanic mountain (seamount) with a flat top more than 200 m (660 ft) below the surface of the sea
Seamounts
an underwater mountain with steep sides rising from the seafloor
Fringing reef
grows seaward directly from the shore
Barrier reef
running parallel to the shore but separated from it by a channel of deep water
Atoll
a coral island consisting of a reef surrounding a lagoon
Fracture zone
linear feature on the ocean floor—often hundreds, even thousands of kilometers long—resulting from the action of offset mid-ocean ridge axis segments
Paleogeography
the study of historical geography, generally physical landscapes
Alfred Wegener
originator of continental drift hypothesis
Harry Hess
known for his theories on sea-floor spreading and convection currents in the mantle driving plate tectonics
Frederick Vine & Drummond Matthews
found that the crust surrounding the midocean ridges showed alternating bands – each band magnetized with a polarity opposite the surrounding bands
Charles Darwin
theory of evolution
Panthalassa
the vast superocean that encompassed planet Earth and surrounded the supercontinent Pangaea
Divergent plate boundaries
tectonic plates move apart
transform plate boundaries
tectonic plates slide past each other
Convergent plate boundaries
tectonic plates move towards each other
Oceanic ridges
mountain ranges that have developed underwater. At the divergent plate boundary, the seafloor stretches along with the mid-ocean range
Oceanic rises
sections of the mid-ocean ridge that spread out quickly and have a gentle slope
Oceanic-continental convergence
When oceanic crust collides with a continent
Oceanic-oceanic convergence
two oceanic plates converge or collide
Continental-continental convergence
two continental plates move towards each other
Wilson cycle
model that describes the opening and closing of ocean basins and the subduction and divergence of tectonic plates during the assembly and disassembly of supercontinents
Bathymetry
the study of the “beds” or “floors” of water bodies, including the ocean, rivers, streams, and lakes
Fathom
The unit of depth in the ocean for countries using the Imperial system of units
Sounding (depth sounding)
is measuring the depth of a body of water
Echo sounder
device for determining the depth of the seabed or detecting objects in water by measuring the time taken for sound echoes to return to the listener
Multibeam echo sounder
type of active sonar system used to map the seafloor and detect objects in the water column or along the seafloor
Seismic reflection profile
can be used to reconstruct uplift and regional topographic evolution
Continental shelf
the area of seabed around a large landmass where the sea is relatively shallow compared with the open ocean. The continental shelf is geologically part of the continental crust
Shelf break
underwater edge of a continental shelf, where it begins a rapid slope to the deep ocean floor
Continental slope
the slope between the outer edge of the continental shelf and the deep ocean floor
Submarine canyon
steep-sided valley cut into the seabed of the continental slope, sometimes extending well onto the continental shelf, having nearly vertical walls, and occasionally having canyon wall heights of up to 5 km, from canyon floor to canyon rim
Turbidity current
a rapid, downhill flow of water caused by increased density due to high amounts of sediment
Continental rise
a low-relief zone of accumulated sediments that lies between the continental slope and the abyssal plain. It is a major part of the continental margin
Deep-sea fan
underwater deltas, and submarine fans, are underwater geological structures associated with large-scale sediment deposition and formed by turbidity currents
Deep-ocean trench
prominent, long, narrow topographic depressions of the ocean floor.
Abyssal plains
underwater plain on the deep ocean floor, usually found at depths between 3,000 and 6,000 metres. Lying generally between the foot of a continental rise and a mid-ocean ridge
Abyssal hills
small hill that rises from the floor of an abyssal plain. They are the most abundant geomorphic structures on Earth
Seamounts
an underwater mountain with steep sides rising from the seafloor
Pacific Ring of Fire
string of volcanoes and sites of seismic activity, or earthquakes, around the edges of the Pacific Ocean
Hydrothermal vents
fissures on the seabed from which geothermally heated water discharges
continental margins
the region of transition from the land to the deep seafloor, i.e. between continental and oceanic crust
deep-ocean basins
This includes parts of the oceans where deep water prevails
submarine canyons
any of a class of narrow steep-sided valleys that cut into continental slopes and continental rises of the oceans
Active continental margins
tend to have narrow continental shelves, active
Passive continental margins
continental margins that are not tectonically active
white smokers
chimneys formed from deposits of barium, calcium, and silicon, which are white
black smokers
chimneys formed from deposits of iron sulfide, which is black
warm-water vents
naturally forming structures found in the ocean
