Oceanography chpt 1-4
Challenger
expedition in 1872-1876 is considered the first major oceanographic expedition
Alfred Wegener
first person to advance the idea of mobile continents or continental drift
found along subduction zones
oceanic trenches, active earthquake zones, island arc systems
Transform faulting
produces shallow but often strong earthquakes
Turbidity currents
underwater avalanche of muddy water mixed with rocks and other debris
Wilson cycle
uses plate tectonic processes to show the distinctive life cycle of ocean basin
Seafloor spreading generally progresses at a rate of approximately
1 to 10 cm/year
2 most common chemical compounds in biogenous sediment
Calcium carbonate (CaCo3) and Silica (Sio2)
2 major types of microscopic planktonic organisms that produce siliscious ooze
Diatoms and Radiolarians
BIogenous
Fine and coarse sediments derived from the hard parts of organisms
Harry Hess
came up with the idea of sea floor spreading
Convection cells
circular movements of rock material in the mantle
Barrier reef stage
circular reefs separated from the landmass by a well- developed lagoon
Guyots
Volcano that is flat on top
Viscocity
a measure of a substance's resistance to flow
Frederick Vine
discovered the unrelated pattern of magnetic sea floor strips with the process of sea floor spreading to explain the symmetric magnetic stripes on the sea floor
Magellan
ed voyage that first circumnavigated the globe
Passive Margins
embedded with the interior of lithospheric plates and are therefore not close to any plate boundary
Isostacy
equilibrium state which causes continental crust to float higher than oceanic crust, explaining topographic variability of the Earth's surface (e.g., ocean basins)
seamonts
an individual volcanic peak extending 1000 meters above surrounding floor
Hot spots
areas of intense volcanic activity that remain in more of less the same location over long periods of geologic time and are UNRELATED to plate boundaries
Active margins
associated w/ lithospheric boundaries and are marked by high degree of tectonic activity
average depth of the world's oceans is approximately
3,682 meters (12,080 feet)
East africa rift valleys, Red sea
DIvergent continental- continental geographic example
origin of Earth's oceans
The water that fills our oceans was mostly derived from outgassing, with a minor component coming from ice comets
San andreas fault
Transform continental geographic example
end result of the closing of an ocean basin
continent-continent collision
Himalyaya mountains
convergent continental- continental geographic example
Andes mountains, Chile trench
convergent oceanic- continental geographic example
Mariana Trench
convergent oceanic- oceanic geographic example
Deep ocean basins
deep water areas far from land
pelagic
deep water deposits
Calciate Compensation Depth (CCD)
depth at which the dissolution of carbonate equals the rate of carbonate supply
Hydrogenous sediment
derived from dissolved material in water
Cosmogenouse sediment
derived from extraterrestrial sources
Lithogenous/ terrigenous sediment
derived from preexisting rock material from erosion
Biogenous sediment
derived from the remains of hard parts of once-living organisms
Fringing Reef
develop along the margin of a landmass where temp, salinity and turbidity (cloudiness) of the water are suitable for reef-building corals
Bathymetry
measurement of ocean depths
Altimetry
measures sea floor features based on gravitational bulges in the sea surface
submarine canyons
narrow but deep valleys that are V-shaped and overhang walls
Atoll stage
ring shaped coral reef growing upward from a submerged volcanic peak.
Continental margins
shallow water areas close to continents
Neritic
shallow water deposits
Seismic moment magnitude
the energy released to create very long-period seismic waves
Isostacy
the equilibrium of the earth's crust, a condition in which the forces tending to elevate balance those tending to depress