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Modern Methods for Measuring the Bathymetry of the Ocean floor:
- Echo sounding and Swath Mapping - a method using powerful sound pulses.
- Satellite Altimetry - Satellites can measure the height of the ocean very accurately.
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the mid-ocean ridges are essentially a long continuous under water ____.
volcano
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shallow and relatively flat region overlying continental crust.
Continental shelf
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Transition region between continental and oceanic crust is...
Continental Slope
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Thick prism of sediment deposited at base of Continental slope
Continental rise
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Broad flat plain covered with sediment, overlying rugged ocean floor.
Abyssal Plain
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Active margins are located near the edge of _____ plates. Active margins are the site of ______ and _____ activity.
converging. volcanic, earthquake
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_____ can only occur where slopes are relatively steep. Upon reaching the flat Abyssal floor _(answer above)_ ____ and ____ their sediment.
Turbidity currents, TB, weaken and deposit
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_______ are volcanic projections from the ocean floor that do not rise ______. flat topped seamounts eroded by wave action are called ______.
Seamounts; above sea level; guyots
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Symmetric ripples are formed by.....
waves
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Asymmetric currents are currents formed by.....
currents
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Classification of Sediment and its source
Terrigenous -
Biogenous -
Hydrogenous -
Cosmogenous -
- Terri- Erosion of land, volcanic eruptions, blwon dust
- Bio- Organic; acummulation of hard parts of some marine organisms
- Hydro- Precipitation of dissolved minerals from water, often by bacteria
- Cosmogenous - dust from space, meteorite debris
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What pathways do sediments travel to reach the ocean?
- Fluvial Inputs - Rivers dischange Sediment into the Ocean
- Aeolian inputs - winds carry sediments from the continents into the ocea
- Biological inputs - marine organisms die and sink to the bottom
- Authigenic inputs - sediments that are formed in the oceans. Mainly metal rich materials near hydrothermal vents
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Most deep sea clays derived from _________ transport.
eolian
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_______ can transport terrigenous sediment down the continental slope.
Turbidity currents
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Any sediment that is > 30% biologically- derived materia is called a ....?
"ooze"
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Calcium Carbonate solubility increases with ______ and _____.
increasing pressure; decreasing temperature
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The depth below which carbonate sediments will not accumulate is called...? and why doesn't "marine snow" read.
- Carbonate Compensation Depth (CCD)
- Below CCB, water holds more CO2, which results in more carbonic acid, which dissolves CaCO3 faster.
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What does Calcium Carbonate Content tell us?
- 1) North Pacific is generally deeper than North Atlantic
- 2) Mid-Ocean ridges are shallower than abyssal plain.
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Silica preservation mainly reflects _____?
biological productivity
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Hydrogenous sediments _____ directly from seawater.
What are most common hydrogenous sediments?
- precipitate
- manganese nodules, include evaporites and oolites
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Biogenic Sediment are? 3 caterogies
Carbonate Ooze, siliceous ooze and biogenic material.
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