Question | Answer |
Currents/Ocean Water Movement | Marine Environments |
deep-sea currents, cold and salty | density contrast currents |
Antarctic Bottom Water | AABW |
very cold dense water around Antarctica sinks | AABW |
flows along ocean bottoms northward | AABW |
North Atlantic Deep Water | NADW |
cold dense water from the Arctic Ocean | NADW |
sinks and flows southward above the AABW | NADW |
cool dense water from Mediterranean and Antarctica | intermediate waters |
sinks and flows above NADW | intermediate waters |
wind controlled | upwelling zones |
cool water moves to the surface | upwelling zones |
replaces water pulled from basin margins by gyres | upwelling zones |
water often rich in nutrients (Si, P, N) | upwelling zones |
wind driven | Surface Waves |
circular particle motion at sea | Surface Waves |
near-shore/shallow depths | Surface Waves |
elliptical particle motion | Surface Waves |
wave base/bottom = back and forth particle motion | Surface Waves |
waves steepen and break at very shallow depths | Surface Waves |
abrasion, concussion | surf zone |
particle rounding | surf zone |
strong erosion, winnowing | Surface Waves |
sediment size sorting, often cross-bedded | Surface Waves |
water/sediment motion parallel to the shore | longshore drift/longshore currents |
wave motion oblique to the shoreline | longshore drift/longshore currents |
rotation of the Earth beneath tidal bulges | tides |
result from gravitational attraction of sun and moon | tidal bulges |
. ~ 2 tidal cycles every 24 hours | tides |
zone effected by tidal water changes | intertidal zone |
large changes in environmental conditions | intertidal zone |
temperature changes | environmental conditions |
high particle concentration in the water | environmental conditions |
usually high a energy environment | intertidal zone |
often fringed by marshes | intertidal zone |
formed by low-growing plants | marshes |
low energy zones of mud accumulation | marshes |
usually dry | supratidal zone |
exceptionally high tides cause flooding | supratidal zone |
never exposed to air | subtidal zone |
zone of light penetration through ocean water | Photic Zone |
100-200 meters penetration | Photic Zone |
200 m is the ~ shelf break depth in many areas | Photic Zone |
life zone of the phytoplankton (microscopic plants) | zone of photosynthesis |
marine (flooded) extension of a continent | Continental Shelf |
represents 10% of the worlds continental area | Continental Shelf |
end of the Shelf is marked by the Shelf Break | Continental Shelf |
sediment collects here, builds up here | Continental Shelf |
majority of the Earth's sedimentary strata formed here | Continental Shelf |
zone of transition between continental and oceanic crust | Continental Slope |
deepening water, erosion/deposition by turbidity currents | Continental Slope |
cut by submarine canyons | Continental Slope |
zone of terrigenous sediment accumulation | Continental Rise |
~3-6 kilometers deep | Abyssal plain |
barrier islands | Ocean Margins |
parallel to shoreline | barrier islands |
sand build-up by wind and erosion | barrier islands |
lagoons or bays | Ocean Margins |
behind and protected by barrier islands | lagoons or bays |
shallow, quiet, often warm water | lagoons or bays |
often fringed by marshes in intertidal zone | lagoons or bays |
plant accumulations may form peat | lagoons or bays |
epicontinental sea | Ocean Margins |
semi-isolated | epicontinental sea |
broad flooding of low elevation continental areas | epicontinental sea |
example: Hudson Bay in Canada | epicontinental sea |
floaters | Planktonic |
phytoplankton living in the photic zone | plants |
diatoms | phytoplankton |
dinoflagellates | phytoplankton |
calcareous nannoplankton | phytoplankton |
zooplankton which eat other plankton | animals |
single cell Protozoans; forams, radiolarians | zooplankton |
planktonic Foraminifera- CaCO3 | forams |
SiO2 | radiolarians |
primarily swimmers like fish; multicellular organisms | nektonic organisms |
primarily bottom dwellers; multicellular organisms | benthonic organisms |
burrowing organisms | benthonic organisms |
boring organisms | benthonic organisms |
grazing organisms | benthonic organisms |
draw food from the water | suspension feeders |
consume sediment, use organics as food | deposit feeders |
amoeba-like organisms - benthic forams | pseudopod feeders |
fall in several categories | bacteria |
dictates the type of shell which can easily be built | temperature |
CaCO3 | warm water |
calcareous nannoplankton | warm water |
reefs | warm water |
forams | warm water |
SiO2 | cold water |
diatoms | cold water |
radiolarians | cold water |
generally ranges from 30-40 parts per thousand salts | salinity |
low salinity | brackish water |
ocean margin bays and lagoons | brackish water |
fresh water dilution from rivers | brackish water |
high salinity | hypersaline water |
ocean margin bays and lagoons | hypersaline water |
salt concentration by evaporation | hypersaline water |