Chapter 14: Ocean Water and Ocean Life Flashcards
The average seawater of saline and salinity?
3.5% saline
Salinity= total amount of salts dissolved in the water
Sources of Sea Salts?
1) Chemical weathering of rocks
2) Volcanic outgassing
The process that decreases salinity by adding fresh water to oceans is?
1) Precipitation
2) Runoff from land
3) Icebergs melting (only fresh)
4) Sea ice melting (only fresh)
The process that increases salinity by removing water, leaving salt behind is?
1) Evaporation
2) Formation of sea ice (freezing seawater in saline ocean)
Ocean Temp Variations: Low-latitudes?
receive more direct sunlight
- water have high temp @ surface
- rapid decrease in temp w/ depth is called thermocline
Ocean Temp Variations:
High-latitudes?
receive less direct sunlight b/c closer to the N and S poles.
Water has cooler surface temp.
NO thermocline present
What is Density?
The mass per unit volume; basically how heavy something is for its size
Two factors affecting seawater density?
1) Salinity- dissolved solids in water, the more it will be
2) Temperature- greatest influence; increase water temp causes thermal expansion and reduces density
What sea is ten times as saline as average seawater and therefore much more dense?
The Dead Sea
Ocean layering is based on what?
Water density
The three zones in ocean layering?
1) Surface Mixed Zone: sun warmed. relatively shallow
2) Transition Zone: temp fall w/ depth. Thermocline present
3) Deep Zone: sunlight never reaches. temp few degrees above freezing. high density
The three classifications of marine organisms?
1) Plankton (floaters): bacteria; makes up most earth’s biomass
2) Nekton (swimmers): sea animals capable to move independently Unable to move through breadth of ocean b/c of temp & nutrients
3) Benthos: bottom dwellers, can live in shallow to deep water
What zones are used with the Availability of Sunlight?
Photic zone- upper part that is sunlit. Eurphotic is where light is strongest
Aphotic zone- deep ocean, no sunlight
What zones are used with the Distance from the shore?
Interidal zone- land & ocean meet and overlap
Neritic zone- low tide line continental shelf out to the shelf break
Oceanic zone- beyond continental shelf
What zones are used with the Water depth?
Pelagic zone- open ocean of any depth
Benthic zone- include and sea-bottom surface
Abyssal zone- subdivision of benthic zone (food sources include hydrothremal vents)
