Marine test 1 Flashcards
what is salinity?
the amount of salt in the water
how much salt per litre does oceanic water have?
35g/L
what percentage of all ocean waters contain salt concentrations of 35/L?
75%
solvent properties of water?
water has an enormous ability to dissolve substances because of its polar nature. This allows salts from the land and ocean floor to dissolve
what is heat capacity?
the ability of water to resist temperature change
heat is a measure of what?
molecular motion
water has great resistance to change, what about salt water?
same ability but less
what would happen to the molecules if the water temperature rose?
molecules would need to move faster but the hydrogen bonds resist this so it would keep seawater at a relatively constant temperature
what is the latent heat of fusion?
the heat required for either melting or forming ice
what is the latent heat of vaporization?
the heat released when water evaporates. Heat is continuously being absorbed by the oceans, but they do not get hotter.
why do oceans absorb the heat being evaporated?
This is because heat is released as the hydrogen bonds break allowing water molecules to vaporize into the atmosphere . It is much greater than that of fusion and marine animals make use of this cool down
what is density?
the mass per unit volume
what is mass measured in?
grams and volume in cubic meters (cm3) mass/volume
what happens if the density is less than 1?
it will float
what happens if the density is more than 1?
it will sink
what is the relative density of a substance?
the ratio of the density of that substance, to the density of pure water
What’s the density if the water is saltier?
the density is higher
What’s the density if the water is colder?
the density is higher
what is viscosity?
the resistance of a liquid flowing through or passing an object
what is the flow of high viscosity?
slow flow
what is the flow of low viscosity
fast flow
is water denser than air? if so how many times denser
800 times
what is buoyancy?
the ability or tendency to float
which has a greater upthrust of buoyancy? Sea water or fresh water? why?
seawater, because salt water is higher in density
what is hydrostatic pressure?
the water pressure in the waters of the oceans
what is atmospheric pressure?
the water pressure found in the air around the earth
surface=?
1 atmosphere
10m below=?
2 atmospheres
what is surface tension?
the tendency of liquid surfaces at rest to shrink in a minimum surface area as possible
why does the tendency of liquid surfaces at rest to shrink in a minimum surface area?
this is due to cohesion (sticks to itself) and adhesion (sticks to other objects)
why are the gases dissolved in the sea important?
important for respiration and photosynthesis
what are the two major gasses involved in these chemical reactions?
carbon dioxide and oxygen
how is turbulence affected in dissolved gases?
more movement of water (waves and streams), the more oxygen can dissolve
how is temperature affected in dissolved gasses?
increases temperatures cause a decrease in the ability to dissolve gas
how is salinity affected by dissolved gasses?
lower salinity, greater amount of dissolved gases
how is pressure affected in dissolved gasses?
deep water which has a high pressure holds more gas than shallow water
what is the photic zone?
is the zone or depth to which light penetrates in the seas and is the zone where sea plants live.
what happens to depth if the wavelength is shorter
greater depth
how long is the greatest penetration?
420nm wavelength
red is what length of the wavelength
the longest
violet is what length of the wavelength
the shortest
oceans have what two types of water? describe
blue water: surface water contains little minerals so has little plant life
green waters: contains large concentrations of ions, causes abundant plant growth which attracts a number of animals.
sounds travels how many times faster in water than in air?
4 times faster, so vibrations are more easily detected.
