How the sea got its salt and nutrients in the ocean

what are the 4 principle rock forming minerals?

oxygen, silicon, aluminium and iron

what are 3 of the least abundant metals in earths crust?

gold, platinum and rhenium

what are the most abundant elements in seawater?

oxygen and hydrogen

is chlorine more abundant in the sea or crust?

chlorine

is sodium more abundant in the crust or seawater?

seawater

what is the most abundant elements in rivers?

carbon in the form of bicarbonate then calcium and silicon

how is salinity nearly always calculated?

conductivity measurements

Is there more variation in salinity in the lower depth or higher depth of the ocean?

more variation in salinity

why is there lower salinity nearer the equator?

more precipitation and evaporation

what does major ions showing conservative behaviour mean?

the ratio to salinity of major ions stays the same throughout the area

which major ions show smaller variation?

calcium ions as are utlised in surface water and re-dissolve at depth

what does mass balance mean?

requires that the products must equal the reactant we started with

what is the principle source of elements in seawater?

rivers

what are the other examples of sources of elements to seawater?

volcanic gases, dust, hydrothermal vent fluids, sediment pore waters

what is the equation for river flux?

water flux x concentration in element in river water

what is mean ocean residence time?

the time between the element entering the ocean and being removed from the ocean

what is the formula for mean ocean residence time?

amount in ocean/ flux out of ocean

what elements are all organisms made up of?

H, C, N, O and P

what ratio of carbon to nitrogen to phosphate do most marine systems have?

106:16:1

why are nutrients considered limitations?

abundance of nutrients determines how much primary production can take place

what is nitrogen used for in organisms?

amino acids, RNA, and enzymes

what is phosphorous used for in organisms?

ATP, phospholipids

what is silicon used for in organisms?

diatoms, radiolaria

what are metals used for in organisms?

enzyme systems

why aren’t all organisms nitrogen fixers?

more energy expensive

why is limiting the amount of primary productivity significant?

will impact the whole carbon cycle

what is the formula for photosynthesis?

carbon dioxide + water = glucose + oxygen

what led to our atmosphere being oxygenated?

evolution of marine photosynthetic organism early in earths history in the great oxidation event

why are phytoplankton important in regulating climate change?

lead to the removal of atmospheric CO2 and transfer of carbon to deep water and sediments within the carbon cycle

where does photosynthesis primarily take place in the ocean?

upper surface

how do phytoplankton end up in the deep ocean?

phytoplankton are eaten by zooplankton, consumed and excreted, then die which eventually leads to them sinking from the photic zone into the deep ocean

why do not all plankton end up in the deep ocean?

some also decomposes turning into dissolved organic carbon

what is the large proportion of organic material made of in the surface ocean?

soft tissue

what is a large proportion of the organic material in the deep ocean made of?

skeletal material

where does chemical recycling mainly take place?

surface ocean

what are the two main classes of falling particle?

feacal pellets and marine snow

what is snow fall?

snow particles are fragile aggreagtes of organic matter that builds up and falls to the deeper ocean

when is organic material at its highest?

early spring

why does organic mater