Trace elements dissolved in the ocean Flashcards
What are the key sources of dissolved materials?
•Fluvial (with river water)
• Atmospheric
• Hydrothermal
What are the components of seawater?
• Major ions
• Minor constituents
• Trace elements
What are examples of major ions components in seawater?
Alkali earths and halides (especially Sodium Chloride (NaCl), bicarbonate and calcium
What are some minor constituents in seawater?
• Gases — e.g. N2, O2, CO2
• Nutrients — e.g. NO3-, PO42-, SiO2
What are trace elements?
Everything else present in the sea but not in high concentration
What is true of elements entering the ocean from rivers?
• Some elements dissolved in the water may also remain in estuaries — e.g. phosphorous may remain attached to particulate matter
• Much of the particulate load (up to 90%) is trapped in estuaries and coastal areas
What is the total dissolved load entering the ocean from rivers?
3.7 x 10^15g yr^-1
What is the total particulate load entering oceans from rivers?
15.5 x 10^15 g^yr-1
What are the origins of fluvial inputs?
Natural or anthropogenic(and pollutant)
What are the types of elements that can enter the oceans from the atmosphere?
Dry (particles) or wet (rainfall) disposition
What is an example of natural origin of elements from the atmosphere?
Windblown from mountains
What is an example of anthropogenic origin of elements from the atmosphere?
From power station chimney
What is try of elements entering oceans from the atmosphere?
• They may be in particulate or dissolved form — i.e. particles may subsequently dissolve
• Inputs will vary regionally
What is hydrothermal flux?
Hydrothermal flux is related to the mass flux of seawater by the water temperature anomaly and by the specific heat of seawater
What is true of hydrothermal fluxes to the ocean?
• Scale of inputs not well known for some may exceed riverine inputs — e.g. Li, Fe and Mn
• Some elements may precipitate very quickly on entering the seawater — e.g. iron and manganese oxides/black smoker chimneys
