Chapter 2: Ocean Environment Flashcards
What is the earth cover for the amount of water on the surface and what is a constant amount of depth?
71% of Earths surface is covered by oceans and 84% of the ocean is 2000m in depth
What is the difference between an ocean and a marginal sea?
Name two marginal seas?
A marginal sea is enclosed and they aren’t stable like oceans. Marginal seas are effected by the continents they are by, climate, precipitation, run offs from rivers streams and they have limited exchange for currents.
Gulf of Mexico and the Mediterranean
From picture 1, name these topographic features?
Continental shelf, submarine canyon, and an Abyssal Plain
What is sea floor spreading?
Where oceanic crust moves laterally and is destroyed by subduction which forms trenches
What is continental drift?
Where continents in ocean crust lead to movements of plates ex. Pangea or Laurasia
What forms volcanoes?
Hot spots where crust is thinner so heat from the earth escapes
What is a mid ocean ridge?
Where the formation of oceanic crust is and the further away you get from the crust the older the plate is
What is a fault?
A fault is a zone where to plates interact but at different rates
What are 3 points referring that continental drift is occurring?
- Fauna that is dating with similar geologic times and the same species are occurring on different continents
- Seafloor mapping and dating where a progressive age is determined and where trenches and island chains are submerged
- Geomagnetism where polar reversal caused parallel alternating bands of magnetized rock on the sea floor, with new crust emerging at 5cm/yr
What kind of solvent, bond, and charge does water have?
What is a good solvent because of its polarity, it has covalent bonds and hydrogen bonds. Hydrogen bonds are weaker due to asymmetry of charges but covalent are stronger
What 3 things is water high in compared to other solvents?
High heat capacity (1Cal to raise 1g of water by 1˙ at 15˙), latent heat of fusion (solid to a liquid is very high), and heat of vaporization (takes a lot of heat for water to become vapour)
What cools and heats faster; land or water? And who effects who?
Land heats and cool quicker and if there is adjacent water nearby, the water directly controls the land by influencing the climate
Is water good at dissolving materials?
Yes!
What additions heat the ocean?
Latitudinal gradient of solar heating, geothermal heating, internal friction, and water vapour condensation
What losses are apparent in cooling the ocean?
Back radiation from the surface, evaporation, and convection of heat to the atmosphere
What is salinity?
What is the equation for salinity?
The number of grams of dissolved inorganic solids per 1000g of seawater, units in ppt
Sal= 1.81 x chlorinity
What controls salinity?
Addition by evaporation, sea ice formation, loss from precipitation from river run off
What is the open ocean % concentration? What is that equilivant to for every 1000g?
The open ocean is 32-38% and is equal to 32-38g per 1000g
What elements are important to seawater?
Chlorine 55%, sodium 30.6%, magnesium, sulfur, calcium, carbon (variable) are all much less
What is Forchhammers Principle?
Ratios between elements in the seawater is constantly all over the ocean, even though salinity varies. Therefore, the ocean is well mixed relative to addition or removal.
What is chlorinity? How is it measured?
g of of chlorine per L of water
It is measured by chemical titration, conductivity, and index refraction
What is water density and how does it fluctuate?
Water density is the mass/volume and is dependent on temperature
As salinity increases, so will density
If temperature decreases, density will increase
