Transcript Ocean basins, currents, and climate change   [CO2] equilibrium at sea surface Reactions with H+ and OH- ions       Step 1: carbonic acid Step 2: carbonic.

Ocean basins, currents, and climate
change


[CO2] equilibrium at sea surface
Reactions with H+ and OH- ions






Step 1: carbonic acid
Step 2: carbonic acid to H+ and bicarbonate
Step 3: bicarbonate to H+ and carbonate ion
Carbonate + Calcium incorporated into
shells of organisms (aragonite, calcite)
Insoluble shells sink
More CO2 can dissolve into sea surface




Very small scale chemical reactions
Small scale biological processes
Aggregation to large scale
movements of carbon
Influences very large scale ocean
patterns and climate on a global
scale





What factors influence sea level?
What factors influence sea temperatures?
How do atmospheric conditions alter
currents?
How do currents influence atmospheric
conditions?
How can reliable predictions be made?
Factors influencing the volume of water in a
basin relative to shorelines:
 Size of basin
 Amount of liquid water available
 Density of water
 Gravity

Plate tectonics: components



Plate tectonics: processes




solid plates of rock over semi-fluid (hot) magma
plates can be lighter granitics or heavier basalts
Spreading where magma emerges between plates
Subduction where spreading plates are pushed under
neighboring plates
Uplift where plates collide and rise
Dynamic Equilibrium – but changing ocean sizes
over “geologic time scales”
Blue: 180 MYBP




Comets/meteorites: 0.1% water
Hydrologic cycle from continents (rivers)
Melting of ice
 glaciers
 polar ice
Thermal expansion


Evaporation to atmosphere or to space
Freezing (importance of albedo)
 “Snowball earth”
 Positive feedback, “runaway”
conditions
 Compare to negative feedback
carbonate-silicate cycle