The document summarizes key aspects of physical oceanography. It discusses the composition of seawater, properties like salinity, temperature, pressure and density. It also describes major ocean basins, currents that circulate water globally, and ocean motions including waves and tides. Overall, the document provides a broad overview of physical characteristics and processes within Earth's oceans.

1. Hydrosphere
Blastoise used surf!

2. Oceanography
• Composite science that draws methods and
knowledge from biology, chemistry, physics, and
geology to study all aspects of our world’s
oceans.

3. Some Boring Numbers
• The area of the earth is 510M km2
• The area of the oceans and marginal seas is
360M km2
• The area of the continents is 150M km2
• The northern hemisphere is 61% water and 39%
land
• The southern hemisphere is 81% water and
19% land

6. The World’s Oceans
• Pacific
▫ Largest; Bigger than the Atlantic plus the Indian
Ocean.
▫ Slightly more than ½ of the world’s waters
• Atlantic
▫ Center of a nearly parallel continental margin
▫ Shallowest
• Indian
▫ Smallest
▫ Southern Waters

8. Comparison of Oceans and
Continents
• Volume – all land is just one eighteenth that of
the oceans
• Relative levels (elevation, depth)
▫ The average elevation above sea levels is 840
meters
▫ The average depth of the ocean is 3800 meters

9. Physical Properties of Sea Water
• Composition
• Salinity
• Light Penetration Zones
• Temperature
• Pressure
• Density

10. Composition

11. Salinity
• Salt content in water
• Average for:
▫ Salt Water
 30 – 35 ppt
▫ Brackish Water
 0.5 – 18 ppt
▫ Fresh Water
 < 0.5 ppt

12. Light Penetration Zones

13. Temperature
• Temperature layers
• The effect of
salinity and pressure is the
same for every
temperature

14. Water Pressure
• Pressure – a force that acts on an area
• Pressure increases by one atmosphere every 10
meters in depth in the water column
• One atmosphere is 14.7 pounds per square inch

15. Density
• The average sea water density is 1027 kg/m3
• There are 2 main factors that make more or less
dense than 1027 kg/m3
• These are temperature and salinity
• Cold water is denser than warm water
• Saltier water is denser than fresh water
• Temperature has a greater effect on density than
salinity

17. Motions of the oceans
• Currents
• Waves
• Tides

18. Currents
• Ocean currents move water continuously along
specific pathways, often across vast distances.
• This happens both on the surface and in the
deep ocean.
• Currents are driven by the wind across the
ocean’s surface.

19. Current Facts
• Persistent, dominantly horizontal flow
• Heat exchange between the poles and the
equator
• Surface currents are powered by the wind
• Gyres – circular movement of a large ocean
current
• Transports organisms, nutrients and pollution
across vast distances

20. Tides
• Is the rise and fall of sea levels caused by the
combined effects of the gravitational forces
exerted by the moon and the sun and the
rotation of the earth.

22. Waves
• Factors that affect the waves
▫ Speed of the wind
▫ Time of the wind
▫ Distance of the wind (fetch)
• Fetch
▫ the length of water over which a given wind has
blown