The document provides an overview of key facts about oceans: - Oceans cover 70.8% of the Earth's surface and have an average depth of 4,000 meters. The deepest point is in the Marianas Trench at 11,000 meters. - The Pacific Ocean is the largest, covering 30.5% of the Earth's surface. Other major oceans are the Atlantic, Indian, and Southern oceans. - Water has unique properties like existing in solid, liquid, and gas forms and having high heat capacity, which influence Earth's climate and ability to support life. - Ocean depths are divided into zones like the continental shelf, pelagic zone, and abyssal zone that have different environmental conditions

1. Oceans:
A Brief Intro
Dr. Mark A. McGinley
Honors College and Department of
Biological Sciences
Texas Tech University

2. Fun Facts
• 71 % of Earth’s surface covered by oceans
– 80 % of Southern Hemisphere
– 60 % of Northern Hemisphere
• Ocean average depth- 4,000 meters
• Maximum depth 11,000- meters (approx 7
miles) in Marianas Trench
• Below 1000 meters the ocean is dark and cold
– Largely lifeless

3. Oceans of the World

4. Table 1: Surface area of our planet covered by oceans, water and land.
Percent of Earth's Area (Square Area (Square
Surface
Total Surface Area Kilometers) Miles)
Earth's Surface Area 29.2% 148,940,000 57,491,000
Covered by Land
Earth's Surface Area 70.8% 361,132,000 139,397,000
Covered by Water
Earth's Surface Area 65.7% 335,258,000 129,444,000
Covered by Ocean
Pacific Ocean 30.5% 155,557,000 60,045,000
Atlantic Ocean 15.1% 76,762,000 29,630,000
Indian Ocean 13.4% 68,556,000 26,463,000
Southern Ocean 4.0% 20,327,000 7,846,000
Arctic Ocean 2.8% 14,056,000 5,426,000

5. Pacific Ocean

8. Important Properties of Water
Water is unique in that it is the only
natural substance that is found in all
three physical states- liquid, solid, and
gas—at the temperatures normally
found on Earth.
- Hydrologic Cycle
http://ga.water.usgs.gov/edu/waterproperties.html

9. Important Properties of Water
Water is unusual in that the solid form,
ice, is less dense than the liquid form.
Thus, ice floats.

10. Important Properties of Water
Water is called the “universal solvent"
because it dissolves more substances
than any other liquid.
-wherever water goes, either
through the ground or through our
bodies, it takes along valuable
chemicals, minerals, and nutrients.
- most important biochemical
reactions take place among chemicals
dissolved in water in cells

11. Important Properties of Water
Water molecules are highly cohesive
-very sticky. Surface Tension.

12. Important Properties of Water
• Water has a high specific heat index
– it absorbs a lot of heat before it begins to get hot.
• This is why water is valuable to industries and in
your car's radiator as a coolant.
• The high specific heat index of water also helps
regulate the rate at which air changes
temperature
– why the temperature change between seasons is
gradual rather than sudden, especially near the
oceans.

13. Patterns of Temperature Variation
33o N 34o N

14. Important Properties of Water
• The relative high density of water allows
sound to move through it long distances
– ask a whale!
• In sea water at 30°C, sound has a velocity of
1,545 meters per second (about 3,500 miles
per hour).

15. Water
• Often hear references to “fresh water” and
“sea water”
• Fresh water has no, or very low concentration
of, substances dissolved in it
• Sea water (sometimes referred to as “salt
water) has higher concentration of dissolved
substances

16. Salinity
• Salinity
– Measures the amount of dissolved inorganic solids
in seawater
• Expressed as parts per thousand (ppt) or percent (%)

17. Sea Water
• Major elements (> 100 • Minor elements (< 100
ppm) ppm)
– Chlorine – Bromine
– Sodium – Carbon
– Magnesium – Strontium
– Sulfur – Borom
– Calcium – Silicon
– Potassium – Flourine

18. Structure of the Ocean
• The ocean is not just a giant swimming pool!!

19. Cross Section of Ocean Basins

20. Continental Shelf

21. Continental Shelf
• The average width of continental shelves is
about 80 km (50 mi).
• The depth of the shelf also varies, but is
generally limited to water shallower than
150 m (490 ft).
• The slope of the shelf is usually quite low, on
the order of 0.5°; vertical relief is also
minimal, at less than 20 m (66 ft).

22. Global Continental Shelf

23. Importance of Depth
Light Penetration

24. Importance of Depth
Temperature

31. Pelagic Zone

32. Abyssal Pelagic Zone

36. Hydrothermal Vents