1. Structure of the Hydrosphere
Monday, November 7, 2011

2. The Big Picture
Around the continents... Oceans cover 2/3 of Earth’s surface!
On land...Water flows in rivers and streams and fills lakes and ponds!
Even underground... Water trickles through rock to create groundwater!

3. The Hydrosphere HYDROSPHERE= the part of Earth containing water
most water in hydrosphere is liquid
salt water = about 97% (oceans)
fresh water = about 3%
frozen: ice caps, glaciers, snow, permafrost
liquid: groundwater, lakes, wetlands, rivers, atmosphere

4. Hydrosphere
All Water
Fresh Water

5. The Global Ocean Oceans cover ~71% of Earth’s surface
All ocean water is connected in a global ocean
divided by continents into four major parts:
Pacific Ocean, Atlantic Ocean, Indian Ocean, Arctic Ocean

6. The Global Ocean

7. Ocean Size The Pacific Ocean is the largest and deepest
covers 165 million square kilometers
average depth of 4,282 meters
deepest part = Marianas Trench region (about 11,033 meters deep!)

8. Ocean Size Other oceans are smaller:
2nd: Atlantic Ocean (half the volume of the Pacific!)
3rd: Indian Ocean
Smallest: Arctic Ocean (much covered by sea ice)

9. Salinity
Salinity = the concentration of salts in a liquid, such as water
ocean water tastes salty because of dissolved salts
ordinary table salt = about 85% of these salts in oceans!
salinity increases as more salts are dissolved in water
ocean water has a salinity of about 3.5%
every 100g of ocean water contains average 3.5g of dissolved salts

10. Ocean Temperature temperatures vary depending on latitude and depth
What parts of Earth receive the most sunlight and therefore more energy?

11. OceanTemperatures
The EQUATOR receives more direct sunlight and therefore receives more energy from the sun
Surface temps can reach 25°C
Near the poles temperatures tend to be near freezing
below a depth of 300m, water temperatures drop quickly as the sun no longer warms it
In the deepest parts of the oceans, temps range from 1°C to 4°C

12. Freshwater Resources
Most of Earth’s fresh water is frozen in polar ice caps
covers almost all of Antarctica
covers most of the Arctic Ocean, near the North Pole
Glacier = a mass of ice and snow that moves slowly over Earth’s surface
contain large amounts of frozen water

13. Fresh Water Groundwater = water located below Earth’s surface
nearly 1/3 Earths fresh water
forms when surface water moves down through soils and sediment to collect in spaces between underground rock particles
aquifer = a rock layer that stores water and allows water to flow through it
drinking water and irrigation water often come from aquifers

14. Groundwater

15. Wetlands and Land Water
Most of Earth’s surface water is located in rivers, streams, lakes and wetlands
wetlands = land areas that remain wet for all or part of the year
act as sponges, collecting and holding rainwater to prevent flooding
also filter pollutants and sediment out of water
can improve the quality of water that will eventually become drinking water

16. Watersheds
watershed = an area of land where precipitation collects and then drains into a single collection place, often a lake or an ocean
sometimes called drainage basins, river basins
main function = move water from higher to lower elevations

17. Other Surface Waters
river = a large, flowing stream of water fed by other small streams
tributaries = smaller streams that feed rivers
lake = a low area of land where surface water run-off accumulates
vary in size

18. Think About it...
Why might groundwater be cleaner than surface water?