Transcript The Structure of Hydrosphere

Structure of the Hydrosphere
The Structure of Hydrosphere
 Oceans—96.5% of water
found here
 Fresh water—3.5% of
water found here
 Fresh water distribution:
 Ice:
1.762%
 Groundwater: 1.7%
 Surface Fresh Water:
0.014%
 Atmosphere and soil:
0.002%
Understanding Where Your Water Is Located—
Fresh Water
What features house water as ice?
 Icebergs: a large piece of freshwater ice floating in open waters
 Glaciers: any large mass of ice that moves slowly over land
 *permanent snow areas also “house” water as ice
 What features house water as a liquid?
 Rivers/ Streams
 Lakes
 Ponds
 Wetlands: An area of land that is saturated with water for the
majority of the year. (Ex. Swamp, Marsh, etc.)
 Aquifer: An area of rock underground that holds freshwater.
Thinking Question:
- Which features, ice or liquid, house the most freshwater on planet earth?
Fresh Water Locations—Surface Water
Rivers/Streams
 How does water get to rivers and streams?
Runoff from watersheds and river basins.
 What is the difference between a watershed and a river basin?
 Both terms describe land that drains into a river, stream or lake

River Basin: the area of land that is drained by a river and its tributaries.
Watershed: the land area that supplies water to a river system.
* There can be multiple watersheds within a river basin.
What do the U.S river basins look like?
1.
2.
3.
What geographic features divide our country into different river basins?
Where do all of the river basins ultimately drain their water?
Which river basin supplies the water for the local rivers in southeast North
Carolina?
What are the two types of streams?
Meandering Stream: Streams that have channels with many curves.
Braided Stream: Streams with many bars and islands separated by
channels.
Activity: To the best of your ability; draw a meandering and braided
stream in your notes. (I will demonstrate on the board)
What is stream erosion?
Stream erosion: The movement of rock and sediment to other places
through the flow of a stream.
- Bed Load: Bottom- Sand and Gravel.
- Suspended Load: Middle- Silt and Clay
- Dissolved Load: Top- Dissolved Minerals
What is the result of stream erosion?
1.
1.
Canyon Formation: Over thousands of years stream and river erosion
can cut into the earth to form caynons.
Ex. Colorado river and the Grand Canyon.
Continued
2. Alluvial Fans: Streams deposit sediment onto a flat area of land.
Continued
3. Delta: Streams deposit sediment into a body of water.
Fresh Water Locations—Surface Water
Lakes
How are lakes formed?
- 1. Glaciers: Glaciers scoured out depressions that over time fill in with runoff water.
Natural Lakes:
- Ex. Great Lakes- They hold 18 percent of Earth’s freshwater.
- http://upload.wikimedia.org/wikipedia/commons/c/c3/Great_Lakes_from_space
.jpg
2. Crustal Movement: The Earth’s crust can move and create depressions that fill in with
water.
3. Volcanic Eruption: After a volcanic eruption the top of the volcano can fill with water.
Caldera: http://www.gvb-csic.es/CCDB/iamgenes/KatmaiCaldera.jpg
4. Formation of a dam:
Human-made lake
Ex. Hoover dam
http://philip.greenspun.com/images/pcd2882/hoover-dam-aerial-91.4.jpg
Thought Question: Why might a dam and reservoir be useful in a dry area?
Answer: The reservoir could store water for drinking and irrigation.
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-
What is eutrophication?
Eutrophication: An increase in nutrients and organism that is a normal
part of a lake’s life.
Thought Question:
How could building a dam lead to an increase in eutrophication in a
lake?
Answer: When a dam is constructed and forms a reservoir, sediment can
collect behind the dam and quickly fill in the reservoir.
Other Surface Waters
 What is a wetland?
 An area where the water table is at, near or above the land
surface long enough during the year to support adapted plant
growth
 What are the types of wetlands?
 Swamps, bogs, and marshes
Swamp: a wetland dominated by trees
 http://dnr.state.il.us/wetlands/images/swamp21.jpg
 Bogs: a wetland dominated by peat moss
 http://www.travelblog.org/Photos/223909
 Marshes: a wetland dominated by grasses
 http://water.epa.gov/type/wetlands/images/marsh.jpg

Why are wetland important?
 They trap sediment:
 The trapped sediment cannot enter into lakes and streams.
This keeps streams and lakes clear.
 They use a lot of excess nutrients:
 Wetlands near lakes and streams use these nutrients for their
plant growth. Decreasing eutrophication.
Fresh Water Locations--Groundwater
 What is groundwater?
 The water found in cracks and pores in sand, gravel and rocks
below the earth’s surface
 What is an aquifer?
 A porous rock layer underground that is a reservoir for water
 http://geoscape.nrcan.gc.ca/ottawa/images/biggroundwater.j
pg