1. Weathering & Erosion Vocabulary
Shaping the World We Live In
By Stacie Smith 2005 Revised by C.Hundley

2. Weathering & Erosion Vocabulary
Weathering -surface processes that works to break down rock.
Exfoliation
Frost Wedging
Enchanted Rock

3. Weathering & Erosion Vocabulary
Mechanical weathering-occurs when rocks are broken apart by physical processes. The overall chemical makeup of the rocks stays the same.

4. Weathering & Erosion Vocabulary
Chemical weathering- occurs when chemical reactions dissolve the minerals in rocks or changes them into different minerals. This changes the chemical composition of the rock, which can weaken the rock.

5. Weathering & Erosion Vocabulary
Carbonic acid – a weak acid formed when water mixes with carbon dioxide from the air – weathers such rocks as limestone to form caves.
Moister in caves combines with carbon dioxide to form a carbonic acid that dissolves limestone
Limestone – contains remnants of dead organisms

6. Weathering & Erosion Vocabulary
Oxidation – a chemical reaction which occurs when metallic materials are exposed to oxygen and water over a long period of time.
Photograph of rust-stained outcrops produced by oxidation weathering of iron-rich rock near Trout River, western Newfoundland
Iron rich soil

7. Weathering & Erosion Vocabulary
Soil – mixture of weathered rock, decayed organic matter, mineral fragments, water, and air that can take thousands of years to develop

8. Weathering & Erosion Vocabulary
Terracing – farming method used to reduce erosion on steep slopes.

9. Weathering & Erosion Vocabulary
No-till farming- a farming method which provides cover for the soil year-round, thus reducing water runoff and slowing soil erosion
"At the time that we were conventionally tilling, we were losing over nine tons of soil to the acre. After going to no-till, we reduced our soil loss to less than five tons”

10. Weathering & Erosion Vocabulary
Erosion- process in which surface materials are worn away and transported from one place to another by agents such as gravity, glaciers, wind and water.

11. Weathering & Erosion Vocabulary
Deposition – dropping of sediments (rock, sand, etc) when the wind, water, glacier, etc. loses its energy and can no longer carry the load.
Rock fall deposition, Yosemite National Park, California-On July 11, 1996, at 6:52 p.m.), two large rock blocks, with a combined volume of between 23,000 and 38,000 m3 broke away from Glacier Point. The rock disintegrated when it landed, creating an air blast that was so powerful that it flattened as many as 2,000 trees in the area. Dust from the pulverized rock blocked out the sun
Photograph by Edwin Harp

12. Weathering & Erosion Vocabulary
Abrasion- a type of erosion that occurs when windblown sediments strike rock, polishing and pitting the surface.
Water can carry abrasive rocks

13. Weathering & Erosion Vocabulary
Runoff- any rainwater that does not soak into the ground or evaporate but flows over earth’s surface; generally flows into streams and has the ability to erode and carry sediments.

14. Weathering & Erosion
River system – the network of groundwater and streams that come together to form a river .
Mississippi River drainage basin is the largest in the United States

15. Weathering & Erosion Stages of stream development
Young Stream flows swiftly through a steep valley
Erodes the streams bottom faster than the sides
Mature stream flows more smoothly
Erodes more on its sides
Curves form called meanders and flood plains

16. Weathering & Erosion Stage of stream development
Old stream flows slowly through a floodplain it has carved
Flat valley floor called a floodplain

17. Weathering & Erosion
Flooding is when too much water enters a river system, it over flows its banks.
Dams built to control the flow of water downstream
Levees mounds of earth built along the sides of the river to prevent flooding

18. Weathering & Erosion Vocabulary
Groundwater-water that soaks into the ground and collects in pores and empty spaces and is an important source of drinking water.

19. Weathering & Erosion Vocabulary
Permeable – describes soil and rock with connecting pores through which water can flow (example sandstone)

20. Weathering & Erosion Vocabulary
Aquifer – a layer of permeable rock that lets water move freely (Austin example: Edwards Aquifer)

21. Weathering & Erosion Vocabulary
Water table – the upper surface of the zone of saturation; drops during a drought

22. The Dust Bowl 1930s Lasted for a decade
Caused floods due to lack of vegetation
Families moved
No food
No money (farms useless)
Dust Storms
Lack of agriculture
Farmers learned something from the events of the dust bowl

23. Weathering & Erosion Concept Map
Types of Weathering
Chemical
Mechanical
Caused by
Caused by
Growing plants
Carbonic Acid
Expanding ice
Oxidation
Burrowing animals
Plant acids

24. Resources http://www.ptsi.net/user/museum/dustbowl.html