Breaking Down the RocksWeathering and erosion

Eric AngatTeacher

Karst topography is any region where the terrain, commonly limestone, has been dissolved by the physical and chemical weathering of the bedrock.

1. How do caves and sinkholes form?

Karst topography form when underground limestone dissolve.

http://www.youtube.com/watch?v=HYV6gBssMFs

Cave formation

http://www.youtube.com/watch?v=67Y0pz9R32g

Sinkholes in Florida

A map of the United States showing regions displaying or having active karst topography.

2. Which part of the United States has the most Karst topography?

Florida

Cause of Florida sinkhole tragedy: Human activity or revenge of the karst?

One of the most heavily developed states is also one of the most geologically hazardous – two facts that are not mutually exclusive in creating dangerous sinkholes.By Patrik Jonsson, Staff writer / March 2, 2013

The Great Guatemalan SinkholeOn Sunday, May 30, 2010, an enormous hole, 60 feet wide and 30 stories deep, opened up in the middle of Guatemala City, swallowing a three-story building, a home, and at least 100 people. Generally, sinkholes are caused by underground rivers or stores of water which erode bedrock and cause the ground above to collapse. Guatemala City is largely built on weak materials such as volcano pumice, however, and as such its sinkholes open extraordinarily quickly, leaving little time for escape.

3. How do Freezing and Thawing break rocks?

Water expands by 9% when it freezes and wedges the rock.

Mechanical weathering

1. Water fills a crack in a rock.

2.The water freezes and the pressure as the ice expands

makes the crack become wider.

3. As this process is repeated, the rock

eventually breaks into several pieces.

 

http://www.youtube.com/watch?v=_XnCTcjNpuc

Mountains shrink because of weathering and erosion.

4. How do glaciation carve land?

U-shaped valley

Ablation is removal of material from the surfaceAbrasion is the mechanical scraping of a rock surface by friction between rocks.Plucking or pulling off rocks.Accumulation or gathering into a heap mass.

http://www.youtube.com/watch?v=XOGbOOaPHsw

Glacial erosion carves the land.

5. What is an Avalanche?

mass of snow, ice, and rocks falling rapidly down a mountainside.

Gravity

High slope

6. Running water causes ___.

Gully Erosion

Rill erosion

7. What is Soil creep?

Creep the slow downward progression of rock and soil down a low grade slope.

Fence is NO longer straight!

GravityLow

slope

8. What is slumping

Slumping –is the movement of loose rock and soil that moves a short distance down a slope.

9. What is a Rockslide?

Rockslide is a type of landslide where rocks tumble downhill loosening other rocks on its way and smashing everything in its path.

Gravity

High slope

10. What is Deflation(Wind Erosion)?

Deflation- erosion of land by wind; can lower the land's surface by several meters

11. What is foliation? Foliation is a weathering process that causes rock layers to peel away due to heat, water, and wind.

12. What is graded bedding?At the bottom of a river, graded bedding is the way sediment settles -- large pieces on the bottom, medium sized pieces next, and then the smallest particles on the top.Sedimentation is the settling of sediments

13. How does a V-shaped Valley form?

A river valley is created when rivers carve into mountains.Water is the greatest agent of erosion.

14. How does a U-Shaped Valley form?

U-shaped valleys made when glaciers scraped through land areas.

Glacier is slowly moving ice due to gravity.

15. How can wind be a mechanical agent of weathering?Wind-blown sand or other particles chip away tiny bits of rock from the surface of exposed rock. This leaves rock with unusual shapes.

16. What is root wedging?

Root grows in cracks and wedges until the rock breaks.

These are living things known as lichens that cause chemical weathering by releasing weak acid.

17. How do lichens breaks rocks?

http://www.youtube.com/watch?v=Te4qnLkHnS4

18. What are lichens ( biological weathering)?

Time lapse- Lichens

Lichens are composite organisms consisting of a fungus and a photosynthetic partner growing together in a symbiotic relationship.

19. What are barrier islands?

Barrier Island is a narrow island of sand that lies parallel to a shoreline.

Barrier Island of North Carolina

Barrier islands protect the coastlines from erosion and severe storm surge and they harbor several habitats that are refuges for wildlife.

20. Why are barrier islands important?

Erosion by gravity

glaciationavalanche

Soil creep

Rock slide

Ice (slow)Snow ( fast)

Soil (slow)Rocks ( fast)

Use Venn diagram to compare glaciation, avalanche, soil creep, rock slide and lahar.

lahar (volcano)