April 22, 2011Nina Lin

TaiwanPasadena

1999, Mw 7.6 2001 summer

2007

Weathering

• The breakdown of Earth’s surface materials into smaller pieces in the same place.... (SLOWLY!!!)

-Physical Weathering

-Chemical Weathering

Physical Weathering

• Process by which rocks are broken down into smaller pieces by external conditions.

Q: What causes this fracture?

A. ice

B. the foot in the picture

C. aliens

Ice Wedging

A. rodents

B. plants

C. human beings

Q: What causes the soil wedge in the rocks (if not ice)?

Plant Roots

A. farmers B. electric drillsC. animals

Q: What causes the holes in the soil?

Burrowing of Animals

Chemical Weathering

• The process that breaks down rock through chemical changes.

Q: What causes a sinkhole?

A. the houses nearby

B. the trees nearby

C. water

D. human beings

Water slowly dissolves rock...

• Limestone + Water “Karst” features!

Water slowly dissolves rock...

• Sinkholes is the most disastrous Karst feature!

A. Sleeping

B. Meeting friends

C. Destroying the rock

D. Learning Chinese

Q: What is the lichen doing on the rock?

Living Organisms

• Lichens that grow on rocks produce weak acids that chemically weather rock (SLOWLY!!)

Summary for Weathering

Erosion

• The breakdown of the materials of Earth’s crust into smaller pieces and transport of the materials.... (FAST!!!)

Q: How is the V-shaped valley formed?

A. water

B. The hills open upby themselves

C. human beings

River Erosion

When there’re more water than rocks…

River Erosion

When there’re more rocks than water…

River Erosion

Q: How is the U-shaped valley formed?

B. snow/ice

C. The hills open up by themselves

A. human beings

Glacier

• the river of snow/ice!

Glacier

flows 30-60 feet/day!!!

- leaves scratches, or even pluck boulders!

Glacier

A. bees

B. ants

C. wind

D. human fingers

Q: What causes the holes in the rock?

Wind eats out the soft part, and leave the strong part of the rock!!

Wind Erosion

An extreme type of wind erosion:Sand storm!

Persian Gulf

Wind Erosion

A. grass on the surface

B. houses below the landslide

C. worms in the soil

D. the weight of the rocks and soils

Q: What causes the landslide?

Landslide

The erosional process that causes most damages to human beings!

A. a big earthquake happened

B. a big tsunami hit

C. a big storm came with big waves

D. all of the above

Q: What may have happened to the house?

Coastal Erosion

Summary for Erosional Processes

Game Time!!!