Transcript Weathering_and_Erosion_nina - Tectonics Observatory at Caltech

April 22, 2011
Nina Lin
1999, Mw 7.6
2007
Pasadena
Taiwan
2001 summer
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
Q: What causes the soil wedge in the
rocks (if not ice)?
A. rodents
B. plants
C. human beings
Plant Roots
Q: What causes the holes in the soil?
A. farmers
C. animals
B. electric drills
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!
Q: What is the lichen doing on the rock?
A. Sleeping
B. Meeting friends
C. Destroying the
rock
D. Learning Chinese
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 up
by themselves
C. human beings
River Erosion
River Erosion
When there’re more water than rocks…
River Erosion
When there’re more rocks than water…
Q: How is the U-shaped valley formed?
A. human beings B. snow/ice
C. The hills open up by themselves
Glacier
• the river of snow/ice!
Glacier
flows 30-60 feet/day!!!
Glacier
- leaves scratches, or even pluck boulders!
Q: What causes the holes in the rock?
A. bees
B. ants
C. wind
D. human fingers
Wind Erosion
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
Q: What causes the landslide?
A. grass on the surface
B. houses below the
landslide
C. worms in the soil
D. the weight of the
rocks and soils
Landslide
The erosional process that causes
most damages to human beings!
Q: What may have happened to the house?
A. a big earthquake happened
B. a big tsunami hit
C. a big storm came with big waves
D. all of the above
Coastal Erosion
Summary for Erosional Processes
Game Time!!!