Chapter 12.3 Second and third period

1. WEATHERING, SOIL,
AND EROSION
12.3 Mass Movement and Erosion

2. KNOW
mass movement slump
erosion earthflow
talus mudflow
landslide volcanic neck
creep

3. UNDERSTAND
Mass movements and erosion carry away weathered
materials and reshape Earth’s surface.

4. DO
Give examples of mass movement.
Explain how erosion reshapes Earth’s surface.

5. Ocean waves and
Earthflow
currents
Rivers and Mudflow
streams
Glaciers Slump
Creep
Wind
Agents of erosion Types of landslides

6. EXPLAIN IN TWO OR THREE SENTENCES
HOW CLIMATE AND ROCK COMPOSITION
AFFECT RATES OF EROSION.
Because water is a powerful agent of
erosion, regions with humid climates
tend to have rounded (more eroded)
topography. Some types of rock tend
to weather easily, whereas others,
such as igneous rock, tend to resist
weathering agents.

7. BRIEFLY DEFINE EACH TYPE OF
LANDSLIDE YOU NAMED IN THE
GRAPHIC ORGANIZER ABOVE.
Creep: a slow movement of soil down a slope
Slump: the movement of blocks of land downward along a
sloping surface.
Mudflow: the rapid movement of large amounts of clay and
silt suspended in water.
Earthflow: the slow movement of weathered material
saturated with water.

8. 12.3 #1. EXPLAIN WHAT THE TERM
MASS MOVEMENT MEANS, AND GIVE
SOME EXAMPLES OF MASS MOVEMENT.
12.3 #1. Mass movement is the downward
transportation of weathered materials by
gravity. Examples include landslides,
creep, slump, earthflows, and mudflows.

9. Earthflows
Classic slump
earthflow

10. Mudflows

11. #2. EXPLAIN HOW THE CLIMATE OF
A REGION AFFECTS EROSION AND
TOPOGRAPHY.
#2. Climate determines the types of
erosion that dominate in a region,
which determine the topography. In
humid climates, water is an effective
agent of erosion. As a result, the
topography tends to be rounded. In
dry regions, the topography tends to
be sharp and jagged.

12. Rounded
topography

13. Bryce Canyon, Ut
Garden of the Gods
Colorado Springs, Co
Natural Bridges, Ut

14. #3. VOLCANOLOGISTS OFTEN STUDY THE AREA AROUND A
VOLCANO TO IDENTIFY PLACES WHERE LAHARS HAVE
OCCURRED IN THE PAST. HOW COULD SUCH STUDIES
BENEFIT COMMUNITIES NEAR THE VOLCANO?
#3. Where lahars have occurred in the
past, they may be likely to occur in the
future. Thus studying lahars may help
prevent deaths and future damage to
communities.

15. Mt. St. Helens, Wa

16. #4. GRAVITY IS A FORCE THAT PULL OBJECTS
DOWNWARD. FRICTION IS A FORCE THAT RESISTS THE
SLIDING MOTION OF ONE SURFACE AGAINST ANOTHER
SURFACE. EXPLAIN HOW THESE FORCES AFFECT ROCKS
AND EARTH ON A MOUNTAIN SLOPE.
#4. Gravity causes mass movement of
material down a mountain slope.
Friction opposes gravity and thus acts to
hold rocks on a mountain slope.