Transcript Mass Movements - Red Hook Central School District

Erosion and Mass
Movements
Erosion
 Erosion
causes the wearing away and
lowering of Earth’s land and surface
features as it transports material
away
 The sun fuels the water cycle and the
forces of erosion
Mass Movements
Triggers of Mass Movements
Mass Movement: The transfer of rock
and soil downslope due to gravity
Factors that trigger mass movements:
• Water-saturated Surface
• Over-steepening of Slopes
• Lack of Vegetation
• Earthquakes
.
Mass Movements
Types of Mass Movements
 Mass movements are classified
on the kind of material that
moves, how it moves, and the
speed of movement.
 Rockfalls/Debris Fall: When
rocks or rock fragments fall
freely through the air.
Mass Movements
Types of Mass Movements
Debris Flow: In a
debris flow, a block of
• Speed: 1 mm/ day to 1 km/hr
material moves
suddenly along a flat,
inclined surface
Heavy Rains Can Trigger
Slumps
Mass Movements
Types of Mass Movements
Flows include:
Avalanches
Mudflows
•Mudflows
Landslides
Mass Movements
Types of Mass Movements
 Creep: the slow, downhill movement of
soil
 Soil Creep moves more material per year
than any other mass movement- even
though it is slow, it is constantly
happening
*Creep can cause: Cracked roads, leaning
utility poles, and bent trees