Chapter #5 Flashcards
Relief is…
Differences in elevation between location
Slope is….
Tilted ground between locations at different elevations
Erosion is …
The removal of material due to the movement of ice, water, and air
Name the 4 angles and their degrees
Gentle: < 5
Moderate: 5 - 35
Steep: > 35
Vertical: 90
What is the slope on roads called?
Grade
What is Grade (of land) measured in?
Percentage
Most slopes are of which type?
Complex
Name the 6 types of slopes
Planar
Convex up
Concave up
Complex (convex-concave)
Vertical
Stair-step
Slope Shape depends on what 3 factors?
Strength, Climate, Formation Process
Define Strength, with slope shape
- The ability to avoid failure,
- Coherent material is a continuous solid,
- Unconsolidated material is composed of separate pieces,
- Planes of weakness are weakly attached surfaces
Define Climate, with slope shape
- Long term atmospheric conditions
- Determines running water, flowing ice, and wind
- Controls vegetation and soil characteristics
Define Formation Process, with slope shape
- Different erosion processes create different slope shapes.
Glacial erosion creates what shape?
A “U” shape
Steam flow erosion creates what shape?
A “V” shape
Class Question #1
Why is the event at Yungay, Peru, classified as a secondary disaster?
a) The flood that inundated Yungay was created from volcanism in
Nevado Huascarán that melted a glacier.
b) The primary seismic waves created only minimal damage to Yungay
compared to the surface waves that arrived later.
c) The landslide that buried Yungay was created by an MW 7.9
earthquake.
d) The pyroclastic flow that buried Yungay was created only after a
mafic volcanic eruption.
( NO PROVIDED ANSWER YET)
Vectors indicate what?
Magnitude and Direction (Force direction specifically)
What is the formula for Stress
Stress = Force (divided) Area
What is Normal Stress?
Force that is perpendicular to the surface
What is Shear Stress?
Force that is parallel to the surface
What is Resistance Stress?
Frictional resistance of motion
A slope is unstable when?
Force D > Force R
What is the formula for Safety Factor?
Safety Factor = Force R (divided) Force D
What are joints?
Cracks
Factors causing joint growth
- Increasing σd (downslope shear stress)
- Overburden removal
- Ice and root wedging
- Daily temperature changes
Sedimentary rock joints are often ___ to beds
perpendicular
Igneous rock joints are often _______ to beds
perpendicular or parallel
Exfoliation joints are
joints that are parallel to beds
Cohesion
Weak electrical charges attract grains to each other
Too much what does what to Cohesion?
Eliminates cohesion by seperating grains, eliminating electrical attraction
A cones steepest angle is its?
Repose