Ch 13 Weathering, Karst Landscapes, and Mass Movement
The angle of repose depends on the size and texture of the grains.
true
List three forms of physical weathering.
Frost action, salt-cyrstal growth, pressure-release joint
___ threshold is the point at which there is enough energy to overcome resistance against movements.
Geomorphic
The science that specifically studies the origin, evolution, form, and spatial distribution of landforms is
Geomorphology
Chemical weathering is greatest under conditions of
Higher mean annual rainfall and temperature.
In which climates would rock be weathered to the greatest depth?
Hot and wet
Which of the following is true of spheroidal weathering?
It attacks the corners and edges of rocks.
An example of chemical weathering is
Karst topography
Which of the following is true of joints?
Only B and C are true. Joints enable more water to move through the ground.Joints enhance the rate of weathering.
In reality, a landscape behaves as a(an ___ system.
Open
A slope is stable if its strength exceeds the weathering and erosion process.
True
The salt crystal growth is primarily found in arid environments.
True.
Other than the rock itself, the most important chemical substance needed for the majority of weathering processes is
Water
The disintegration and dissolving of surface and subsurface rock is called
Weathering
List two forms of landslides.
Translational and rotational
The dynamic equilibrium model refers to
A balancing act between tectonic uplift and rates of denundation by weathering and erosion in a given landscape.
Movement at the geomorphic threshold signals
A conversion of potential energy to kinetic energy.
A landslide differs from a debris avalanche in that
A landslide moves more slowly than a debris avalanche.
The form that a landscape exhibits results from a balance between
ALL OF THE ABOVE Forces acting on the landscape. Endogenic & exogenic processes. Input and outputs of matter and energy.
Landslides occur when
ALL OF THE ABOVE. A threshold is reached. The internal friction is overcome by the force of gravity. Driving forces exceed resisting forces.
Which of the following can lead to hillslope failure?
ALL OF THE ABOVE. Making a road cut in the side of a hill. Increasing the slope angle. Excessively watering a slope.
The rate at which rocks weather depends on
ALL OF THE ABOVE. The climate of an area. The types of rock. The amount of vegetation on an area.
After a threshold is crossed, the landscape
Adjust to a new equilibrium condition.
The steepness of a slope made of loose material is called the
Angle of repose
All processes that cause reduction and rearrangement of landforms are included in the term of
Denudation
Physical weathering dominates in warm and wet climates.
False
On which part of a slope would rocks tend to fall at the highest speed?
Free face
Exfoliation occurs because
Overlaying rock is removed, thereby allowing the underlying rock mass to expand and fracture.
When rock is broken and disintegrated without dissolving, the process in operation is
Physical weathering
Uplift of the lanscape creates ___ energy which is converted to ___ energy when materials begin to move downslope.
Potential; kinetic
In most areas, the upper surface of bedrock is partially weathered to broken-up rock called
Regolith
Human-induced mass movements produce a category of processes known as
Scarification
A slow persistent mass movement of surface soil is called
Soil creep
The pressure-release jointing is a physical weathering process that does not involve water.
TRUE