Geography Exam 3 Chapter 14

Karst Topography

limestone region with a specific landscape of pitted, bumpy surface topography, poor drainage, & well developed solution channels underground (due to chemical weathering)

Debris Avalanche

mass of falling and tumbling rock, debris, and soil

Slope Erosion

material loosened by weathering susceptible to erosion and transportation, for material to move downslope forces of erosion must overcome other forces (friction, inertia & cohesion of particles to one another)

Unstable Slope

materials are weaker than the weathering and erosion processes (steep slope, sand soil)

Mudflow

more fluid than earthflow

Water content in the slope material is highest during which of the following types of mass movement? a)Mudflow b)Earthflow c)Rockfall d)Debris avalanche e)Translational slide

mudflow

Landscape System

open b/c has inputs of energy and materials, inputs are water from precipitation, rocks from tectonic activity

Exfoliation occurs because a)water combines with minerals and increases their size, thereby causing surrounding minerals to pop out of the rock matrix b)water freezes in joints and expands c)overlaying rock is removed, thereby allowing the underlying rock mass to expand and fracture d)All of the above are possible causes of exfoliation

overlaying rock is removed, thereby allowing the underlying rock mass to expand and fracture

Bedrock

parent rock from which weathered regolith and soils develop

Mass Movement Mechanics

physical and chemical processes weaken surface of landscape and make it more susceptible to pull of gravity

Geomorphic Threshold

point at which there is enough energy to overcome resistance against movements

Uplift of the landscape creates ___________energy which is converted to _________energy when materials begin to move downslope. a)kinetic; potential b)potential; kinetic c)potential; chemical d)kinetic; chemical

potential; kinetic

Climatic Conditions

precipitation, temperature, and freeze-thaw cycles, physical weathering in drier/cooler climates, chemical weathering in wetter/warmer climates

Weathering

process breaks down rocks by disintegrating into mineral particles or dissolving into water

Subsurface Water

promotes weathering from below by acting slowly and decomposing near-to-surface rock material

In most areas, the upper surface of bedrock is partially weathered to broken-up rock called a)parent rock b)bedrock c)sediment d)regolith

regolith

Potential Energy

related to elevation

Kinetic Energy

related to motion

Frost Wedging

repeated freezing (expanding) and thawing (contracting) of water is frost action, or freeze-thaw, breaking rocks apart

Angle of Repose

represents balance between driving force (gravity) and resisting force (friction and shearing)

Physical Weathering

rock breakage without any chemical alteration

Pressure-Release Jointing—Exfoliation Process

rocks peel or slip-off in sheets instead of breaking up into grains, removal or shedding of an outer layer by a pressure release from the removal of an overlying rock

Human-induced mass movements produce a category of processes known as a)debris flows b)denudation c)scarification d)translational slides

scarification

Geomorphology

science of landforms including origin, evolution, form, and spatial distribution of landforms

Exogenic processes develop...

sequential landscapes (low relief, gradual change, and stability)

A slow, persistent mass movement of surface soil is called a)a debris avalanche b)soil creep c)a soil slide d)a rock fall

soil creep

Earthflow

soil is saturated, flow will occur

Stable Slope

strength exceeds the weathering and erosion processes (gentle slope, hard rock)

Landslide

sudden rapid movement of a cohesive mass of regolith or bedrock that is not saturated with moisture (traditional or rotational)

Rockfall

volume of rock that falls through the air and hits a surface

After a threshold is crossed, the landscape a)remains unstable there after b)adjusts to a new equilibrium condition c)looks identical to the landscape that existed prior to the crossing of the threshold d)Any of the above are equally likely to occur

adjusts to a new equilibrium condition

Denudation

any process that wears away or rearranges landforms (weathering, mass movement, erosion, transportation, deposition)

Dynamic Equilibrium

balancing act between tectonic uplift and reduction by weathering and erosion

Regolith

broken-up rock due to weathering

Vegetation

can protect rock by shielding it from raindrop impact, roots can stabilize soil

Parent Material

consolidated or unconsolidated material from which soils develop, ranging from unconsolidated sediments and weathered rock to bedrock

Slope Orientation

controls slope's exposure to Sun, wind, and precipitation, (facing away from solar radiation are cooler, moister, more vegetated than slopes in direct sunlight... aka don't bake under sunlight (-: )

All processes that cause reduction and rearrangement of landforms are included in the term of a)mass movement b)erosion c)weathering d)denudation

denundation

Delicate Arch in Utah is an example of a)a geological structure created by flowing ice b)a volcanic dome c)differential weathering d)an extinct shield volcano

differential weathering

Mass Movement Types (4)

fall, slide, creep, flow

Joints

fractures or separations in rock that occur without displacement of the sides, increases the surface area of rock exposed to both physical and chemical weathering

On which part of a slope would rocks tend to fall at the highest speed? a)Concave slope b)Convex slope c)Debris slope d)Free face

free face

Scarification

humans cause disturbance of a slope by highway roadcut, surface mining, housing development, forest clear-cut

Erosion

includes weathering & transport of materials to different locations

Endogenic processes build...

initial landscapes

Geomorphic Cycle

1)Equilibrium stability 2)A destabilizing event (i.e., exceed geomorphic threshold) 3)A period of adjustment 4)Development of a new and different condition of equilibrium

5 Factors Influencing Weathering Processes

1.Rock composition and structure (jointing) 2.Climatic conditions 3.Subsurface water 4.Slope orientation 5.Vegetation

Which of the following is true of spheroidal weathering? a)It is a physical weathering process b)It is a type of exfoliation associated with pressure release c)It attacks the corners and edges of rocks d)It is a frost-thaw action

It attacks the corners and edges of rocks

Salt-Crystal Growth (Salt Weathering)

water on the surface of rocks evaporates & dissolved minerals in the water grow crystals, crystals grow and enlarge & exert force to spread apart individual mineral grains and begin breaking up the rock

Sinkholes

weathering of limestone landscapes creates sinkholes, form in circular depressions and caverns

The dynamic equilibrium model refers to a)a balancing act between tectonic uplift and rates of denudation by weathering and erosion in a given landscape b)a theory involving the cyclic or evolutionary development of a landscape c)a sequential development of landforms d)an important concept first stated by Alfred Wegener

a balancing act between tectonic uplift and rates of denudation by weathering and erosion in a given landscape

Chemical Weathering Processes

act on joints in granite to dissolve weaker minerals