Visualizing Physical Geography Chapter 10

Front 1

Weathering

Back 1

All the processes that physically disrupt or chemically decompose a rock at or near the Earth's surface.

Front 2

Regolith

Back 2

Layer of mineral particles that lies above bedrock.

Front 3

Physical weathering

Back 3

Breakup of massive rock (bedrock) by physical forces at or near the Earth's surface.

Front 4

chemical weathering

Back 4

Chemical changes in rock minerals through exposure to the atmosphere and water.

Front 5

mass wasting

Back 5

Spontaneous downhill movement of soil, regolith, and bedrock under the influence of gravity.

Front 6

bedrock

Back 6

Solid rock layer under soil and regolith, which is relatively unchanged by weathering.

Front 7

soil creep

Back 7

Extremely slow downhill movement of soil and regolith.

Front 8

earthflow

Back 8

Moderately rapid downhill flow of water-saturated soil, regolith, or weak shale.

Front 9

mudflow

Back 9

flowing mixture of water and soil or regolith that flows rapidly downhill.

Front 10

landslide

Back 10

Rapid sliding of large masses of bedrock on steep mountain slopes or from high cliffs.

Front 11

permafrost

Back 11

Soild, regolith, and bedrock at a temperature below freezing found in cold climates.

Front 12

solifluction

Back 12

A special variety of earthflow in arctic permafrost tundra regions. It occurs in late summer, when the ice-rich layer at the bottom of the active layer thaws to form a plastic mud. Moving almost imperceptibly on the plastic layer, this saturated soil is deformed into solifluction terraces and solifuction lobes that give the tundra slope a stepped appearance.

Front 13

granular disintegration

Back 13

A physical weathering process where water freezes between mineral grains in igneous rocks, separating the grains to create a fine gravel or coarse sand of single mineral particles.

Front 14

capillary action

Back 14

a pocess in which the water's surface tenstion causes it to be drawn through fine openings and passages in the rock.

Front 15

Unloading

Back 15

aka exfoliation. When rocks are weathered away, the rock form deep beneath the Earth's surface expands because it has less pressure on it. This causes the rock to crack in layers.

Front 16

Salt-crystal growth

Back 16

Salt-crystal growth occurs when water evapoates from sandstone pores, leaving tiny salt crystals behind. Over time the force of these growing crustals breaks the sandstone apart, grain by grain.

Front 17

debris flood (or debris flow)

Back 17

The watery type of mudflow in the western United States. They are common in Southern California.

Front 18

alpine debris avalanches

Back 18

Mudflows on steep slops in mountainous regions.

Front 19

Induced mass wasting

Back 19

Mass movements produced by human activities.

Front 20

Scarification

Back 20

General term for excavations and other land disturbances produced to extract mineral resources.

Front 21

Lahars

Back 21

Mudflows on the slopes of erupting volcanoes

Front 22

Ground ice

Back 22

water, in its frozen state, found in pore spaces in the ground.

Front 23

Active layer

Back 23

the shallow surface layer in permafront terrains that thaws with the changing seasons

Front 24

Permafrost table

Back 24

the area below the active layer, marking the upper surface of the permanently frozen zone.

Front 25

Pingo

Back 25

A pingo is an ice-formed feature in the arctic tundra- conspicuous conical mound.

Front 26

What is the difference between physical and chemical weathering?

Back 26

In physical weathering, rocks are fractured and broken apart. In chemical weathering, rock minerals are transformed from types that were stable when the rocks were formed to types that are now stable at surface temperatures and pressures.

Front 27

What is the difference between an earth flow and a mudflow?

Back 27

Mudflows flow much more rapidly then earthflows.

Front 28

How does an ice wedge form?

Back 28

Ice wedges form as ice accumulates in vertical wedge-forms in deep cracks in the sediment.

Front 29

How is a pingo formed?

Back 29

A pingo is formed when a lake above unfrozen ground drains until it is small enough to begin to freeze. Once the water begins to freeze the unfrozen ground does too. When the unfrozen ground freezes it expands, and exerts force on the ground that has not yet frozen. The pressure on the not yet frozen ground is pushed upward, forming an ice dome.

Front 30

What are the environmental problems of permafrost?

Back 30

When humans remove the decaying matter and plants from the surface of the tundra or arctic forest, the summer thaw extends deeper into the ground. Ice wedges and other ice bodies melt and form mud, which is then eroded and transported by water streams, leaving trench-like morasses. This is called thermal erosion.

Front 31

What does weathering produce?

Back 31

Regolith and a number of distinct landforms.

Front 32

What is frost action?

Back 32

Frost action is a process of physical weathering where water penetrates fractures of bedrock and freezes, expanding and causing physical weathering.

Front 33

Explain salt-crystal growth.

Back 33

Salt-crystal growth occurs when water evaporates from sandstone pores, leaving tiny salt crystals behind. Over time the force of these growing crystals breaks the sandstone apart, grain by grain.

Front 34

Where is chemical weathering most effective and why?

Back 34

Chemical weathering is most effective in warm, moist climates of the equatorial, tropical, and subtropical zones because chemical reactions occur more rapidly at warmer temperatures.

Front 35

What triggers soil creep?

Back 35

Soil creep is triggered when soil and regolith are disturbed by alternate drying and wetting, growth of ice needles and lenses, heating and cooling, trampling and burrowing by animals, and shaking by earthquakes.

Front 36

What do severe earthquakes in mountainous regions cause?

Back 36

Landslides.

Front 37

How can human activities induce mass wasting?

Back 37

By creating unstable piles of waste soil and rock and by removing the underlying support of natural masses of soil, regolith, and bedrock.