Mass Movement/ Weathering Procesess

Question 1

Flow

Answer 1

Occurs on slopes between 5 and 15 degrees, often after the regolith has become saturated, and flow then results. Vegetation can be destroyed and speeds range from 1 to 15km per year. Includes mudflows, debris flows and lahars.

Question 2

Landslides

Answer 2

Typically consist of unconsolidated rock. They can be extremely dangerous because they occur very quickly with tremendous force.

Question 3

Soil Creep

Answer 3

Very slow movement, occurring on very gentle slopes because of the way soil particles repeatedly expand and contract in wet and dry periods. when wet, soil particles increase in size and weight, and expand at right angles. when the soil dries out, it contracts vertically. Thus, the soil slowly moves downslope.

Question 4

Slumps

Answer 4

Occur as a wedge or slice of material that moves as one piece along a curved surface. Slumps typically occur where there is loose material or rock.

Question 5

Rockfall

Answer 5

The rapid, free-fall of rock from a steep cliff face. Rock fragments fall from the face of the cliff because of the action of gravity. This is made worse by freeze-thaw action loosening the rock.

Question 6

Boring Molluscs

Answer 6

Molluscs live in aquatic or damp habitats and are able to burrow into the rock, which causes it to erode.

Question 7

Frost Shattering

Answer 7

Also known as Freeze-thaw, occurs in cold climates when temperature are often around freezing point and where exposed rocks contain many cracks. water enters the cracks during the warmer day and freezes during the colder night.

Question 8

Oxidation

Answer 8

Chemical weathering involves the alteration of the chemical and mineralogical composition of the weathered material.

Question 9

Sub-aerial processes

Answer 9

The processes of weathering and mass movement.

Question 10

Weathering

Answer 10

Weathering is the breaking down of rock in situ. It can be divided into mechanical and chemical weathering. Mechanical weathering refers to physical processes like freeze-thaw action and biological weathering.

Question 11

Mass Movement

Answer 11

Mass movement is the movement of surface material caused by gravity. Landslides and rockfalls are examples of very sudden movements of this type. Of course geological agents such as water, wind and ice all work with gravity to cause a leveling of land.

Question 12

Storm Surges

Answer 12

A storm surge is a rise in sea level that occurs during tropical cyclones, intense storms also known as typhoons or hurricanes. The storms produce strong winds that push the water into shore, which can lead to flooding. This makes storm surges very dangerous for coastal regions.