3.3 Slope processes

Question 1

Mass movement

Answer 1

Downslope movement of rock and weathered debris by gravity alone.

Question 2

Regolith

Answer 2

The surface cover of loose, unconsolidated material including alluvium, glacial deposits, and peat.

Question 3

Soil creep

Answer 3

Slow, downslope movement of unconsolidated material.

Question 4

Heave

Answer 4

The downslope movement of material due to freezing and thawing.

Question 5

Solifluction

Answer 5

Accelerated soil creep that occurs in permafrost areas, even on gentle slopes.

Question 6

Plastic flow

Answer 6

The way solids can deform in a ductile manner under stresses such as gravity.

Question 7

Terracettes

Answer 7

Small ridges, caused by soil creep, running across slopes.

Question 8

Lahar

Answer 8

A mudflow on the slopes of active volcanoes when ash mixes with water from torrential rainstorms.

Question 9

Shear stress

Answer 9

The force acting to cause movement

Question 10

Shear strength

Answer 10

The resistance of a body of rock to gravity

Question 11

Bedding plane

Answer 11

The surface that separates each successive layer of a stratified rock from its preceding layer

Question 12

Planar slide

Answer 12

Weathered rock moves downhill leaving behind it a flat rupture surface.

Question 13

Rotational slide

Answer 13

Rock moves downwards and a curved rupture surface is produced.

Question 14

Sheet erosion

Answer 14

Removal of soil or sediment from the ground surface in a roughly uniform layer.

Question 15

Sheet-wash

Answer 15

Removal of soil from a wide area by a thin sheet of water moving over a gentle slope.

Question 16

Rills

Answer 16

A fine network of channels in the land surface.

Question 17

Shearing

Answer 17

Stresses which slide past each other.