key words Flashcards
What is the meaning of terracettes?
Small terraces from a few centimetres to 0.5m across the face of a slope caused by soil creep or solifluction.
What is the meaning of periglacial?
On the edge of glacial conditions, that is, an area which is covered by snow and ice for some of the year but also experiences a thaw for part of the year. Periglacial areas are commonly affected by intense freeze-thaw activity.
What is the meaning of aspect?
The direction a slope faces; for example, north- and south-facing slopes.
What is the meaning of decomposition?
Chemical weathering of rocks creating new materials.
What is the meaning of disintegration?
Mechanical weathering of rocks resulting in smaller fragments of the same type.
What is the meaning of in situ?
On the spot, that is, without any lateral (sideways) movement.
What is the meaning of exfoliation?
The ‘peeling’ of rocks on their outer edges as a result of repeated thermal expansion and contraction.
What is the meaning of pools?
The deep parts of a river located on the outer bend of a meander.
What is the meaning of riffles?
The ridges - often formed of gravel - found in the straight part of river between two meanders.
What is the meaning of cavitation?
The explosion of air in joints and cracks as a result of air at a very high pressure.
What is the meaning of hydraulic radius?
The cross sectional radius of a river divided by the wetted perimeter.
What is the meaning of the wetted perimeter?
The total length of the bed and base of a river channel in contact with the water in a river.
What is the meaning of the sediment yield?
The amount of material (debris) carried away by water. Often measured in t/km/year.
What is the meaning of entrainment?
Picking up particles from the ground/bed of a river.
What is the meaning of unconsolidated rocks?
Loose, broken material that is often easily eroded.
