Key Words Flashcards
Katabatic winds
cold mountains wind - the dense air flows down from the mountains to the lowlands chilling the grounds as it passes over.
Insolation
incoming solar radiation, that is, heat received from the sun.
Orographic rainfall
rain that is produced as air is forced to rise over ground such as mountain barrier, it subsequently cools, condensation occurs, and precipitation is produced.
Striations
scratch marks on a rock caused by abrasion.
Chatter marks
discontinuous scratch marks on a rock caused by abrasion.
Roche montonnee
rock that has been plucked and made smooth by glaciers. Upstream side (stoss) is smooth due to abrasion, while the downstream slope (lee)is steeper and rougher due to plucking.
Divergent flow
ice flow which is around an object rather than over it.
Carbonation
a form of weathering in which calcium carbonate reacts with an acid water to form calcium biocarbonate which is soluble and removed in solution.
Hydrolysis
a chemical weathering process where water reacts with minerals such as feldspars to produce clay minerals.
Till
sediment is deposited by a glacier - unsorted, angular and of variable sized material, till refers to unsorted deposits with a wide range of grain size, deposited directly by the ice - whether on land or below a floating glacier - and not subsequently changed. Sometimes called moraine or boulder clay.
Neve (firn)
a transnational stage between snow and ice. It has survived at least one summers melting, and has been compressed by snowfall the following winter.
Extrusion flow
the movement of ice as a result of becoming too deep or heavy and therefore unstable. It ‘collapses’ and begins to flow outwards as a result of its own weight and pressure.
Bergschrund
a large crack or crevasse.
Randkluft
a gap between the rock face and ice in the hollow, caused when heat from the rock melts the ice.
Pressure release
a type of weathering in which a rock is able to expand outwards as a result of the ‘unloading’ of weight (pressure) and as a result fractures or cracks appear in the rock as it expands.
Spur
a projection of land from a ridge or mountain. Interlocking spurs occur in the upper course of the river valleys, where streams tend to follow winding courses. The projecting spurs appear to overlap or interlock. Truncated spurs are those which have been eroded in their lower parts by glaciers.
Ribbon lakes
long, linear lakes which fill a glaciated trough such as lake Windermere in the Lake District.
Hanging valleys
a small U-shaped valley formed by a small glacier that joins and hangs above a large U-shaped valley formed by a larger glacier.
Scree
angular sediment that collects at the foot of a mountain range or cliff. The rock fragments that form scree are usually broken off by the action of freeze thaw weathering.
Moraine
glacial deposits consisting of poorly sorted, often angular, loose rock fragments. Many forms exists including englacial, laterial, medial. recessional and terminal.
Isostatic uplift
the rising of the land when the weight of a glacier has been removed as a result deglaciation (melting of glaciers)
Col or spillway
a low point in a ridge or high ground often formed as a result of back to back cirques. Some may be formed by the movement of glacier ice from one valley into another and some by glacial diversion of drainage.
Unstratified material
usually glacially deposited material which is unsorted, variable in size and has no distinct layers.
Ablation
the removal of material (ice, debris) from a glacier such as by melting, evaporation, sublimation.
moulins
a circular sink-hole or portal into a glacier. They may be caused by melt water entering a crevasse,
Varved clays
a distinctive banded layer of silt and sand deposited in lakes near the margins of ice-sheets.
Springmelt
the flooding that occurs in spring as a result of melting winter snow.
Perennials
plants living for several years
Net spring productivity
the rate of production of biomass that is available for consumption by herbivores - the next trophic level in the ecosystem.
Podzol
light coloured soil found under coniferous forests and on moorlands in cool regions where rainfall exceeds evaporation. The constant downward movement of water leaches nutrients from the upper layers, making podzols poor agricultural soils. The leaching of minerals such as iron, calcium, and aluminium leads to formation of a bleached zone, often also depleted of clay. These minerals can accumulate lower down the soil profile to form a hard, impermeable layer which restricted the drainage of water down through the soil.
