Define the term glacial budget.
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Define the term glacial budget.
The glacial budget is the balance between accumulation and ablation over a year.
What is the accumulation zone?
The accumulation zone is the upper part of a glacier, where inputs are usually greater than outputs.
State the meaning of ablation zone.
The ablation zone is the lower part of a glacier where output exceeds input.
Define mass balance.
Mass balance is the difference between accumulation and ablation over a specific period of time.
True or False?
Ablation is the gain of ice mass on a glacier.
False.
Ablation is the loss of ice mass from a glacier.
True or False?
Glacial ice appears blue because it absorbs short-wave light.
False.
Glacial ice appears blue because it absorbs long-wave light and scatters short-wave blue light.
Define the pressure melting point (pmp).
The pressure melting point (pmp) is the temperature at which ice melts at a given pressure.
What effect does air pressure have on the melting point of ice?
As air pressure increases, the temperature at which ice melts lowers.
What does negative mass balance mean?
Negative mass balance occurs when ablation is greater than accumulation, leading to glacier retreat.
What is positive mass balance?
Positive mass balance occurs when accumulation is greater than ablation, leading to glacier advance.
Define carbonation in relation to glacial processes.
Carbonation is the process in which calcium carbonate in rocks reacts with acidic water to form calcium bicarbonate, which is soluble and removed in solution by glacial meltwater.
True or False?
Nivation occurs only through physical weathering.
False.
Nivation includes both physical and chemical weathering processes.
Define basal sliding.
Basal sliding refers to the movement of a glacier facilitated by meltwater acting as a lubricant between the ice and bedrock.
Define internal deformation.
Internal deformation is the process where ice crystals within a glacier reorient and slide past one another, causing the glacier to move.
True or False?
Cold-based glaciers primarily move through basal sliding.
False.
Cold-based glaciers move mainly through internal deformation.
What is the definition of rotational flow?
Rotational flow is the movement of glacial ice in a circular motion, often in depressions or hollows, as it flows downslope.
True or False?
Repeated cycles of melting, freezing, and transportation result in nivation hollows.
True.
Nivation hollows are formed through repeated cycles of melting, freezing, and transportation.
Define extensional flow.
Extensional flow happens when the ice mass thins and moves faster because the slope is steeper, making erosion less likely.
Define compressional flow.
Compressional flow is the thickening and deceleration of glacier ice as it moves over gentler slopes, increasing erosional potential.
State the meaning of regelation.
Regelation is the process where pressure melting occurs on the upslope of a rocky outcrop and refreezes on the downslope, aiding glacier movement over obstacles.
Define subglacial transport.
Subglacial transport occurs when the moving ice drags materials beneath the glacier.
What is supraglacial transport?
Supraglacial transport is the movement of weathered material on the surface of the glacier.
What is a periglacial landscape?
A periglacial landscape is an area where soil and rock have not risen above 0 °C for at least 2 consecutive years.
What is permafrost?
Permafrost is ground that remains completely frozen (0 °C or colder) for at least two consecutive years.
True or False?
Soil moisture controls permafrost.
False.
Permafrost is not controlled by soil moisture, as ice does not need to be present.
Define talik.
Talik is an area of unfrozen ground within the permafrost.
What is an active layer in a periglacial environment?
The active layer is the top layer of soil that thaws during the summer and refreezes in the winter, with a depth of between 2 cm and 5 m.
What does the term felsenmeer mean?
Felsenmeer means 'field of rocks' in German and refers to areas littered with angular rocks weathered through freeze-thaw processes.
Define frost heave.
Frost heave is the process by which the expansion of ground ice forces soil fragments or small stones to the surface.
True or False?
Solifluction occurs only as a fast process.
False.
Solifluction can occur as both fast and slow processes.
Describe the processes of frost contraction and ice wedging.
Frost contraction and ice wedging occur when the active layer freezes and contracts, forming cracks. Meltwater fills these cracks during thawing, and refreezing forms ice wedges, which can enlarge over time.
What is the difference between continuous and discontinuous permafrost?
Continuous permafrost consists of large, unbroken stretches of frozen ground, while discontinuous permafrost has some small, localised unfrozen areas (talik).