Assess the relative importance of water and ice in the development of landscapes of glacial and periglacial deposition.

AO1 – Knowledge and understanding of the roles of ice and water in shaping glacial and periglacial landscapes of deposition.

AO2 – Applies knowledge and understanding to the context of the question in analysing and evaluating the aspect of relative importance. Compares, contrasts and shows the inter-relationships between water and ice.

Notes for answers

AO1

The physical characteristics of cold environments: Climate. This is important in identifying that climate has a direct impact on the presence of ice or water (or both) in cold environments.
The global distribution of past and present cold environments (polar, alpine, glacial and periglacial) and of areas affected by the Pleistocene glaciations. This depends upon the thrust of the response. Responses should see the link between the climate and the geographical location, perhaps referring to latitude, continentality and/or altitude.
Glacial systems to include the concept of the glacial budget. Ablation and accumulation – historical patterns of ice advance and retreat. Those considering ablation will see the link between glacial and fluvioglacial deposition.
Warm and cold based glaciers: characteristics and development. These types should be linked to glacial and fluvioglacial deposition.
Geomorphological processes – weathering: frost action, nivation; ice movement: internal deformation, rotational, compressional, extensional and basal sliding; transportation and deposition. This may be used to support analysis around the sources of materials for deposition by both water and ice.
Fluvioglacial processes: meltwater, erosion transportation and deposition.
Periglacial features and processes: permafrost, active layer and mass movement. Periglacial landforms: patterned ground, ice wedges, pingos, blockfields, solifluction, lobes, terracettes, thermokarst. Characteristic periglacial landscapes. This may be used to support analysis around the development of solifluction lobes. Origin and development of landforms and landscapes of glacial deposition: drumlins, erratics, moraines, till plains. Characteristic glaciated landscapes.
Fluvioglacial landforms of deposition: kames, eskers, outwash plains. Characteristic fluvioglacial landscapes. There should be clear links to climate and geographical location in differentiating the role of fluvioglacial and glacial deposition.

AO2

Analysis – Expect to see students categorise deposition into the depositional action of the ice, ie formations of moraine and how this is linked but distinct from fluvio-glacial deposition.
Analysis – In order to develop their ideas around deposition of moraine (ground, terminal, medial, lateral, englacial and supra glacial moraine) responses are first likely to consider erosional processes of plucking and abrasion. This is a reasonable approach as long as the response does not drift too far away from the main thrust. The associated moraines should be considered as glacial drift. The till associated with the glacier is then responsible for creating a very distinct glacial topography comprised of a number of distinct landforms – expect to see reference to drumlins, erratics.
Analysis – Kame and eskers should be juxtaposed with glacial deposition. Whereas moraine is dumped insitu as unsorted regolith. Fluvioglacial deposition occurs under the ice in englacial tunnels leading to the formation of sinuous eskers. Kames form at the margins of the ice and the valley side. The commonality is that both are features of the action of water as opposed to the dumping insitu by melting ice.
Analysis – Some students will consider the link between the moraine and the melting ice at the snout. As ablation occurs, the melting ice releases large volumes of water which then acts to sort the sediments at and beyond the snout. The formation of fluvio glacial deposits is distinct from glacial deposits because, in the main, these deposits are well sorted according to size and weight. Expect to see reference to outwash plains, meltwater channels, braided streams and proglacial lakes.
Analysis – More sophisticated responses may consider periglacial environments where it is combination of freezing and thawing which creates the distinctive landscape features. It is not possible to distinguish processes of erosion transport and deposition in the creation of these landscapes. It is combined action of ice and water which creates features such as solifluction lobes.
Evaluation should recognise that in periglacial environments, it is the combined action of water and ice which generates these deposition landforms ie water and ice are equally important. It is, by definition the freezing and thawing which is responsible for the creation of the distinctive landscape.
Overall Evaluation – Most should conclude that it is the geographical location which determines the relative importance in this regard eg in valley glaciers moraine (and therefore ice) dominated deposition occurs at the margins of the glacier. At the snout, where ablation occurs, fluvio-glacial deposition occurs.

Level 4 Description (16–20 marks)

Detailed evaluative conclusion that is rational and firmly based on knowledge and understanding which is applied to the context of the question. (AO2)
Detailed, coherent and relevant analysis and evaluation in the application of knowledge and understanding throughout (AO2).
Full evidence of links between knowledge and understanding to the application of knowledge and understanding in different contexts (AO2).
Detailed, highly relevant and appropriate knowledge and understanding of place(s) and environments used throughout (AO1).
Full and accurate knowledge and understanding of key concepts and processes throughout (AO1).
Detailed awareness of scale and temporal change which is well integrated where appropriate (AO1).

Glaciated Landscape Development (AQA A Level Geography)

Topic Questions