OCR A-Level Geography Physical systems (01), June 2025: Question 2
33 marks · Hard difficulty · Extended Response
Explain the role of energy flows in drumlin formation, calculate and interpret glacial erosion dispersion data, explain patterned ground formation, and evaluate human impact on periglacial versus glacial landscape systems.
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Question text
Option B – Glaciated Landscapes
(a) Explain the influence of flows of energy in the formation of a drumlin. [8]
(b) Study Table 2, which shows valley erosion rates along a glacier in India.
Table 2 Valley erosion rates along a glacier in India
Rate of erosion
Location
(m / year)
Zanskar 1 80
Jobri 30
Bilare Bhang 30
Drang Drung 90
Bhurpu 50
Hamtah 80
Nikarchu 90
Shankalpa 50
Pindari 64
Poting 50
(i) Using Table 2, calculate the mean rate of erosion.
Show your workings. [2]
(ii) The standard deviation for the rate of erosion in Table 2 is 21.7.
State what this indicates about the dispersion (spread) of the data set. [2]
(iii) Explain why standard deviation is a more accurate measure of dispersion (spread) than range
and interquartile range. [2]
(c) Study Fig. 2, a periglacial landscape in Iceland.
With reference to Fig. 2, explain the influence of one geomorphic process in forming landform B
(patterned ground). [3]
(d)* ‘Periglacial landscape systems are influenced more by human activity than glacial landscape
systems.’
To what extent do you agree with this statement? [16]
Mark scheme
Show the mark scheme
Question Answer Mark Guidance
2 (a) Explain the influence of flows of energy in the 8 Indicative content:
formation of a drumlin. AO1 x8 AO1 – 8 marks
Knowledge and understanding of the reasons for the
Level 3 (6-8 marks) influence of flows of energy (e.g. kinetic, thermal,
Demonstrates thorough knowledge and understanding gravitational) in the formation of a drumlin could
of the influence of flows of energy in the formation of a potentially include:
drumlin. (AO1). • A mound of glacial debris that has been
streamlined into an elongated hill
This will be shown by including well-developed ideas • Basal ice layers melt due to increased thermal
with a clear appreciation of the reasons for the
energy caused by friction so subglacial debris
influence of flows of energy in the formation of a
gets caught in the uneven ground creating
drumlin.
increased friction
Level 2 (3-5 marks) • This reduces kinetic energy as the glacier speed
Demonstrates reasonable knowledge and reduces encouraging more deposition
understanding of the reasons for the influence of flows • As glaciers re-advance (decrease in thermal
of energy in the formation of a drumlin. energy, increase in accumulation) deposited
material can be reshaped as glaciers have
This will be shown by including developed ideas with greater kinetic energy as they grow leading to
some appreciation of the reasons of the influence of increased erosion of deposits
flows of energy in the formation of a drumlin. •
If drumlins are in lowland areas, they can be
formed as the ice thins due to increased thermal
Level 1 (1-2 marks)
Demonstrates basic knowledge and understanding of energy due to increased air temperatures or
the reasons for the influence of flows of energy in the decrease in altitude, both contributing to thinner
formation of a drumlin (AO1). ice, with reduced energy to carry material,
leading to increased deposition
This will be shown by including simple ideas and with • A core of resistant rock in the path of the glacier
no or limited appreciation of the reasons for the reduced kinetic energy leading to deposition of
influence of flows of energy in the formation of a large layers of till
drumlin.
0 marks
No response or no response worthy of credit.
Question Answer 16 Mark Guidance
2 (b) (i) Study TABLE 2, which shows valley erosion rates 2 AO3 - 2 marks
along a glacier in India. Using TABLE 2, calculate AO3 x2 1 x 1 (✓) for calculating the mean rate of erosion using
the mean rate of erosion. Show your workings. TABLE 2.
1 x 1 (✓) for showing workings.
• 80+30+30+90+50+80+90+50+64+50 / 10 ( ) or
614 / 10 ( )
• Mean value is 61.4 ( )
2 (b) (ii) The standard deviation for the rate of erosion in 2 AO3 – 2 marks
TABLE 2 is 21.7. State what this indicates about the AO3 x2 1 x 1 (✓) for general point about dispersion
dispersion (spread) of the data set. 2 x 1 (✓) for specific point about dispersion
• The sample suggests that approximately 68% of
the values ( ) lies in the range 39.7 – 83.1
(within 21.7 of the mean) ( )
• The sample is fairly spread out around the mean
/ limited clustering (✓) but there are a couple of
locations more than one SD from the mean e.g.
Drang Dung (90) (✓)
• The sample suggests that 6/10 or 60% of the
values ( ) lie within 1 SD of the mean / within
21.7 ( )
2 (b) (iii) Explain why standard deviation is a more accurate 2 AO3 – 2 marks
measure of dispersion (spread) than range and AO3 x2 1 x 1 (✓) for explanation of why standard deviation is
interquartile range. more accurate than the range
1 x 1 (✓) for explanation of why standard deviation is
more accurate than the interquartile range
• Standard deviation is more useful than the
range which only uses the maximum and
minimum value so gives you limited information
about the spread of data ( )
• Standard deviation is more useful than the
range, as the range can be skewed by
outliers/anomalies’ ( )
• Standard deviation is more useful than the IQR
which only uses half the values / the middle 50%
of the data set ( )
• The range only uses the highest and lowest
values ( )
2 (c) Study FIG. 2, a periglacial landscape in Iceland. 3 Indicative content:
With reference to FIG. 2, explain the influence of AO2 x3 AO2 – 3 marks
ONE geomorphic process in forming landform B For analysing Fig. 2 to explain the influence of ONE
(patterned ground). geomorphic process in forming landform B (patterned
ground)
• Patterned ground is due to frost heave and the • Naming a geomorphic process of its own is not
refreezing and expansion of the ground ( ) sufficient for a mark.
causing sediment to be lifted up (DEV). Then • A geomorphic process must be present within
the stones roll down due to gravity causing the the answer to achieve full marks.
patterned ground (DEV)
• Freeze- thaw weathering when water percolates
into the bedrock below ( ) this freezes in the
winter months expanding by 9-10% (DEV)
growing the surface into domes causing
deposition to settle at the base of the dome
creating the polygon patterns (DEV)
2 (d*) ‘Periglacial landscape systems are influenced more 16 Indicative content
by human activity than glacial landscape systems.’ AO1 x8
To what extent do you agree with this statement? AO2 x8 AO1 – 8 marks
Knowledge and understanding of human activity on
AO1 glacial and periglacial landscape systems could
Level 3 (6-8 marks) potentially include:
Demonstrates thorough knowledge and understanding • Human activity in periglacial environments
of the influence of human activity on glacial and o Tourism – heli skiing and snowboarding,
periglacial landscape systems. resort / airport construction, road building
o Mineral extraction – oil, Trans-Alaskan
The answer should include accurate place-specific pipeline, road / building construction
detail. • Human activity in glacial environments
o HEP generation – dam construction
Level 2 (3-5 marks)
o Highland farming and forestry – mainly
Demonstrates reasonable knowledge and
understanding of the influence of human activity on sheep farming and conifer plantations
glacial and periglacial landscape systems. o Tourism – skiing, mountain biking, hiking,
resort / road construction
The answer should include place-specific detail which AO2 – 8 marks
is partially accurate.
Apply knowledge and understanding to analyse and
Level 1 (1-2 marks) evaluate the extent to which periglacial landscape
Demonstrates basic knowledge and understanding of systems are influenced more by human activity than
the influence of human activity on glacial and periglacial glacial landscape systems. This could potentially
landscape systems. include:
• Importance will vary depending on use of case
There is an attempt to include place-specific detail but study
it is inaccurate. • The annual variation in permafrost results in
greater influence of human activity as more
0 marks construction is needed to manage the human
No response or no response worthy of credit.
activity e.g. roads / pipelines on stilts which
move as soil thaws during summer resulting in
greater solifluction and solifluction lobes
• In periglacial areas the urban heat island effect
can increase the thermokarst creating alases
AO2 which are significant in area up to 50m in depth
Level 3 (6-8 marks) and 15km in length
Demonstrates thorough application of knowledge and • Glacial HEP schemes have relatively little
understanding to provide clear and developed analysis impact on glacial landforms – heat from the dam
that shows accuracy. Includes a detailed evaluation that reduces glacial advance, however, systems are
offers generally secure judgements, with some link usually built where rivers flow so glacial advance
between rational conclusions and evidence, of the is further upstream
extent to which periglacial landscape systems are
• Sand and gravel extraction in glacial areas often
influenced more by human activity than glacial
landscape systems. use glacial deposits in areas of ablation
reducing impact on glacial environment,
Level 2 (3-5 marks) however quarrying landscape significantly
Demonstrates reasonable application of knowledge impacts slope stability increasing risk of
and understanding to provide sound analysis that landslides
shows some accuracy. Includes a sound evaluation of
Highest level likely to refer to dynamic equilibrium /
the extent to which periglacial landscape systems are
spatial / temporal variations.
influenced more by human activity than glacial
landscape systems. Judgements and conclusions are
generalised, with limited use of evidence.
Level 1 (1-2 marks)
Demonstrates basic application of knowledge and
understanding to provide simple analysis that shows
limited accuracy to provide an un-supported evaluation
that offers simple conclusions of the extent to which
periglacial landscape systems are influenced more by
human activity than glacial landscape systems.
0 marks
No response or no response worthy of credit.
Quality of extended response
Level 3
There is a well-developed line of reasoning which is
clear and logically structured. The information
presented is relevant and substantiated.
Level 2
There is a line of reasoning presented with some
structure. The information presented is in the most-part
relevant and supported by some evidence.
Level 1
The information is basic and communicated in an
unstructured way. The information is supported by
limited evidence and the relationship to the evidence
may not be clear.
How to answer it
Glaciated Landscapes: Processes, Statistics & Human Impacts
What this question tests
A comprehensive assessment spanning geomorphological processes, quantitative statistical analysis, and synoptic evaluation of human impacts on cryospheric systems.
Explain the influence of flows of energy in the formation of a drumlin.
Subglacial Landform Genesis • Systems Approach
💡 Key Knowledge: Energy Flows
- Kinetic Energy: Related to ice velocity, glacier thickness, and mass flux. Regulates erosive capacity vs depositional competence.
- Thermal Energy: Generated by basal friction and geothermal heat flux. Pressure melting point controls the presence of basal water films.
- Gravitational Potential Energy: Drives ice movement down valley or ice sheet gradients, converted into kinetic energy.
- Streamlining: Subglacial till is deformed and sculpted around an obstacle or lodging core into an elongated, oval-shaped hill (stoss-and-lee profile).
✅ Model Explanation
As a glacier flows down-gradient (gravitational potential converted to kinetic energy), basal friction and geothermal heat input generate thermal energy. When basal ice reaches the pressure melting point, meltwater lubricates the bed.
Where basal load becomes excessive or ice thins (reducing kinetic energy and carrying capacity), subglacial lodging occurs. Alternatively, if basal water escapes or the glacier encounters an obstacle, friction spikes, reducing kinetic energy locally and promoting till deposition.
During subsequent ice advance, high kinetic energy remodels and streamlines the till mound: intense pressure shapes the steep, blunt stoss end up-glacier, while ice flow tapers sediment into a gentler, elongated lee slope down-glacier.
🧠 Exam Technique: Securing Level 3 (6–8 marks)
- Name specific energy types: Explicitly mention kinetic, thermal, and potential energy. General references to "glacier power" remain at Level 1/2.
- Link energy change to process: State exactly how an increase or decrease in energy causes deposition (loss of kinetic energy) or streamlining (ice flow kinetic deformation).
❌ Common Errors
- Describing the drumlin's shape only, without linking to the flows of energy requested in the prompt.
- Confusing the stoss and lee orientations (stoss faces up-glacier, lee points down-glacier).
- Failing to mention the role of thermal energy and basal meltwater dynamics.
Quantitative Skills: Glacier Valley Erosion Rates
Data Handling, Standard Deviation & Dispersion Measures
📐 2(b)(i) Calculate Mean Rate of Erosion [2 marks]
Values from Table 2: 80, 30, 30, 90, 50, 80, 90, 50, 64, 50 (m/year).
Step 1: Sum all values (Σx)
80 + 30 + 30 + 90 + 50 + 80 + 90 + 50 + 64 + 50 = 614 [1 mark for workings]
Step 2: Divide by total number of observations (n = 10)
Mean = 614 / 10 = 61.4 m/year [1 mark for correct mean]
✅ 2(b)(ii) Interpreting Standard Deviation (s = 21.7) [2 marks]
- General point (1 mark): The data is fairly widely dispersed/spread out around the mean with limited clustering.
- Specific data-linked point (1 mark): Approximately 68% of the data values lie between 39.7 and 83.1 m/year (Mean ± 1 SD: 61.4 - 21.7 to 61.4 + 21.7). Exactly 6 out of 10 locations (60%) lie within 1 SD of the mean, whilst extreme values like Nikarchu (90) and Bilare Bhang (30) fall beyond 1 SD.
🧠 2(b)(iii) SD vs Range and Interquartile Range [2 marks]
- Compared to Range (1 mark): The range only uses the extreme minimum and maximum values (90 - 30 = 60), ignoring the rest of the dataset and being severely distorted by anomalies or outliers.
- Compared to IQR (1 mark): The IQR only accounts for the central 50% of the dataset, ignoring half of the data (top and bottom 25%). In contrast, standard deviation uses every single data point relative to the mean.
❌ Common Calculation & Statistical Traps
- Forgetting to write out the sum in 2(b)(i), losing the easy workings mark if the final division contains an arithmetic error.
- In 2(b)(ii), simply defining what standard deviation is in theory without stating what it shows about this specific dataset.
- In 2(b)(iii), failing to address both the range and the interquartile range (IQR) to achieve the full 2 marks.
Explain the influence of one geomorphic process in forming patterned ground.
Periglacial Geomorphology • Active Layer Dynamics
✅ Model Answer: Frost Heave
- Process selection: Frost heave / ground water refreezing within the active layer.
- Upward displacement: Water freezes in the active layer, expanding by 9–10% and forming segregated ice lenses. Stones conduct heat faster than fine soil, causing ice beneath stones to freeze first and heave coarse sediments upward toward the surface.
- Lateral sorting & sorting into polygons: Surface doming occurs. Due to gravity, the larger, heaved stones roll down the slight gradient of the dome to collect in depressions around the periphery, forming sorted stone circles/polygons.
🧠 Mark Scheme Rule: Crucial Distinction
⚠️ Examiner Warning: Simply naming a geomorphic process (e.g. "freeze-thaw" or "frost heave") scores 0 marks. Marks are awarded solely for the developed explanation of how that process creates the sorted pattern.
- 1 mark: Initial upward movement caused by frost heave/water freezing.
- 2 marks: Development of ground doming / differential expansion.
- 3 marks: Downslope gravitational movement of coarse clasts to polygon edges.
'Periglacial landscape systems are influenced more by human activity than glacial landscape systems.' To what extent do you agree?
Synoptic Essay: Fragility, Thermal Equilibrium & Spatial Extent
💡 AO1: Case Study Knowledge Base
Periglacial Landscapes (e.g. North Slope Alaska):
- Resource extraction: Oil & gas at Prudhoe Bay; Trans-Alaska Pipeline System (TAPS).
- Mechanisms: Removal of vegetation insulation, heated buildings, and gravel pads induce permafrost thaw → creates thermokarst, thaw lakes, and subsidence (alases up to 50m deep).
- Urban heat island: Anthropogenic warmth elevates local ground temperatures.
Glacial Landscapes (e.g. Swiss Alps, Karakoram):
- HEP Schemes: Grande Dixence Dam (Switzerland) captures meltwater, alters sediment flux, traps bedload, and reduces proglacial discharge.
- Tourism/Recreation: Ski piste grading destabilises slopes, artificial snow alters surface albedo; construction causes moraine scarring.
- Quarrying: Extraction of glacial outwash aggregates disrupts sandur morphology.
🧠 AO2: Developing High-Level Evaluation
- Thermal Equilibrium vs Physical Mass: Periglacial environments are acutely susceptible because thermal equilibrium is easily disrupted; a small positive temperature change permanently destroys permafrost via self-reinforcing feedback loops.
- Spatial Scale: Glacial human impacts (HEP, ski resorts) tend to be localized to specific valleys or ablation zones, whereas periglacial impacts (pipeline corridors, road networks, urban alases) span thousands of square kilometres.
- Engineering Mitigation: Humans employ thermosyphons and elevated piles (e.g. on TAPS) to mitigate permafrost thaw, showing that human impact is an ongoing negotiation rather than purely destructive.
✅ Balanced Evaluative Structure (16/16 Framework)
Introduction: Define both landscape systems. Set up the argument: while glacial landscapes experience intense, localized disruption from tourism and HEP, periglacial landscapes are inherently more sensitive due to delicate thermal equilibrium and irreversible positive feedback loops (thermokarst formation).
Paragraph 1 (Periglacial vulnerability): Detail Prudhoe Bay and Trans-Alaska Pipeline. Discuss thermal disruption: buildings transferring heat to permafrost, gravel road dust reducing albedo, solifluction acceleration. Emphasize that removing the insulating tundra vegetation triggers alases.
Paragraph 2 (Glacial landscape modification): Examine HEP (e.g. Grande Dixence) and tourism (Alpine ski resorts). Detail clear geomorphic changes: reduced sediment flow down-valley, altered discharge regimes, slope reshaping for pistes, moraine quarrying.
Paragraph 3 (Comparative Evaluation / Critical Nuance): Evaluate spatial and temporal scales. Glacial modifications often operate downstream in the proglacial zone without fundamentally destroying the glacier body itself. In periglacial zones, permafrost loss is systemic and permanent once initiated. However, periglacial engineering (thermosyphons, building on stilts) actively mitigates local damage.
Conclusion: Agree to a large extent. Periglacial systems suffer broader, more irreversible disruptions to their fundamental geomorphic processes due to thermal sensitivity, whereas glacial human impacts are largely localized to ablation and proglacial margins.
Topics
1.1.2 Option B – Glaciated Landscapes · 1.1.1 Option A – Coastal Landscapes · 1.1.3 Option C – Dryland Landscapes · Topic 1.2 Earth’s Life Support Systems · 1.a. Glaciated landscapes can be viewed as systems. · 2.a. Glacial landforms develop due to a variety of interconnected climatic and geomorphic processes. · 3.b. Periglacial landforms exist as a result of climate change before and/or after glacial periods. · 4.a. Human activity causes change within periglacial landscape systems. · 4.b. Human activity causes change within glaciated landscape systems. · Topic-specific skills 1.a–4.b
Question and mark scheme from the OCR A-Level Geography examination, Physical systems (01), June 2025. QuestionVault is an independent revision resource; questions remain the copyright of the awarding body.