AI-assisted English content review; independent teacher approval pending.
Practice scope and review
Original, AI-authored English practice with worked guidance. Selected topics only; independent teacher review is pending. This is not a complete syllabus, official past-paper collection or predicted exam score. Check your own exam-board specification: these concepts are not certified against a particular board or exam year.
108 original questions across 14 selected topic areas. No account or payment required to practise.
Cambridge International AS & A Level Geography (9696), examination year 2027: AI-assisted conceptual alignment to official sources, not teacher or exam-board certification. Syllabus mapping and remaining coverage.
10 questions in this topic
Exact English revisions checked in an AI-assisted academic review; independent teacher approval is still pending.
All topics
Original English written practice with indicative marking points. Fictional datasets are labelled; real source briefs are bounded. Partial conceptual evidence, not complete syllabus coverage; independent teacher approval pending.
Subtopics in this topic (10)
River processes and discharge
Fluvial landform sequences
Flood causes and unequal impacts
Energy budgets and geographical explanation
Circulation and seasonal climates
Precipitation processes
Climate evidence and baselines
Plate characteristics and motion evidence
Plate boundaries and hazard distributions
Mass movement forms and evidence
10 of 10 questions shown
Loading saved responses
Question 1Fictional measurements divide a river cross-section into three rectangles of widths 2, 3 and 5 m, mean depths 0.5, 1.0 and 0.8 m, and representative mean velocities 0.4, 0.8 and 0.6 m/s respectively. (a) Estimate discharge by summing subsection flows; explain why multiplying unweighted average depth and velocity is unsafe. (b) Explain how turbulent flow can transport sand by saltation and silt by suspension, contrasting traction and dissolved load. (c) Explain hydraulic action and abrasion, then predict how reduced velocity might change deposition without asserting a universal sediment threshold. Locate a thalweg in a labelled bend sketch and contrast laminar, turbulent and helicoidal flow.6 indicative marks
Fictional measurements divide a river cross-section into three rectangles of widths 2, 3 and 5 m, mean depths 0.5, 1.0 and 0.8 m, and representative mean velocities 0.4, 0.8 and 0.6 m/s respectively. (a) Estimate discharge by summing subsection flows; explain why multiplying unweighted average depth and velocity is unsafe. (b) Explain how turbulent flow can transport sand by saltation and silt by suspension, contrasting traction and dissolved load. (c) Explain hydraulic action and abrasion, then predict how reduced velocity might change deposition without asserting a universal sediment threshold. Locate a thalweg in a labelled bend sketch and contrast laminar, turbulent and helicoidal flow.
Cambridge 2027: Partial conceptual match
River processes and discharge: the prompt and worked answer explicitly demonstrate these selected concepts. Remaining material: g-1.2.1: cavitation and solution erosion, plus velocity/load-size evidence; g-1.2.2: measured velocity profiles and fuller flow-pattern interpretation. Fictional data are not real named-case evidence. Independent teacher review pending.
Apply Q=sum(width*depth*mean velocity). The three products are 2*0.5*0.4, 3*1*0.8 and 5*0.8*0.6; adding gives 5.2 m3/s. These rectangles and representative velocities are explicit approximations, not a real gauging record.
Trace a sand grain along the bed and a fine particle within an eddy to explain two different transport mechanisms. Contrast physical sediment with ions in solution; a clear-looking river may still carry a dissolved load.
On the bend sketch place outer-bank erosion and a displaced thalweg, with near-bed cross-channel return flow in a simplified helicoidal circulation. Velocity distribution, grain size and bank resistance all matter; the mean-discharge estimate alone does not determine erosion at every point.
Primary references (theory or real case, not sources of fictional numbers): USGS: How Streamflow is Measured; cross-sectional discharge method: https://www.usgs.gov/special-topics/water-science-school/science/how-streamflow-measured; US National Park Service: River Systems and Fluvial Landforms: https://www.nps.gov/subjects/geology/fluvial-landforms.htm
Self-marking points
View marking points
Subsection areas are 1, 3 and 4 m2 and discharges are 0.4, 2.4 and 2.4 m3/s, totalling 5.2 m3/s.
A width/depth/velocity weighting is necessary; a single near-surface or central velocity is not the cross-sectional mean.
Hydraulic action dislodges bank material through water forces; abrasion involves impacts or scraping by the transported load.
Reduced transport competence can promote deposition; clay cohesion and turbulence prevent a single speed rule for every grain.
The thalweg follows the fastest/deepest channel path, often toward an outer bend; helicoidal flow spirals, turbulence contains eddies, laminar flow has orderly layers.
Examiner tip
Discharge is a volume per time, not a velocity. Do not infer that all sediment settles as soon as a river slows. Indicative practice points only; independent teacher approval pending.
Question 2A fictional plan map describes a meandering river whose two banks at a neck are 60 m apart in Survey A and 36 m apart six years later. The outer bank is steep; a gently sloping sand bar lies inside each bend. (a) Calculate mean neck narrowing per year, state what cannot be inferred about the retreat of either bank, and draw both surveys schematically. (b) Explain outer-bank erosion, point-bar deposition and a possible flood-driven cutoff producing an oxbow. (c) Explain how overbank deposition creates a floodplain and natural levees. Distinguish this sequence from a waterfall retreating upstream to form a gorge; state why the neck trend does not predict a cutoff date.6 indicative marks
A fictional plan map describes a meandering river whose two banks at a neck are 60 m apart in Survey A and 36 m apart six years later. The outer bank is steep; a gently sloping sand bar lies inside each bend. (a) Calculate mean neck narrowing per year, state what cannot be inferred about the retreat of either bank, and draw both surveys schematically. (b) Explain outer-bank erosion, point-bar deposition and a possible flood-driven cutoff producing an oxbow. (c) Explain how overbank deposition creates a floodplain and natural levees. Distinguish this sequence from a waterfall retreating upstream to form a gorge; state why the neck trend does not predict a cutoff date.
Cambridge 2027: Partial conceptual match
Fluvial landform sequences: the prompt and worked answer explicitly demonstrate these selected concepts. Remaining material: g-1.2.3: riffle-pool sequences and bluffs, with actual map/photo interpretation rather than only a verbal schematic. Fictional data are not real named-case evidence. Independent teacher review pending.
Subtract widths measured at a consistent neck and divide by elapsed time: (60-36)/6=4 m/year. A width is a two-bank separation, so it is not evidence that each bank retreats at 2 m/year.
Draw arrows for bend migration and mark a prospective shorter channel across the neck. Explain breach, abandonment and sediment sealing as successive processes rather than treating an oxbow as simply a bend that deepens.
Link floodplain and levee deposition to a reduction in flow speed outside the channel. Contrast the horizontal bend sequence with differential erosion and collapse at a waterfall; neither progression has a fixed timetable from the two surveys.
Primary references (theory or real case, not sources of fictional numbers): US National Park Service: River Systems and Fluvial Landforms: https://www.nps.gov/subjects/geology/fluvial-landforms.htm
Self-marking points
View marking points
Neck width decreases by 24 m over six years, averaging 4 m/year; retreat cannot be allocated to individual banks from this alone.
Faster outer-bend flow can erode a river cliff while lower-energy inner-bank flow deposits a point bar.
A flood may breach the neck; subsequent deposition can isolate the abandoned bend as an oxbow lake.
Overbank flow loses competence, depositing coarser material near the channel to build levees and finer sediment farther across the floodplain.
A waterfall can undercut weaker rock, collapse a cap and retreat, leaving a gorge; this is not a meander cutoff.
An average change is not a constant-rate law; floods, engineering and bank resistance can change the trajectory.
Examiner tip
A mapped change in separation is not an individual bank's retreat rate, and a process sequence is not a reliable event forecast. Indicative practice points only; independent teacher approval pending.
Question 3Two fictional basins each receive 40 mm of rain over 10 km2. A simplified event runoff fraction is 0.25 in vegetated basin A and 0.65 in paved basin B. Ignore storage changes within the stated event calculation. A has a floodplain school; B has dense housing and an electricity substation. (a) Calculate runoff volumes and their ratio. (b) Explain how paving, antecedent saturation, rainfall intensity/duration, snowmelt and deforestation can affect flooding, distinguishing runoff volume from peak discharge. (c) Compare immediate and delayed social, economic and environmental impacts at the two sites. Evaluate why neither paving nor greater exposed asset value alone proves which basin suffers more human harm.6 indicative marks
Two fictional basins each receive 40 mm of rain over 10 km2. A simplified event runoff fraction is 0.25 in vegetated basin A and 0.65 in paved basin B. Ignore storage changes within the stated event calculation. A has a floodplain school; B has dense housing and an electricity substation. (a) Calculate runoff volumes and their ratio. (b) Explain how paving, antecedent saturation, rainfall intensity/duration, snowmelt and deforestation can affect flooding, distinguishing runoff volume from peak discharge. (c) Compare immediate and delayed social, economic and environmental impacts at the two sites. Evaluate why neither paving nor greater exposed asset value alone proves which basin suffers more human harm.
Cambridge 2027: Partial conceptual match
Flood causes and unequal impacts: the prompt and worked answer explicitly demonstrate these selected concepts. Remaining material: g-1.3.1: agricultural/irrigation changes and contrasting basin evidence; g-1.3.2: dated flood impact data and fuller duration/recovery comparisons. Fictional data are not real named-case evidence. Independent teacher review pending.
Convert 40 mm to 0.04 m and 10 km2 to 10,000,000 m2. Multiplying gives 400,000 m3; apply the two fractions separately before dividing 260,000 by 100,000.
Construct an input-storage-transfer chain for each basin. A high runoff fraction is consistent with rapid surface flow, but a peak is a rate whose timing also depends on basin shape, slope, channel routing and rainfall distribution.
Trace the substation's failure beyond the directly flooded building to households and services, then compare exposure with susceptibility and recovery capacity. These invented basins practise reasoning, not a documented recent-flood case.
Primary references (theory or real case, not sources of fictional numbers): USGS: Impervious Surfaces and Flooding: https://www.usgs.gov/water-science-school/science/impervious-surfaces-and-flooding; USGS: Streamflow and the Water Cycle: https://www.usgs.gov/water-science-school/science/streamflow-and-water-cycle
Self-marking points
View marking points
Rain volume is 400,000 m3; runoff estimates are 100,000 and 260,000 m3, a B:A ratio of 2.6.
Paving limits infiltration and connected drains can shorten travel time; saturation can increase runoff even in vegetated terrain.
Intense/prolonged rain, snowmelt and reduced interception can increase inputs or rapid runoff, conditional on basin and soil properties.
The event volumes do not supply a peak discharge or flood depth without routing and channel-capacity information.
Immediate school disruption, evacuation and electrical failure can lead to later learning loss, income loss and contamination, while flood sediment can also replenish soil.
Depth, duration, warning access, mobility, housing quality and recovery resources mediate harm; asset prices alone miss vulnerable people.
Examiner tip
Keep flood hazard, exposed assets and social vulnerability separate. An event runoff volume is not a peak flow rate. Indicative practice points only; independent teacher approval pending.
Question 4For a fictional one-hour mean surface energy budget, downward shortwave radiation is 600 W/m2, albedo is 0.25, downward longwave is 320 W/m2 and upward longwave is 400 W/m2. Outward sensible and latent heat transfers are 80 and 200 W/m2. Treat all figures as constant during the hour. (a) Calculate reflected shortwave, net radiation and the residual available for ground/storage heat. (b) Explain absorption, reflection, scattering, conduction and longwave back radiation. (c) Distinguish latent from sensible heat and explain why this local positive residual does not establish a global annual imbalance. Use a labelled energy-flow sketch and a linked causal paragraph, not a list of terms.6 indicative marks
For a fictional one-hour mean surface energy budget, downward shortwave radiation is 600 W/m2, albedo is 0.25, downward longwave is 320 W/m2 and upward longwave is 400 W/m2. Outward sensible and latent heat transfers are 80 and 200 W/m2. Treat all figures as constant during the hour. (a) Calculate reflected shortwave, net radiation and the residual available for ground/storage heat. (b) Explain absorption, reflection, scattering, conduction and longwave back radiation. (c) Distinguish latent from sensible heat and explain why this local positive residual does not establish a global annual imbalance. Use a labelled energy-flow sketch and a linked causal paragraph, not a list of terms.
Cambridge 2027: Partial conceptual match
Energy budgets and geographical explanation: the prompt and worked answer explicitly demonstrate these selected concepts. Remaining material: g-2.1.1: contrasting measured day/night and surface budgets; g-AO1: sustained knowledge across the route, spatial contexts, examples and independent teacher assessment. Fictional data are not real named-case evidence. Independent teacher review pending.
9696: AO1: Geographical knowledge and understanding
Apply albedo to incoming shortwave alone: 0.25*600=150, leaving 450 absorbed. Net all radiative fluxes with consistent signs to obtain 370 W/m2.
Subtract outward turbulent transfers: 370-80-200=90 W/m2. Multiplying by 3600 seconds gives 324,000 J/m2. The residual combines ground heat and storage in this teaching balance; it is not a measured air-temperature rise.
Use the diagram to connect the radiation pathways to matter and then separate radiative exchange from conduction and turbulent transfers. Explain that land/ocean contrasts, day-night variation and horizontal transport prevent simple global scaling.
Primary references (theory or real case, not sources of fictional numbers): NOAA: Earth-Atmosphere Energy Balance; idealised teaching budget, not current observed imbalance: https://www.noaa.gov/jetstream/atmosphere/energy
Self-marking points
View marking points
Reflected shortwave is 150 W/m2 and absorbed shortwave 450 W/m2.
Net radiation is 450+320-400=370 W/m2.
After sensible and latent transfers the residual is 90 W/m2, or 324,000 J/m2 over the hour.
Reflection redirects radiation, absorption transfers energy to matter, scattering changes directions in the atmosphere and conduction transfers heat through contact.
Atmospheric longwave back radiation contributes a downward flux; latent heat is transferred through phase change while sensible transfer changes temperature.
A local hourly budget cannot be extrapolated to a planetary annual budget; AO1 here is selected conceptual explanation only, not an assessment-wide judgement.
Examiner tip
Back radiation is not reflected sunlight. W/m2 is a flux; multiply by seconds only when an energy per area is needed. Indicative practice points only; independent teacher approval pending.
Question 5A fictional Northern Hemisphere station at 12 degrees N records 20 mm rain in January and 210 mm in July. A comparison station near 28 degrees N remains dry in both months. (a) Draw a simplified three-cell circulation section in each hemisphere with pressure belts, surface wind directions and the ITCZ. (b) Explain a plausible seasonal contrast at 12 degrees N using solar heating, migration of the convergence zone and land-sea thermal contrast. (c) Explain the subtropical dryness and why these two rainfall totals do not prove the circulation mechanism or describe every place at these latitudes. State one observation that could challenge your explanation.6 indicative marks
A fictional Northern Hemisphere station at 12 degrees N records 20 mm rain in January and 210 mm in July. A comparison station near 28 degrees N remains dry in both months. (a) Draw a simplified three-cell circulation section in each hemisphere with pressure belts, surface wind directions and the ITCZ. (b) Explain a plausible seasonal contrast at 12 degrees N using solar heating, migration of the convergence zone and land-sea thermal contrast. (c) Explain the subtropical dryness and why these two rainfall totals do not prove the circulation mechanism or describe every place at these latitudes. State one observation that could challenge your explanation.
Cambridge 2027: Partial conceptual match
Circulation and seasonal climates: the prompt and worked answer explicitly demonstrate these selected concepts. Remaining material: g-2.1.3: pressure-gradient/Coriolis/jet-stream detail and ocean heat transfers; g-2.1.4: full annual climate graphs and documented contrasting seasonal settings. Fictional data are not real named-case evidence. Independent teacher review pending.
First label broad low and high pressure zones on an idealised latitude section, then connect winds and vertical motions. The three-cell drawing is an average model, not a literal closed conveyor at every longitude.
Trace heating to pressure, convergence, uplift, cooling and possible condensation. The July-January difference is 190 mm, but the two months alone do not identify an annual rainy season or its cause.
Compare the expected pressure/wind changes with a proposed observation: persistent descending air and offshore dry winds in July would weaken the ITCZ explanation. Distinguish a physically plausible account from a demonstrated causal attribution.
Primary references (theory or real case, not sources of fictional numbers): NOAA: Global Atmospheric Circulations: https://www.noaa.gov/jetstream/global/global-atmospheric-circulations
Self-marking points
View marking points
Show Hadley, Ferrel and Polar cells with ascent near the equatorial convergence zone and descent in subtropical highs.
Northern trade winds are generally north-easterly and southern trades south-easterly; rotation deflects moving air rather than creating the pressure gradient.
A northward seasonal convergence shift can favour July ascent and rain at the fictional 12-degree-N station.
Differential heating of land and sea can strengthen seasonal pressure contrasts and monsoonal wind changes.
Descending subtropical air warms and inhibits condensation; nearby cold currents or continentality may reinforce dryness.
Observed winds, pressure and moisture profiles are needed; mountains, sea temperatures and interannual variability can contradict a latitude-only explanation.
Examiner tip
The ITCZ moves seasonally, but rainfall is not controlled by latitude alone. Coriolis changes direction, not the initial heating contrast. Indicative practice points only; independent teacher approval pending.
Question 6Three fictional observations are supplied: A has a hot land surface and afternoon rising towers of cloud; B has moist air forced over a mountain and a drier lee slope; C has a warm moist air mass rising over denser colder air. (a) Identify and draw the uplift mechanism for each. (b) Explain cooling, saturation, condensation nuclei and droplet/ice growth in producing precipitation, rather than saying clouds simply become full. (c) If a 100 cm2 rain-gauge opening collects 180 cm3, calculate rainfall depth and explain two reasons one gauge cannot establish the mountain's precipitation pattern.5 indicative marks
Three fictional observations are supplied: A has a hot land surface and afternoon rising towers of cloud; B has moist air forced over a mountain and a drier lee slope; C has a warm moist air mass rising over denser colder air. (a) Identify and draw the uplift mechanism for each. (b) Explain cooling, saturation, condensation nuclei and droplet/ice growth in producing precipitation, rather than saying clouds simply become full. (c) If a 100 cm2 rain-gauge opening collects 180 cm3, calculate rainfall depth and explain two reasons one gauge cannot establish the mountain's precipitation pattern.
Cambridge 2027: Partial conceptual match
Precipitation processes: the prompt and worked answer explicitly demonstrate these selected concepts. Remaining material: g-2.2.3: actual event resources, precipitation forms and development under differing atmospheric stability and moisture conditions. Fictional data are not real named-case evidence. Independent teacher review pending.
Match the physical driver, not just the cloud appearance: surface heating, topographic obstruction and density contrasts give different uplift geometries. Sketch windward ascent and lee descent for the mountain case.
Connect expansion to cooling and saturation, then separate cloud-droplet formation from precipitation growth. Different mechanisms can occur together; these simplified descriptions do not establish that every event belongs exclusively to one type.
Divide 180 cm3 by 100 cm2 to obtain 1.8 cm. Compare repeated windward and lee gauges at known elevations, with consistent times and siting, before claiming a rain shadow from measurements.
Primary references (theory or real case, not sources of fictional numbers): NOAA: Precipitation; measurement and spatial variability: https://www.noaa.gov/jetstream/atmosphere/precipitation; NOAA: Global Atmospheric Circulations: https://www.noaa.gov/jetstream/global/global-atmospheric-circulations
Self-marking points
View marking points
A is convectional uplift, B orographic uplift and C frontal uplift; diagrams must show the appropriate air motion.
Rising air expands and cools; reaching saturation allows condensation on suitable nuclei, followed by growth of droplets or ice particles.
Raindrops must grow sufficiently to fall relative to updraughts; saturation does not imply that every cloud rains.
Depth=volume/area=1.8 cm=18 mm.
Wind exposure, gauge siting, precipitation type and spatial/altitudinal variability can bias a single observation.
Examiner tip
Cloud formation and precipitation are not the same step. A collected volume becomes rainfall depth only after division by gauge area. Indicative practice points only; independent teacher approval pending.
Question 7The IPCC AR6 Synthesis Report (2023) reports global surface temperature in 2011-2020 at 1.1 degrees C above 1850-1900. This is a real assessment statistic, not a reading for one city or one year. A separate fictional station has ten-year means of 13.2 and 14.0 degrees C. (a) Calculate its change and explain why it cannot simply replace the IPCC estimate. (b) Compare instrumental thermometers, ice-core gases/isotopes, tree rings and glacial evidence as records of climatic change. (c) Design an evidence-based response to the claim that one cold winter disproves long-term warming, including spatial averaging, baselines, proxy calibration and uncertainty.6 indicative marks
The IPCC AR6 Synthesis Report (2023) reports global surface temperature in 2011-2020 at 1.1 degrees C above 1850-1900. This is a real assessment statistic, not a reading for one city or one year. A separate fictional station has ten-year means of 13.2 and 14.0 degrees C. (a) Calculate its change and explain why it cannot simply replace the IPCC estimate. (b) Compare instrumental thermometers, ice-core gases/isotopes, tree rings and glacial evidence as records of climatic change. (c) Design an evidence-based response to the claim that one cold winter disproves long-term warming, including spatial averaging, baselines, proxy calibration and uncertainty.
Cambridge 2027: Partial conceptual match
Climate evidence and baselines: the prompt and worked answer explicitly demonstrate these selected concepts. Remaining material: g-2.3.1: actual proxy/instrumental graphs, dating scales and cross-archive comparisons across the required time spans. Fictional data are not real named-case evidence. Independent teacher review pending.
Compute 14.0-13.2=0.8 degrees C and keep its fictional place, period and baseline attached. The IPCC figure compares two different stated periods at a global scale; arithmetic agreement is neither required nor a validation method.
For each archive identify what is observed and what is inferred. Trapped gases and isotope ratios answer different questions; no tree ring is a direct global thermometer.
Evaluate the cold-winter claim with a distribution of weather around changing long-term conditions. Propose matched baselines and multiple lines of evidence, not a claim that uncertainty means no warming or that every local year must be warmer.
Primary references (theory or real case, not sources of fictional numbers): IPCC AR6 Synthesis Report 2023, SPM A.1/A.2/B.2; 2011-2020 warming relative to 1850-1900: https://www.ipcc.ch/report/ar6/syr/summary-for-policymakers/
Self-marking points
View marking points
The fictional station change is 0.8 degrees C, not a global anomaly on the IPCC baseline.
Instrumental records provide direct measurements but require consistent siting, homogenisation and spatial coverage.
Ice cores can preserve atmospheric gases and temperature-related isotope signals; tree rings are locally sensitive proxies requiring calibration.
Glacial extent provides another climate-related indicator but can respond with lags and local controls.
A winter is weather within a variable climate; compare longer spatially representative records rather than selecting a single anomaly.
Converging independent records strengthen inference while dating, coverage and calibration uncertainties remain.
Examiner tip
A temperature anomaly needs a place, time window and baseline. Do not compare a local ten-year change directly with a global pre-industrial anomaly. Indicative practice points only; independent teacher approval pending.
Question 8A fictional spreading ridge has basalt dated at 2 million years at positions 50 km on each side of its axis. Treat the axis as stationary and spreading as symmetric. (a) Calculate each half-spreading rate and the full separation rate in cm/year. (b) Distinguish lithosphere from crust and asthenosphere, and compare typical oceanic and continental crust in thickness, density and composition without claiming uniform values. (c) Explain how symmetric magnetic stripes, increasing seafloor age and modern satellite geodesy independently support motion. Assess slab pull, ridge-related gravitational forces and mantle motion without calling the mantle an ocean of liquid magma.6 indicative marks
A fictional spreading ridge has basalt dated at 2 million years at positions 50 km on each side of its axis. Treat the axis as stationary and spreading as symmetric. (a) Calculate each half-spreading rate and the full separation rate in cm/year. (b) Distinguish lithosphere from crust and asthenosphere, and compare typical oceanic and continental crust in thickness, density and composition without claiming uniform values. (c) Explain how symmetric magnetic stripes, increasing seafloor age and modern satellite geodesy independently support motion. Assess slab pull, ridge-related gravitational forces and mantle motion without calling the mantle an ocean of liquid magma.
Cambridge 2027: Partial conceptual match
Plate characteristics and motion evidence: the prompt and worked answer explicitly demonstrate these selected concepts. Remaining material: g-3.1.1: fuller Earth structure and physical contrasts; g-3.1.2: actual magnetic/geodetic resources and fuller evaluation of driving mechanisms. Fictional data are not real named-case evidence. Independent teacher review pending.
50 km is 5,000,000 cm; dividing by 2,000,000 years gives 2.5 cm/year on each side. Two opposite velocities give a separation rate of 5, not 2.5 cm/year.
Use a labelled cross-section to separate compositional boundaries from mechanical layers. A plate is not merely a piece of crust floating on a fully molten layer.
Link each evidence type to a distinct timescale and measurement. Distinguish the magnetic record of cooling basalt from direct modern position measurements; agreement strengthens the interpretation but does not demonstrate perfectly steady motion.
Primary references (theory or real case, not sources of fictional numbers): USGS This Dynamic Earth: Understanding plate motions; use mechanisms, not its historical satellite inventory: https://pubs.usgs.gov/gip/dynamic/understanding.html
Self-marking points
View marking points
Each half rate is 2.5 cm/year; full separation is 5 cm/year under the stated symmetric model.
Lithosphere includes crust and rigid uppermost mantle; the asthenosphere is weaker/deformable but predominantly solid.
Oceanic crust is typically thinner, denser and more basaltic; continental crust is more compositionally varied and generally thicker and less dense.
Matching reversal patterns and older crust away from a ridge support seafloor production and outward motion.
Repeated geodetic positions measure present movement; their short observation period differs from geological averages.
Plate motion involves coupled gravitational and mantle processes; evidence for motion alone does not assign exact shares to each driving force.
Examiner tip
Half-spreading and full separation rates differ by a factor of two only under the explicitly symmetric model. Indicative practice points only; independent teacher approval pending.
Question 9A fictional hazard map shows A with shallow earthquakes and linear basaltic volcanism; B with an ocean trench, a volcanic arc and earthquake depths increasing inland; C with a linear shallow-earthquake belt but little associated volcanism. (a) Infer a likely boundary type for each and draw labelled cross-sections. (b) Explain why subduction, divergence and transform motion produce different earthquake depths and volcanic patterns. (c) Use the real Mid-Atlantic Ridge/Iceland, Andes and San Andreas examples described by USGS to test the interpretations, then explain why not all volcanoes or earthquakes lie at plate boundaries. State why this pattern exercise cannot predict an eruption date or magnitude.6 indicative marks
A fictional hazard map shows A with shallow earthquakes and linear basaltic volcanism; B with an ocean trench, a volcanic arc and earthquake depths increasing inland; C with a linear shallow-earthquake belt but little associated volcanism. (a) Infer a likely boundary type for each and draw labelled cross-sections. (b) Explain why subduction, divergence and transform motion produce different earthquake depths and volcanic patterns. (c) Use the real Mid-Atlantic Ridge/Iceland, Andes and San Andreas examples described by USGS to test the interpretations, then explain why not all volcanoes or earthquakes lie at plate boundaries. State why this pattern exercise cannot predict an eruption date or magnitude.
Cambridge 2027: Partial conceptual match
Plate boundaries and hazard distributions: the prompt and worked answer explicitly demonstrate these selected concepts. Remaining material: g-3.1.3: collision and ocean-ocean boundary detail with actual maps; g-9.1.1: global distribution resources, hotspot exceptions and comparative event catalogues. Fictional data are not real named-case evidence. Independent teacher review pending.
Match each combination of landform, event depth and volcanism, then mark direction arrows and the descending slab where appropriate. Continental collision should be distinguished from an oceanic slab descending beneath a continent.
Use the USGS named settings as real geographical anchors, not as the origin of the invented A/B/C observations. The Andes do not imply the continental crust simply melts wholesale because of friction.
Test a boundary-only explanation against an intraplate volcano or earthquake. Identifying a spatial pattern supports a mechanism but supplies neither recurrence intervals nor an exact future event size.
Primary references (theory or real case, not sources of fictional numbers): USGS This Dynamic Earth: Understanding plate motions; use mechanisms, not its historical satellite inventory: https://pubs.usgs.gov/gip/dynamic/understanding.html
Self-marking points
View marking points
A is consistent with divergence, B with subduction and C with a transform boundary; the observations suggest rather than uniquely prove these settings.
Decompression can generate melt at divergence; fluids from a descending slab promote melting in the mantle wedge at subduction.
Earthquakes can deepen along a descending slab; transform faulting mainly produces shallow earthquakes without a systematic volcanic arc.
Iceland occupies the Mid-Atlantic spreading region; Nazca-South America convergence relates to the Andes; San Andreas is a transform setting.
Intraplate hotspots and reactivated faults show that boundary belts do not explain every event; continental collision is a further convergent setting.
Distribution is not an event forecast; hazard depends on processes, exposure, vulnerability and monitoring as well as map proximity.
Examiner tip
Volcanoes and earthquakes have overlapping but different distributions. A transform earthquake belt does not imply a volcanic arc. Indicative practice points only; independent teacher approval pending.
Question 10Fictional slope evidence includes A: individual blocks falling from a cliff; B: a coherent soil mass with a curved slip surface and backward-tilted trees; C: a saturated mixture moving through a channel; D: slowly displaced soil and progressively leaning fence posts. (a) Identify the movement forms and sketch their geometries. (b) Explain how rainfall, pore-water pressure, undercutting and vegetation removal can alter the force-strength balance. (c) At D a marker moves 18 mm downslope over three years. Calculate its average movement rate and explain why that rate cannot forecast the speed of a future rapid failure or by itself establish the cause.5 indicative marks
Fictional slope evidence includes A: individual blocks falling from a cliff; B: a coherent soil mass with a curved slip surface and backward-tilted trees; C: a saturated mixture moving through a channel; D: slowly displaced soil and progressively leaning fence posts. (a) Identify the movement forms and sketch their geometries. (b) Explain how rainfall, pore-water pressure, undercutting and vegetation removal can alter the force-strength balance. (c) At D a marker moves 18 mm downslope over three years. Calculate its average movement rate and explain why that rate cannot forecast the speed of a future rapid failure or by itself establish the cause.
Cambridge 2027: Partial conceptual match
Mass movement forms and evidence: the prompt and worked answer explicitly demonstrate these selected concepts. Remaining material: g-3.3.1: translational slides, additional slow-flow forms and comparative slope resources across materials and climates. Fictional data are not real named-case evidence. Independent teacher review pending.
Classify by material and motion rather than calling every downslope change a mudslide. Mark a curved rupture surface for B and internal deformation within a channelised mixture for C.
Explain separately an increase in driving stress and a decrease in resisting strength. Added water can change weight and pore pressure; a dry-looking surface does not prove that the potential slip plane is dry.
Compute 18/3=6 mm/year for the specific marker and interval. Compare repeat surveys with groundwater and rainfall records; an averaged displacement cannot establish either a trigger or the instantaneous speed of another movement type.
Primary references (theory or real case, not sources of fictional numbers): USGS Fact Sheet 2004-3072: Landslide Types and Processes: https://pubs.usgs.gov/fs/2004/3072/fs-2004-3072.html
Self-marking points
View marking points
Identify rockfall, rotational slide/slump, debris flow and soil creep respectively, with distinct movement paths.
Gravity drives downslope movement; saturated pore spaces can reduce effective stress and shear resistance.
Undercutting can remove toe support and vegetation removal can reduce reinforcement; rainfall is not the only possible trigger.
Average recorded movement is 6 mm/year, not evidence that every year or every point moved equally.
Slow creep and rapid failure differ in mechanism and timescale; a cause requires rainfall, geology, drainage and repeated deformation evidence.
Examiner tip
A rotational slide has a recognisable slip surface; a flow deforms internally. Do not transfer one marker's average creep rate to a debris flow. Indicative practice points only; independent teacher approval pending.
