Canary Islands PAU Geology & Env Sci common mistakes
Canary Islands PAU Geology & Env Sci · Understand the traps and how to avoid them.
On plate-tectonics questions, describing the Canary Islands as sitting on a constructive (divergent) plate boundary and explaining volcanism as sea-floor spreading, instead of placing them on the African plate over a hotspot/weak zone in an intraplate setting.
The archipelago is volcanic and students transfer the 'volcanoes = plate boundary' template from textbook examples like Iceland or the Andes, without checking the actual tectonic setting of the eastern Atlantic margin.
What to do instead
Before answering any Canary volcanism question, state the setting explicitly: intraplate, African plate, passive continental margin, hotspot/alkaline magmatism. Then tie each feature (alkaline basalts, absence of andesitic arc rocks, no deep trench, no Benioff zone) back to that setting as evidence.
Confusing the three main rock classes when identifying hand specimens, for example calling a coarse-grained granite 'metamorphic because it looks crystalline', or labelling an foliated gneiss as 'sedimentary banding'.
Candidates memorise rock names from photos but never learn the diagnostic criteria (grain size, mineral assemblage, foliation, bedding, clasts, reaction to acid), so they classify by colour and overall appearance.
What to do instead
Use a fixed decision routine on every unknown rock: (1) is it crystalline or clastic? (2) grain size and mineralogy, (3) fabric - bedding vs foliation vs massive, (4) any fossils or clasts. Practise by writing the routine out and applying it to at least ten specimens, giving the reason for each rejection, not just the final name.
Treating geological time qualitatively - saying 'millions of years' without ordering events or converting units - and failing to place the main Canary volcanic phases or the Quaternary glaciations on a numerical timeline.
The geological time scale is studied as a list of names to memorise, so candidates cannot use it as a tool for relative dating, and they mix up Ma (mega-annum) with ka and with 'millions of years ago' vs 'duration'.
What to do instead
Build one annotated timeline from 4,600 Ma to present with the events you must know (Earth formation, first life, Cambrian explosion, P–T extinction, K–Pg extinction, first hominins, Canary island subaerial volcanism, last glacial maximum). Practise stating both the age and the duration of each event and converting Ma to years in your head.
Confusing weathering with erosion and transport, for example writing that 'water weathers the rock down the slope' or listing deposition as a stage of weathering.
Everyday language uses 'erosion' for the whole process, and textbooks present the external cycle as a single flow, so the boundaries between disintegration, removal, transport and deposition blur.
What to do instead
For any landscape or landform question, force yourself to name the process at each step: disintegration in situ (physical/chemical/biological weathering), entrainment and removal (erosion), movement by a specified agent (transport), and settling (deposition). Write one sentence per stage for a named Canary example such as a barranco or a lava slope.
Answering hazard questions by describing the phenomenon (what a lahar or a pyroclastic flow is) but omitting the risk equation - hazard, exposure, vulnerability - and therefore never proposing a mitigation measure or explaining why one works.
Candidates prepare definitions and diagrams, and hazard, risk and vulnerability are used interchangeably in the syllabus, so the analytical part of the question goes unanswered even when the description is correct.
What to do instead
Adopt a fixed three-part answer for every hazard question: (1) the physical process and its triggers, (2) who and what is exposed and why they are vulnerable, (3) a specific mitigation measure (monitoring network, land-use zoning, evacuation plan, building code) with the mechanism by which it reduces loss. Always separate hazard from risk in your first sentence.
On map and cross-section questions, drawing a cross-section without a vertical scale and with beds at the wrong dip direction, or reading a contour/structural symbol without checking the legend and north arrow first.
Candidates rush to draw and treat the cross-section as an illustration rather than a construction, and they skip the legend because they assume the symbols are standard.
What to do instead
Follow a rigid construction order: north arrow and legend, then the line of section, then plot topography from contours, then project each boundary at its true dip and apparent dip, then add a vertical scale and label it. Check the dip direction against the strike symbol before drawing. Do this on three past-style maps until it becomes automatic.
Explaining the Canary climate with generic global statements ('it is hot because it is near the equator' or 'it rains in winter') without invoking the Azores anticyclone, the trade winds, the Canary Current and the temperature inversion, or without distinguishing windward from leeward islands.
The global atmospheric circulation model is learned in the abstract, and candidates do not connect the subtropical high and cold upwelling to the observed aridity, the 'sea of clouds' and the altitudinal belts on the islands.
What to do instead
Draw a labelled east–west atmospheric section across the archipelago at about 28°N showing the Azores high, subsidence, trade-wind inversion at roughly 1,000–1,500 m, the Canary Current and upwelling. Then explain three concrete consequences: coastal desert, cloud belt with laurel forest on north-facing slopes, and leeward aridity. Use this diagram for every Canary climate question.
Describing ocean dynamics by naming currents and tides without explaining the driving mechanisms, and mixing up the Canary Current's direction and its effect on coastal water temperature and productivity.
Currents and tides are memorised as facts on a map rather than as responses to wind stress, Coriolis deflection, density gradients and gravitational forcing, so direction and consequences are easily reversed.
What to do instead
For each current or process, state the driver, the direction and the consequence. For the Canary Current: driven by trade winds and the subtropical gyre, flows south-west along the African coast, carries cool water, promotes upwelling, raises nutrient supply and productivity, and moderates coastal temperatures. Rehearse the same three-part pattern for tides, waves and upwelling.
Treating soil as inert 'dirt' - describing soil formation as a single process and ignoring the parent material, climate, relief, organisms and time factors - and failing to link island soil types and their vulnerability to erosion and salinisation.
Soils are covered briefly in the syllabus and are often revised last, so candidates have no framework for explaining why island soils are thin, why terraces and volcanic ash soils matter, or why deforestation increases erosion.
What to do instead
Learn the five soil-forming factors as a checklist and apply them to a named Canary soil (for example the volcanic andisols or the aridisols of the lowlands). For each soil, state its profile, its fertility, and one threat (water erosion on steep slopes, salinisation from irrigation, loss of organic matter).
Answering environmental-impact and waste questions with moral generalities ('we must recycle more', 'pollution is bad') instead of naming the pollutant, its source, its pathway, its effect on a specific receptor, and a concrete management measure.
These questions invite opinion, and candidates confuse expressing concern with demonstrating environmental science, so they never use the source–pathway–receptor model or the waste hierarchy.
What to do instead
Answer impact questions in a fixed chain: activity, pollutant or pressure, environmental compartment, effect on a named receptor, and management measure ranked by the waste hierarchy (prevention, reuse, recycling, recovery, disposal). For Canary contexts, name a real pressure such as desalination brine discharge, tourism water demand, or landfill siting on volcanic terrain, and the specific measure that addresses it.