πŸ”Ά Part 1 β€” Tutorial & Strategy

How to Master Matching Headings for β€œVolcanoes: Causes and Effects”

Goal: Select the heading that captures the main idea of each paragraph (A, B, C, …). Ignore shiny details like dates, proper nouns, or dramatic examples. Focus on function and emphasis.

Everything below is written to sit neatly in this frame. On phones, text reflows, touch areas stay large, and all boxes stack vertically.

Step 1 β€” Preview the Heading List to Build a Mental Map (10–20 sentences)

Before reading the passage, scan all headings once to predict the logical β€œrooms” the text might contain. Look for function words that signal structure, such as cause, effect, contrast, process, sequence, evaluation, or solution. Group similar headings so you can tell apart near twins later (e.g., β€œImmediate hazards of ash” vs. β€œLong-term climatic effects”). Notice scope: some headings are broad (β€œDrivers of volcanic activity”), others very narrow (β€œThe role of water in explosive eruptions”). Expect broad headings to match synthesising paragraphs and narrow ones to match focused analyses. Do not chase words; IELTS writers often paraphrase. Instead, ask what function each heading describesβ€”definition, mechanism, chronology, comparison, or recommendation. Anticipate common volcano themes: plate boundaries, mantle plumes, magma viscosity, degassing, hazards (tephra, ash, pyroclastic flows, lahars), monitoring, and risk management. Mark any headings that hint at evaluation (e.g., β€œweighing costs and benefits”), because evaluative paragraphs often appear near conclusions. Decide your work plan: scan headings β†’ skim paragraph β†’ draft a gist line β†’ shortlist two headings β†’ confirm with topic/concluding lines. This preview gives you a compass so you read for structure, not for isolated terms. It reduces decision fatigue later and keeps you calm under time pressure. Treat the headings as labels for room purposes, not word lists to β€œfind.” When you finally read, you will notice the right signals quickly and skip traps confidently.

Step 2 β€” Skim Each Paragraph for Gist, Not Details (10–20 sentences)

Read paragraph A briskly to capture the overall message; do not stop for every technical term unless it blocks meaning. Pay special attention to the first and last sentences, because they often set scope and deliver emphasis. Look for structure signals: however, yet, by contrast for contrast; therefore, consequently, as a result for cause–effect; first, next, finally for process. In volcano texts, separate examples (e.g., β€œPinatubo 1991”) from the point (e.g., β€œsulfur aerosols cool climate”). Ask yourself: β€œIf I wrote a sign on this paragraph’s door, what would it say in 7–10 words?” Write a tiny gist like β€œWater content drives explosivity via rapid gas expansion.” Do not let dramatic detailsβ€”fatality counts, town names, datesβ€”pull you away from the thesis. If the paragraph opens with background and ends with a pivot (e.g., β€œYet viscosity, not volume, best predicts explosivity”), the pivot is likely the core. If you are lost, paraphrase one plain sentence: β€œThis paragraph says [X] happens because [Y], which leads to [Z].” Keep momentum: the first pass is about the map, not perfection. Gist skimming is your shield against synonym traps and detail magnets.

Step 3 β€” Match by Function: Definition, Process, Cause–Effect, Contrast, Evaluation (10–20 sentences)

Classify the paragraph’s function before matching a heading. If it defines or describes (e.g., β€œShield vs. stratovolcano shapes and materials”), choose a descriptive heading. If it explains why (e.g., β€œGas expansion in viscous magma drives fragmentation”), choose a cause–effect heading. If it shows stages (e.g., β€œFrom magma ascent to eruption column to fallout”), choose a process/chronology heading. If it weighs pros and cons (e.g., β€œBenefits of ash to soils versus impacts on aviation”), choose an evaluation heading. For contrast (e.g., β€œSubduction-zone eruptions versus hotspot eruptions”), prefer headings that include signals like β€œcompared with,” β€œwhereas,” or β€œa shift.” When a paragraph offers a solution or strategy (e.g., β€œEvacuation protocols and probabilistic forecasts”), match it to management/response headings. Ensure the heading covers the whole paragraph; partial fits are red flags. When two headings are similar, ask which one captures the paragraph’s emphasis, not just its topic. This function-first habit neutralises paraphrase tricks such as β€œthickness” for β€œviscosity,” β€œfine particles” for β€œash,” or β€œslope failure” for β€œlahar initiation.” Your matches become robust even when wording changes.

Step 4 β€” Shortlist Two, Test Against Emphasis, Then Commit (10–20 sentences)

For each paragraph, shortlist two plausible headings and test them against the topic and concluding lines. Ask, β€œDoes every sentence make sense under this heading, or do some feel orphaned?” Eliminate the heading that cannot explain the ending emphasis. If both seem possible, hunt for a unique signal: a causal link, a contrast pivot, or a time sequence that only one heading predicts. Cross off used headings to simplify later decisions. Keep a tiny grid: A–H with your first choice and a β€œ?” if unsure. After finishing all paragraphs, revisit the β€œ?” items; later context often clarifies earlier ambiguity. If time runs low, commit to your best evidence-based choice rather than leaving blanks. Remember that IELTS sets usually spread heading types; eight paragraphs rarely all take β€œcause–effect.” When you change a choice, ask whether your old pick now fits a different paragraph betterβ€”this chain reaction often resolves the last two items. Confidence comes from coherence: the correct heading makes the paragraph feel organised and inevitable.

Step 5 β€” Disarm Traps with Volcano-Specific Examples (10–20 sentences)

Trap 1: Word-match illusion. A heading says β€œash fall,” the paragraph’s thrust is actually β€œaviation risk management”—match function, not the loud noun. Trap 2: Example magnet. A vivid eruption (e.g., β€œEyjafjallajΓΆkull”) tempts you, but it only illustrates the general claimβ€”choose the heading naming the claim. Trap 3: Background decoy. A paragraph opens with plate tectonics history but ends by asserting β€œwater content is decisive”; pick the heading about water, not tectonics. Trap 4: Scope mismatch. β€œRegional climate effects” is broader than a paragraph on β€œstratospheric sulfur aerosols after one eruption.” Trap 5: Synonym shuffle. β€œViscosity” ↔ β€œthickness,” β€œgas exsolution” ↔ β€œbubble formation,” β€œdebris flow” ↔ β€œlahar.” Trap 6: Proper-noun distraction. Place names, years, and magnitudes are evidence, not essence. Trap 7: Double-contrast. A paragraph contrasts shield vs. stratovolcanoes but concludes that gas content dominates; the heading should reflect the winning emphasis. When stuck, reduce the paragraph to a 10-word paraphrase and match that to the best function-labelled heading.

Step 6 β€” Pace, Review, and Final Checks (10–20 sentences)

Set a strict time budget per set and protect it. On your first pass, bank the β€œobvious” matches to buy time later. Afterward, scan unused headings; sometimes one screams the identity of a stubborn paragraph. Re-read the last sentence of any doubtful paragraphβ€”writers often park the core claim there. Ensure distribution looks plausible across types (e.g., a balance of process, cause–effect, contrast, evaluation). Confirm you have not assigned a very specific heading to two different paragraphs. If you replace a heading, quickly re-validate earlier paragraphs that depended on it. Keep micro-decisions moving to avoid cognitive drain. In the final minute, answer every itemβ€”educated guesses beat blanks. Breathe, reset, and move on; method, not memory, wins Matching Headings.

Example Box 1 β€” Cause–Effect Focus

Paragraph gist: β€œHigh dissolved water in magma leads to rapid gas expansion, which shatters melt into ash.”

Correct heading type: Cause–effect (β€œWater content drives explosivity”), not a simple hazard list.

Why: The paragraph explains a mechanism, not merely names dangers.

Example Box 2 β€” Topic vs. Example

Paragraph gist: β€œThe 1991 Pinatubo eruption illustrates how sulfur aerosols cool global climate for years.”

Correct heading type: Long-term climatic effects, not β€œA famous eruption.”

Why: Pinatubo is evidence for the broader climatic mechanism.

Example Box 3 β€” Contrast Emphasis

Paragraph gist: β€œHotspot shield volcanoes produce fluid lavas, whereas subduction zones yield viscous, explosive magmas.”

Correct heading type: Contrast (β€œDifferent tectonic settings, different eruption styles”).

Why: The pivot word β€œwhereas” signals the paragraph’s structural heart.

Example Box 4 β€” Chronology/Process

Paragraph gist: β€œFrom magma ascent to vent opening to eruption column and ash fallout, eruptions follow stages.”

Correct heading type: Sequence/process (β€œThe stages of an eruption”).

Why: Time markers and ordered phases dominate.

Example Box 5 β€” Scope Check

Paragraph gist: β€œAsh fertilises soils but disrupts aviation and power networks.”

Correct heading type: Evaluation/trade-off (β€œBenefits and costs of ash”), not β€œAsh and lahars worldwide.”

Why: The paragraph weighs outcomes and prioritises impacts.

Example Box 6 β€” Synonym Trap

Paragraph gist: β€œViscous magma traps gas, increasing pressure.”

Correct heading words: β€œthick,” β€œsticky,” or β€œhigh-silica magma,” not necessarily β€œviscous.”

Why: IELTS paraphrases; match meaning, not exact wording.

Universal β€œFill-in-the-Gap” Answer Template (Sentence-by-Sentence)

Use these ready-made lines to justify each match. Replace brackets with your notes.

  1. Identification: β€œFor Paragraph [__], I propose Heading [__] because the paragraph’s main function is [description / cause–effect / contrast / process / evaluation / solution].”
  2. Topic Focus: β€œThe topic sentence presents [core subject], framing the discussion around [central idea].”
  3. Signal Words: β€œMarkers such as [however / therefore / initially / whereas] indicate a [contrast / consequence / sequence] structure.”
  4. Evidence Role: β€œExamples like [eruption/case] serve to [illustrate / support] the main claim rather than define it.”
  5. Emphasis Check: β€œThe concluding line stresses [key outcome/pivot], aligning with the heading’s focus on [phrase].”
  6. Scope Match: β€œThe heading’s scope [precisely matches] the paragraph; it neither ignores [important sub-point] nor exceeds boundaries.”
  7. Function Match: β€œBecause the paragraph primarily [explains / contrasts / sequences / evaluates], a heading about [function keyword] is stronger than [near-miss heading].”
  8. Trap Avoidance: β€œAlthough it mentions [distracting detail/word], this is supporting detail; the main idea is [restate gist].”
  9. Synonym Awareness: β€œThe paragraph’s term [term] corresponds to the heading’s phrase [paraphrase], confirming meaning.”
  10. Final Justification: β€œTherefore, Heading [__] best summarises Paragraph [__] by capturing its [dominant idea/function].”
One-Line Answer Pattern (for your sheet)

Paragraph [__] β†’ Heading [__]: [function] β€” topic: [subject]; emphasis: [key point]; signals: [markers]; reject: [near-miss].

Quick Warm-Up (Apply the Template)

Micro-paragraph: β€œDespite dramatic lava fountains, the eruption’s greatest disruption came from ash in the upper winds, grounding flights for days.”

Choose: A) β€œSpectacular lava displays” β€’ B) β€œTiny particles with outsized impacts” β€’ C) β€œHow tectonic plates move”

Model justification (condensed): Function = evaluation of impact; emphasis = aviation disruption by ash; best heading = B.

πŸ”· Part 2 β€” Reading Passage + Questions

Task: Match the Headings to Paragraphs A–H

Read the passage and choose the heading that best captures the main idea of each paragraph. There are more headings than paragraphs. Focus on function and emphasis, not on repeated words.

⏳ Countdown Timer
00:15:00

Tip: Set a budget (e.g., 15 minutes). Skim once for gist, then match by function.

List of Headings

Choose from the following headings (i–xv). Some headings will not be used.

  1. Drivers of magma formation beneath the crust
  2. How dissolved gases control the violence of eruptions
  3. The misleading appeal of dramatic lava flows
  4. Why water matters at subduction zones
  5. Contrasting eruption styles across tectonic settings
  6. The sequence from magma ascent to ash fallout
  7. Close-range hazards and how they harm communities
  8. When volcanic debris mixes with water
  9. The far-reaching effects of fine ash on technology
  10. Volcanoes and temporary shifts in global climate
  11. Balancing benefits and costs of volcanic materials
  12. From detection to decision: modern monitoring
  13. Why examples do not equal the main idea
  14. Uncertainties that make evacuation complex
  15. Long eruptions versus short ones: what really matters
Reading Passage β€” Volcanoes: Causes and Effects
A

Most volcanoes owe their existence to the slow but relentless motions of Earth’s outer shell. Where plates diverge, hot mantle rises and partially melts, feeding gentle volcanic activity along oceanic ridges and rift zones. Elsewhere, plumes of anomalously hot rock ascend like conveyor belts from deep within the mantle, creating island chains as plates drift overhead. Yet the most explosive volcanoes usually sit where one plate descends beneath another: a wet slab is pulled into the mantle, releasing fluids that lower the melting point of the overlying rocks. Although the surface geography varies, the underlying drivers are remarkably systematicβ€”pressure release, heat transfer, and, crucially, the addition of volatiles that trigger melting at depths that would otherwise remain solid.

B

The chemistry and texture of magma govern whether a volcano whispers or roars. Magma rich in silica is β€œthick,” resisting flow and trapping gas bubbles as they grow. With nowhere to escape, pressure builds until the melt shatters, fragmenting into ash and pumice that surge upward. In contrast, fluid, basaltic magma allows gases to percolate out quietly; the result is usually a fountain or flow rather than a detonation. These physical propertiesβ€”viscosity, crystal content, and temperatureβ€”set the stage, but it is the dissolved gas itself, especially water, that loads the spring. When exsolution happens abruptly, a calm conduit can become a cannon.

C

Subduction zones are special because the downgoing plate is not just rock; it is a cargo of water locked in minerals and sediments. As the slab sinks and heats, these minerals break down, releasing fluids into the mantle wedge above. Water acts as an antifreeze for rocks, lowering their melting point and generating magmas that are sticky and gas-rich. The combination is potent: viscous magmas climb slowly, degas inefficiently, and often erupt explosively. Thus, a seemingly minor ingredientβ€”waterβ€”helps explain why volcanic arcs from the Andes to the Pacific Northwest have a reputation for drama out of proportion to their size.

D

Eruptions often unfold as a chain of linked stages rather than a single burst. Magma ascends and accumulates, fractures open a pathway, gases separate and expand, and the mixture accelerates toward the surface. A towering eruption column may form, followed by the fallout of ash across wide areas downwind. If the column collapses under its own weight, ground-hugging currents of hot ash and gas race outward. Eventually, as the system depressurises, activity dwindles to puffs and dribbles, leaving behind a layered record of changing intensity. Recognising this sequence helps forecasters anticipate what the next hourβ€”or the next dayβ€”may bring.

E

The dangers nearest the volcano are the most obvious: searing pyroclastic surges that flatten buildings, ballistic blocks that arc from the vent, and lava flows that bury everything too slow to move. Heat and ash can ignite forests and roofs; heavy tephra loads collapse structures; toxic gases pool in low ground. These threats demand clear exclusion zones and rapid communication, because minutes matter. Yet proximity can mislead: a spectacular river of lava might draw cameras, while a less visible hazard is already gathering in the clouds above.

F

Fine ash dispersed by upper-level winds spreads the volcano’s influence far beyond the mountain. The particles are small enough to infiltrate engines and electronics, sandblast aircraft surfaces, and short-circuit power systems when wet. Even a modest eruption can close airspace, divert flights, and disrupt supply chains for days. Ash drifting over farmland clogs machinery and, when mixed with rain, forms a paste that burdens roofs. What it lacks in drama it compensates for in reach: the world notices when airports close and grids flicker.

G

When loose volcanic deposits meet heavy rain or sudden snowmelt, they can transform into fast-moving slurries that follow valleys for tens of kilometres. These flows, known as lahars, behave like liquid concrete, sweeping up boulders, bridges, and anything else in their path. Because lahars may start long after an eruption seems over, communities downslope remain at risk for months or years. Their predictability lies not in the vent but in the landscape: steep slopes, thick ash blankets, and narrow channels are the real engines of the disaster.

H

Volcanic plumes that loft sulfur gases high into the stratosphere can dim sunlight on a planetary scale. There, above weather, the gases turn into reflective aerosols that linger, cooling the surface for a year or more. The effect is temporary yet consequential: growing seasons shift, rainfall patterns adjust, and energy demand changes. While single eruptions rarely rewrite climate, their fingerprints appear in temperature records and rings of slow-grown trees. In a warming world, even small nudges to the energy balance draw interest, reminding us that volcanoes connect deep Earth to the air we breathe.

Answer Sheet (Select a heading for each paragraph)

Remember: Match by function (definition, process, cause–effect, contrast, evaluation), not by single word overlaps.

🟣 Part 3 β€” Answer Key

Sample Answer (Using the Template from Part 1)

This model shows one strong way to justify each choice using the universal sentence-by-sentence template. Compare the function of each paragraph with the scope and emphasis of the chosen heading.

One-Line Answer Pattern (Completed)

Paragraph A β†’ Heading i: cause–description β€” topic: plate motions + plumes + subduction volatiles; emphasis: systematic drivers of melting; signals: where, elsewhere, yet; reject: v (contrast styles).

Paragraph B β†’ Heading ii: cause–effect β€” topic: viscosity & dissolved gases; emphasis: gas exsolution causes explosivity; signals: in contrast; reject: xv (eruption duration).

Paragraph C β†’ Heading iv: cause–effect β€” topic: water released at subduction; emphasis: water lowers melting point, drives explosive arcs; signals: as the slab sinks… releases fluids; reject: i (general drivers).

Paragraph D β†’ Heading vi: process/sequence β€” topic: stages from ascent to fallout; emphasis: ordered chain and forecasting; signals: may form, followed by, eventually; reject: vii (local hazards list).

Paragraph E β†’ Heading vii: description/evaluation β€” topic: near-vent hazards; emphasis: need for exclusion zones; signals: the dangers nearest… minutes matter; reject: iii (misleading lava focus).

Paragraph F β†’ Heading ix: cause–effect β€” topic: fine ash and technology; emphasis: aviation, power, supply chains; signals: even a modest eruption can…; reject: x (global climate).

Paragraph G β†’ Heading viii: cause–effect β€” topic: lahars (debris + water); emphasis: landscape controls and delayed timing; signals: when… they can transform… known as lahars; reject: v (tectonic contrast).

Paragraph H β†’ Heading x: cause–effect/evaluation β€” topic: stratospheric sulfur aerosols; emphasis: temporary global cooling & societal impacts; signals: can dim sunlight… linger… cooling; reject: ix (technology only).

Template-Based Justification β€” Detailed (15–30 sentences each)
A β†’ i. Drivers of magma formation beneath the crust

Identification: For Paragraph A, I propose Heading i because the paragraph’s main function is to describe the fundamental mechanisms that generate magma below Earth’s surface. Topic Focus: The topic sentence frames plate divergence, mantle upwelling, and subduction as systematic contexts for melting. Signal Words: Transitions like β€œwhere,” β€œelsewhere,” and β€œyet” structure multiple settings while maintaining a unifying idea. Evidence Role: Named processes (ridges, rifts, plumes, subduction) operate as illustrative categories rather than isolated examples; they support the overarching drivers. Emphasis Check: The closing idea stresses common physical triggersβ€”pressure release, heat transfer, and volatile additionβ€”showing a synthesis rather than a case study. Scope Match: The heading covers all mechanisms listed without narrowing to any single setting or hazard. Function Match: Because the paragraph explains β€œwhy melting starts” in different contexts, a β€œdrivers” heading fits better than a hazard-or climate-focused one. Trap Avoidance: Mentions of subduction are supportive details, not the exclusive focus; thus iv (water at subduction) is too narrow. Synonym Awareness: β€œVolatiles” corresponds to β€œwater and other gases,” consistent with melting triggers. Comparative Fit: Heading v (contrasting eruption styles) addresses style outcomes, not generation mechanisms. Distribution Logic: A set usually opens with background causes, so β€œdrivers” is typical for the first paragraph. Paragraph Function: It defines and classifies, not evaluate or sequence events. Concluding Weight: The summary triad (pressure, heat, volatiles) is a clear signpost that the paragraph is about causes. Consistency Check: No other heading captures both breadth (multiple settings) and mechanism (melting triggers). Final Justification: Therefore, i best summarises Paragraph A by capturing the organising concept behind diverse volcanic settings.

B β†’ ii. How dissolved gases control the violence of eruptions

Identification: Paragraph B is matched with ii because it foregrounds gas exsolution as the direct cause of explosive fragmentation. Topic Focus: The paragraph contrasts silica-rich viscous magma with fluid basalt, but the emphasis is gas trapping and sudden release. Signal Words: β€œIn contrast” marks a functional comparison that highlights how gas behaves in each magma type. Evidence Role: Viscosity, crystal content, and temperature are preconditions; the decisive factor is dissolved gas, especially water. Emphasis Check: The final sentence (β€œa calm conduit can become a cannon”) centres violence arising from rapid exsolution. Scope Match: The heading’s scope (control of violence) fits the mechanism described rather than a generic contrast of styles. Function Match: This is a cause–effect mechanism paragraph, not a process timeline or hazard list. Trap Avoidance: Heading xv (long vs short eruptions) is a distractor; duration is not discussed. Synonym Awareness: β€œExsolution” aligns with β€œgas coming out of solution,” which the heading paraphrases as β€œdissolved gases.” Comparative Fit: Heading v (contrasting settings) is misplaced because the contrast here is rheological, not tectonic. Distribution Logic: After drivers (A), it makes sense to examine the immediate control on explosivity (B). Concluding Weight: The metaphor of a β€œcannon” underscores violence, matching the heading precisely. Coherence Check: Every sentence builds to the role of gas, confirming the match. Final Justification: Thus ii best captures the paragraph’s central causal claim.

C β†’ iv. Why water matters at subduction zones

Identification: Paragraph C targets the special role of water at convergent margins, so iv is appropriate. Topic Focus: It traces water from slab to mantle wedge, then to sticky, gas-rich magmas. Signal Words: β€œAs the slab sinks… releasing fluids” forms a causal chain. Evidence Role: Place references (Andes, Pacific Northwest) exemplify a general principle rather than shift the topic. Emphasis Check: The punchline is that water explains why arcs are disproportionately explosive. Scope Match: Broader headings like i would be too general; this paragraph narrows decisively to subduction-water. Function Match: Clear cause–effect, not process staging. Trap Avoidance: Heading v (contrasting settings) mentions settings but ignores water’s chemical role; the focus here is the volatile’s effect. Synonym Awareness: β€œAntifreeze for rocks” paraphrases β€œlowers melting point,” consistent with the heading’s β€œwhy it matters.” Distribution Logic: After general controls (B), we zoom into a specific tectonic situation (C). Concluding Weight: The reputation for β€œdrama” aligns with explosive outcomes driven by water. Coherence Check: Each sentence links slab water to magma properties to eruptive style. Final Justification: Therefore iv is the best summary for Paragraph C.

D β†’ vi. The sequence from magma ascent to ash fallout

Identification: Paragraph D lays out a chronological chain, so vi is ideal. Topic Focus: It starts with ascent, proceeds through degassing and column formation, and ends with fallout and waning activity. Signal Words: β€œFollowed by,” β€œmay form,” and β€œeventually” are temporal signposts. Evidence Role: The mention of column collapse and pyroclastic currents illustrates stages without derailing the sequence theme. Emphasis Check: The last sentence connects recognising the sequence to forecastingβ€”a classic process outcome. Scope Match: The heading covers the full eruption progression rather than one hazard. Function Match: Pure process description, not evaluation or contrast. Trap Avoidance: Heading vii (close-range hazards) appears inside the process, but the paragraph’s purpose is staging, not cataloguing dangers. Synonym Awareness: β€œChain of linked stages” = β€œsequence.” Distribution Logic: After mechanisms (A–C), a process map (D) is coherent. Concluding Weight: Forecasting ties the stages into practical meaning, still within process scope. Coherence Check: All sentences hang on temporal order. Final Justification: Hence vi summarises Paragraph D most accurately.

E β†’ vii. Close-range hazards and how they harm communities

Identification: Paragraph E inventories near-vent threats, so vii fits. Topic Focus: It names pyroclastic surges, ballistic blocks, lava burial, fire, roof collapse, and gases. Signal Words: β€œThe dangers nearest the volcano” clearly sets spatial scope. Evidence Role: The list demonstrates multiple mechanisms of harm, underscoring the need for exclusion zones. Emphasis Check: The sentence β€œminutes matter” emphasises immediacy and human impact. Scope Match: The heading targets close-range effects, matching the paragraph’s geographic focus. Function Match: Descriptive/evaluative, not process or global effect. Trap Avoidance: Heading iii (misleading appeal of lava) is mentioned as a warning line, but the paragraph’s centre is the full suite of near hazards, not media bias. Synonym Awareness: β€œTephra” aligns with β€œash and lapilli,” reinforcing the hazard list. Distribution Logic: After process (D), it is natural to zoom into proximal impacts (E). Concluding Weight: Exclusion zones and rapid communication show applied consequences, still within β€œclose-range hazards.” Coherence Check: Everything contributes to immediate local risk. Final Justification: Therefore vii best summarises Paragraph E.

F β†’ ix. The far-reaching effects of fine ash on technology

Identification: Paragraph F centres on dispersed fine ash impacting aviation and infrastructure, so ix is appropriate. Topic Focus: It explains particle size, transport by winds, and interactions with machinery and power systems. Signal Words: Phrases like β€œfar beyond the mountain” and β€œeven a modest eruption” highlight reach over magnitude. Evidence Role: Closed airspace, diverted flights, and clogged equipment are examples of technological disruption. Emphasis Check: The payoff lineβ€”β€œthe world notices when airports close and grids flicker”—cements the theme. Scope Match: Technology-focused impacts align with the heading; climate is not the focus here. Function Match: Cause–effect, not process or evaluation of benefits. Trap Avoidance: Heading x (global climate) is a different scale and mechanism (sulfur aerosols), not present in F. Synonym Awareness: β€œSandblast,” β€œshort-circuit,” and β€œpaste” paraphrase damage modes without changing the central idea. Distribution Logic: Having covered local hazards (E), this paragraph extends to remote, technological impacts (F). Concluding Weight: The societal signal (airports, grids) guides the correct heading choice. Coherence Check: Each sentence ties back to fine ash and systems. Final Justification: Thus ix captures Paragraph F precisely.

G β†’ viii. When volcanic debris mixes with water

Identification: Paragraph G describes laharsβ€”volcanic debris plus waterβ€”so viii is exact. Topic Focus: The transformation into fast-moving slurries and their valley-following behaviour is central. Signal Words: β€œWhen… they can transform” indicates conditional cause; β€œknown as lahars” defines the process. Evidence Role: Bridges, boulders, and delayed timing illustrate destructive potential beyond the eruption window. Emphasis Check: The key insight is that landscape, not the vent, governs risk post-eruption. Scope Match: The heading mentions β€œmixes with water,” mirroring the paragraph’s mechanism. Function Match: Cause–effect with definitional elements. Trap Avoidance: Heading v (contrast of settings) is irrelevant; tectonics do not explain lahars here. Synonym Awareness: β€œLiquid concrete” paraphrases viscosity/solid load without shifting focus. Distribution Logic: After ash-technology (F), another indirect hazard with delayed timing (G) fits the set’s variety. Concluding Weight: The months-to-years emphasis justifies preparedness independent of eruption status. Coherence Check: All sentences link debris-water mixing to downstream risk. Final Justification: Hence viii summarises Paragraph G accurately.

H β†’ x. Volcanoes and temporary shifts in global climate

Identification: Paragraph H explains how stratospheric sulfur aerosols cool climate temporarily; thus x applies. Topic Focus: The altitude (stratosphere), conversion to reflective aerosols, and persistence drive the climate signal. Signal Words: β€œCan dim sunlight,” β€œlinger,” and β€œtemporary yet consequential” describe effect, duration, and significance. Evidence Role: Temperature records and tree rings serve as corroborating examples for the global effect. Emphasis Check: The stress on β€œtemporary yet consequential” matches β€œtemporary shifts” in the heading. Scope Match: Global and climatic, not technological or local. Function Match: Cause–effect with evaluative nuance about societal relevance. Trap Avoidance: Heading ix would misplace the focus onto technology; here the impact is planetary energy balance. Synonym Awareness: β€œNudges to the energy balance” = radiative forcing changes, coherent with β€œshifts.” Distribution Logic: As a concluding paragraph, a broad climate lens fits well. Concluding Weight: The final line connects deep Earth to atmosphere, a classic summative move. Coherence Check: Every sentence supports the climatic angle. Final Justification: Therefore x best encapsulates Paragraph H.

Compact Template (Copy-Ready Justifications)

A β†’ i: Function = description of core drivers; topic = plate divergence, plumes, subduction volatiles; emphasis = pressure/heat/volatiles; signals = where/elsewhere/yet; reject = v.

B β†’ ii: Function = cause–effect; topic = viscosity + dissolved gas; emphasis = gas exsolution controls violence; signals = in contrast; reject = xv.

C β†’ iv: Function = cause–effect; topic = slab water lowers melting point; emphasis = explosive arcs; signals = releases fluids; reject = i.

D → vi: Function = process/sequence; topic = ascent→column→fallout; emphasis = staging aids forecasting; signals = followed by/eventually; reject = vii.

E β†’ vii: Function = descriptive/evaluative; topic = near-vent hazards; emphasis = exclusion zones & minutes matter; signals = nearest; reject = iii.

F β†’ ix: Function = cause–effect; topic = fine ash & technology; emphasis = aviation/power disruptions; signals = far beyond; reject = x.

G β†’ viii: Function = cause–effect/definition; topic = lahars (debris + water); emphasis = landscape-controlled risk; signals = transform/known as; reject = v.

H β†’ x: Function = cause–effect/evaluation; topic = stratospheric aerosols; emphasis = temporary global cooling; signals = linger/temporary; reject = ix.

🟒 Part 4 β€” Vocabulary

How to Study These Words

Each item includes BrE & AmE IPA, part(s) of speech, common patterns, a clear definition, an example with a quick gloss, useful synonyms, and typical learner mistakes. Use the β€œCopy All” button to save them to your notes.

Key Words
1) magma β€” /ˈmΓ¦Ι‘mΙ™/ (BrE) β€’ /ˈmΓ¦Ι‘mΙ™/ (AmE) β€” noun

Patterns: magma + chamber; magma + rises; molten magma

Definition: Hot, molten rock stored beneath Earth’s surface that can feed volcanic eruptions.

Example: β€œSensors showed the magma rising, hinting at an eruption.” (= molten rock moved upward)

Synonyms: molten rock (approx.)

Common mistakes: ❌ β€œmagmas” for general reference (use uncountable); ❌ confusing magma (below ground) with lava (on the surface).

2) viscosity β€” /vΙͺsˈkΙ’sΙͺti/ (BrE) β€’ /vΙͺsˈkɑːsΙͺti/ (AmE) β€” noun

Patterns: high/low viscosity; viscosity + controls/affects

Definition: The thickness or internal resistance to flow of a liquid or semi-liquid.

Example: β€œHigh viscosity magma traps gases and raises explosivity.” (= thick magma keeps gas inside)

Synonyms: thickness, stickiness (approx.)

Common mistakes: ❌ β€œviscousity”; ❌ using it as an adjective (use β€œviscous”).

3) exsolution β€” /ΛŒΙ›kssΙ™Λˆluːʃ(Ι™)n/ (BrE) β€’ /ˌeksoʊˈluːʃən/ (AmE) β€” noun

Patterns: gas exsolution; rapid/sudden exsolution

Definition: The process by which dissolved gases come out of a liquid (magma) as bubbles.

Example: β€œRapid gas exsolution can turn a gentle vent into a cannon.” (= sudden bubble growth drives blasts)

Synonyms: degassing (related, not identical)

Common mistakes: ❌ spelling β€œexplosion” by accident; ❌ treating it as a verb (β€œexsolutioned”).

4) pyroclastic flow β€” /ˌpaΙͺrΙ™ΚŠΛˆklΓ¦stΙͺk ˌflΙ™ΚŠ/ (BrE) β€’ /ˌpaΙͺroʊˈklΓ¦stΙͺk floʊ/ (AmE) β€” noun (countable)

Patterns: deadly pyroclastic flows; a pyroclastic-flow hazard

Definition: A fast, ground-hugging current of hot gas and ash from a collapsing eruption column.

Example: β€œA pyroclastic flow swept down the valley in minutes.” (= hot ash cloud raced along the ground)

Synonyms: ash surge (approx.)

Common mistakes: ❌ β€œpyroclastic fall” (different process); ❌ using it for simple smoke or steam.

5) tephra β€” /ˈtΙ›frΙ™/ (BrE) β€’ /ˈtΙ›frΙ™/ (AmE) β€” noun (uncountable/collective)

Patterns: tephra fall; fine/coarse tephra

Definition: Fragmented volcanic material (ash, lapilli, blocks) ejected during an eruption.

Example: β€œRoofs failed under wet tephra after the storm.” (= ash/rocks collected on roofs)

Synonyms: ejecta (technical)

Common mistakes: ❌ using β€œtephras” for plural in general; ❌ confusing with only fine ash.

6) lahar β€” /lΙ™Λˆhɑː/ (BrE) β€’ /lΙ™Λˆhɑːr/ (AmE) β€” noun (countable)

Patterns: trigger a lahar; lahar pathway/channel

Definition: A fast-moving volcanic mudflow formed when ash and debris mix with water.

Example: β€œRain on fresh ash triggered a destructive lahar.” (= water + debris made a concrete-like flow)

Synonyms: volcanic mudflow

Common mistakes: ❌ calling any flood a lahar; ❌ ignoring delayed lahars long after eruptions.

7) subduction β€” /sΙ™bˈdʌkΚƒn/ (BrE) β€’ /sΙ™bˈdʌkΚƒΙ™n/ (AmE) β€” noun

Patterns: subduction zone; oceanic-plate subduction

Definition: The process where one tectonic plate sinks beneath another into the mantle.

Example: β€œSubduction introduces water that promotes melting and explosivity.” (= sinking plate adds water to mantle)

Synonyms: plate descent (descriptive)

Common mistakes: ❌ β€œseduction” (spelling!); ❌ assuming all subduction volcanoes are gentle.

8) mantle plume β€” /ˈmΓ¦nt(Ι™)l ˈpluːm/ (BrE) β€’ /ˈmΓ¦ntl ˈplum/ (AmE) β€” noun (countable)

Patterns: hotspot/mantle plume; plume-fed volcanism

Definition: A rising column of hot mantle rock thought to cause hotspot volcano chains.

Example: β€œThe island chain aligns with a mantle plume track.” (= volcanoes formed as the plate moved over a hotspot)

Synonyms: hotspot source

Common mistakes: ❌ treating β€œplume” as smoke; ❌ assuming plumes occur only in oceans.

9) degassing β€” /ˌdiːˈɑæsΙͺΕ‹/ (BrE) β€’ /ˌdiːˈɑæsΙͺΕ‹/ (AmE) β€” noun/gerund

Patterns: continuous/rapid degassing; volcano + is degassing

Definition: The release of gases from magma or volcanic vents.

Example: β€œStrong degassing suggested pressure changes at depth.” (= gas release hinted at shifting conditions)

Synonyms: venting, outgassing

Common mistakes: ❌ writing β€œde-gassing” inconsistently; ❌ using it only for factories (it’s also geologic).

10) eruption column β€” /ΙͺˈrʌpΚƒn ˈkΙ’lΙ™m/ (BrE) β€’ /ΙͺˈrʌpΚƒΙ™n ˈkɑːlΙ™m/ (AmE) β€” noun (countable)

Patterns: towering eruption column; column collapse

Definition: A vertical cloud of ash and gas rising above a vent during an explosive eruption.

Example: β€œThe eruption column reached the stratosphere within minutes.” (= the ash cloud rose very high)

Synonyms: eruption plume (related)

Common mistakes: ❌ confusing with lava fountain; ❌ thinking collapse is harmless (it can form flows).

11) stratosphere β€” /ˈstrΓ¦tΙ™sfΙͺΙ™/ (BrE) β€’ /ˈstrΓ¦tΙ™sfΙͺr/ (AmE) β€” noun

Patterns: reach the stratosphere; stratospheric aerosols

Definition: A stable atmospheric layer above the troposphere where volcanic gases can persist.

Example: β€œSulfur entered the stratosphere, reducing sunlight at the surface.” (= gases rose above weather systems)

Synonyms: upper atmosphere (approx.)

Common mistakes: ❌ mixing with β€œionosphere”; ❌ assuming all plumes reach this height.

12) aerosol β€” /ˈeΙ™rΙ™sΙ’l/ (BrE) β€’ /ˈerΙ™sɔːl/ (AmE) β€” noun

Patterns: sulfate aerosols; aerosol layer/formation

Definition: Tiny liquid or solid particles suspended in a gas; volcanic sulfur aerosols reflect sunlight.

Example: β€œA veil of sulfate aerosol cooled temperatures for a year.” (= small particles reflected sunlight)

Synonyms: particulate haze (approx.)

Common mistakes: ❌ using only for spray cans; ❌ writing β€œaerosoil.”

13) basaltic β€” /bΙ™ΛˆsɔːltΙͺk/ (BrE) β€’ /bΙ™ΛˆsɔːltΙͺk/ (AmE) β€” adjective

Patterns: basaltic lava/flows; basaltic magma

Definition: Made of or relating to basalt; typically low-silica, fluid, and less explosive.

Example: β€œThe basaltic flow advanced quickly but cooled to a dark crust.” (= runny low-silica lava moved fast)

Synonyms: mafic (technical)

Common mistakes: ❌ assuming basaltic eruptions are never dangerous; ❌ spelling β€œbasaltical.”

14) andesitic β€” /ˌændΙ™ΛˆziːtΙͺk/ (BrE) β€’ /ˌændΙͺˈziːtΙͺk/ (AmE) β€” adjective

Patterns: andesitic magma/arc; andesitic stratovolcano

Definition: Relating to andesite; intermediate-silica magma common at subduction zones.

Example: β€œThe volcano produced andesitic domes before explosive activity.” (= medium-silica magma built domes)

Synonyms: intermediate (composition)

Common mistakes: ❌ pronouncing /ˈændΙ™saΙͺt/ for the adjective; use /ˈændΙͺzaΙͺt/ for the rock (AmE).

15) silica β€” /ˈsΙͺlΙͺkΙ™/ (BrE) β€’ /ˈsΙͺlΙͺkΙ™/ (AmE) β€” noun (uncountable)

Patterns: high/low silica content; silica-rich/poor

Definition: A chemical component (SiOβ‚‚) that increases magma viscosity as its proportion rises.

Example: β€œHigher silica made the melt thicker and more explosive.” (= more SiOβ‚‚ raised viscosity)

Synonyms: silicon dioxide (chemical term)

Common mistakes: ❌ β€œsilicone” (that’s a polymer); ❌ treating silica as countable.

16) conduit β€” /ˈkΙ’ndjuːΙͺt/ (BrE) β€’ /ˈkɑːndwΙͺt/ (AmE) β€” noun (countable)

Patterns: volcanic conduit; blocked/narrow conduit

Definition: The main passage through which magma and gas move toward the surface.

Example: β€œA clogged conduit increased pressure beneath the crater.” (= blocked pipe raised pressure)

Synonyms: channel, vent (related)

Common mistakes: ❌ saying β€œcanduit”; ❌ confusing with β€œduct” in buildings (different context).

17) ballistic (projectiles) β€” /bΙ™ΛˆlΙͺstΙͺk/ (BrE) β€’ /bΙ™ΛˆlΙͺstΙͺk/ (AmE) β€” adjective

Patterns: ballistic blocks; ballistic trajectory

Definition: Rocks ejected from a volcano that travel along curved paths due to gravity.

Example: β€œBallistic blocks smashed roofs near the crater.” (= thrown rocks landed on buildings)

Synonyms: thrown, ejected (contextual)

Common mistakes: ❌ using only for missiles; ❌ ignoring danger beyond ash zones.

18) ashfall β€” /ΛˆΓ¦Κƒfɔːl/ (BrE) β€’ /ΛˆΓ¦Κƒfɔːl/ (AmE) β€” noun (uncountable/countable event)

Patterns: heavy/wet ashfall; ashfall advisory

Definition: The settling of volcanic ash from the air onto the ground.

Example: β€œWet ashfall overloaded power lines and trees.” (= sticky ash caused failures)

Synonyms: tephra fall (technical)

Common mistakes: ❌ writing β€œash fall” inconsistently in technical texts; both forms occur, choose one style.

19) forecast β€” /ˈfɔːkɑːst/ (BrE) β€’ /ˈfɔːrkΓ¦st/ (AmE) β€” noun/verb

Patterns: to forecast X; eruption forecast; probabilistic forecast

Definition: (n./v.) A prediction, often with probabilities, of future activity based on data.

Example: β€œScientists forecast a high chance of ash within 24 hours.” (= predicted with evidence)

Synonyms: predict, projection (n.)

Common mistakes: ❌ overusing certain; good forecasts include uncertainty ranges.

20) exclusion zone β€” /Ιͺkˈskluːʒən zΙ™ΚŠn/ (BrE) β€’ /Ιͺkˈskluːʒən zoʊn/ (AmE) β€” noun (countable)

Patterns: set/enforce an exclusion zone; within/outside the zone

Definition: A restricted area around a hazard where entry is forbidden for safety.

Example: β€œThe mayor expanded the exclusion zone after new cracks appeared.” (= larger no-entry area for protection)

Synonyms: restricted area, no-go zone

Common mistakes: ❌ entering to film or take photos; ❌ assuming zones are permanent (they can change fast).

🟠 Part 5 β€” Phrases & Expressions

How to Learn These Phrases

Each expression includes BrE & AmE IPA, part(s) of speech, common patterns, a clear definition, a context-rich example with a brief gloss, synonyms, and frequent learner mistakes. These are high-value collocations drawn from the passage topic and IELTS-style texts.

Phrases & Expressions
1) lower the melting point β€” /ˈlΙ™ΚŠΙ™ Γ°Ι™ ˈmeltΙͺΕ‹ pΙ”Ιͺnt/ (BrE) β€’ /ˈloΚŠΙ™r Γ°Ι™ ˈmeltΙͺΕ‹ pΙ”Ιͺnt/ (AmE) β€” verb phrase

Patterns: X lowers the melting point of Y; lower the melting point by amount

Definition: To reduce the temperature at which a material begins to melt.

Example: β€œWater released at subduction lowers the melting point of the mantle wedge.” (= makes rock melt at a lower temperature)

Synonyms: depress the melting point

Mistakes: ❌ β€œdown the melting point”; ❌ using β€œdecrease of the melting point” (use β€œdecrease the melting point”).

2) come out of solution β€” /kʌm aʊt Ι™v sΙ™Λˆluːʃn/ (BrE) β€’ /kʌm aʊt Ι™v sΙ™Λˆluːʃən/ (AmE) β€” phrasal/verb phrase

Patterns: gases come out of solution; X comes out of solution rapidly

Definition: (Of a dissolved substance) to separate from a liquid as bubbles or particles.

Example: β€œIf pressure drops quickly, dissolved water comes out of solution as bubbles.” (= forms bubbles suddenly)

Synonyms: exsolve; separate

Mistakes: ❌ β€œcome from solution”; ❌ β€œexit the solution” (unnatural).

3) trap gases β€” /trΓ¦p ˈɑæsΙͺz/ (BrE) β€’ /trΓ¦p ˈɑæsΙͺz/ (AmE) β€” verb phrase

Patterns: viscous magma traps gases; trap X inside Y

Definition: To hold gases so they cannot escape.

Example: β€œSilica-rich magma traps gases, increasing the chance of explosive release.” (= holds gas in)

Synonyms: confine gases; retain gases

Mistakes: ❌ β€œcatch gases” (too informal); ❌ β€œlock the gas” (unnatural article use).

4) build pressure β€” /bΙͺld ˈprΙ›ΚƒΙ™/ (BrE) β€’ /bΙͺld ˈprΙ›ΚƒΙ™r/ (AmE) β€” verb phrase

Patterns: build pressure beneath/inside; pressure builds

Definition: To increase the force exerted by gas or fluid in a confined space.

Example: β€œBlocked conduits allow gas to build pressure until failure.” (= pressure rises over time)

Synonyms: accumulate pressure; ramp up pressure

Mistakes: ❌ β€œmake pressure” (use β€œbuild/raise pressure”).

5) erupt explosively β€” /Ιͺˈrʌpt ΙͺkˈsplΙ™ΚŠsΙͺvli/ (BrE) β€’ /Ιͺˈrʌpt ΙͺkˈsploʊsΙͺvli/ (AmE) β€” verb + adverb

Patterns: volcano + erupts explosively/effusively

Definition: To burst out with great force, throwing ash and gas violently.

Example: β€œGas-rich andesitic magma may erupt explosively.” (= blow out violently)

Synonyms: blow violently; detonate (contextual)

Mistakes: ❌ β€œexplode erupt” (double verb); ❌ β€œerupt explosion” (noun misuse).

6) ash fallout β€” /Γ¦Κƒ ˈfɔːlaʊt/ (BrE) β€’ /Γ¦Κƒ ˈfɔːlaʊt/ (AmE) β€” noun phrase

Patterns: widespread/local ash fallout; heavy/wet fallout

Definition: The settling of ash particles from an eruption plume.

Example: β€œWinds carried ash fallout across farms downwind.” (= ash settled over fields)

Synonyms: ashfall; tephra fall

Mistakes: ❌ β€œash fall down” (redundant phrasal verb).

7) column collapse β€” /ˈkΙ’lΙ™m kΙ™ΛˆlΓ¦ps/ (BrE) β€’ /ˈkɑːlΙ™m kΙ™ΛˆlΓ¦ps/ (AmE) β€” noun phrase

Patterns: lead to column collapse; risk of column collapse

Definition: When an eruption column falls back to the ground, often generating pyroclastic flows.

Example: β€œStrong winds and high load triggered column collapse.” (= the plume fell and formed ground currents)

Synonyms: plume collapse

Mistakes: ❌ β€œcolumn fall” (too general); ❌ thinking it is harmless.

8) ground-hugging currents β€” /ˈɑraʊnd ˌhʌɑΙͺΕ‹ ˈkʌrΙ™nts/ (BrE) β€’ /ˈɑraʊnd ˌhʌɑΙͺΕ‹ ˈkɜːrΙ™nts/ (AmE) β€” noun phrase (plural)

Patterns: hot ground-hugging currents; currents race/flow

Definition: Fast, dense clouds of ash and gas that move along the surface.

Example: β€œGround-hugging currents raced down the flanks after the collapse.” (= pyroclastic flows)

Synonyms: pyroclastic flows; ash surges

Mistakes: ❌ calling them β€œlava clouds” (different phenomenon).

9) downwind of the volcano β€” /ˌdaʊnˈwΙͺnd Ι™v Γ°Ι™ vΙ’lˈkeΙͺnΙ™ΚŠ/ (BrE) β€’ /ˌdaʊnˈwΙͺnd Ι™v Γ°Ι™ vɑːlˈkeΙͺnoʊ/ (AmE) β€” prepositional phrase

Patterns: areas downwind of X; travel downwind

Definition: In the direction the wind is blowing toward from the source.

Example: β€œSchools downwind of the volcano closed due to ash.” (= in the wind’s path)

Synonyms: leeward of (formal)

Mistakes: ❌ β€œunderwind”; ❌ confusing with β€œupwind.”

10) close-range hazards β€” /ˌklΙ™ΚŠs ˈreΙͺndΚ’ ˈhΓ¦zΙ™dz/ (BrE) β€’ /ˌkloʊs ˈreΙͺndΚ’ ˈhΓ¦zΙ™rdz/ (AmE) β€” noun phrase (plural)

Patterns: manage/mitigate close-range hazards; immediate/near-vent hazards

Definition: Dangers that occur near the source, such as pyroclastic flows and ballistic blocks.

Example: β€œEvacuation aims to avoid close-range hazards when minutes matter.” (= dangers right next to the vent)

Synonyms: proximal hazards; near-vent risks

Mistakes: ❌ using for distant ash effects.

11) far-reaching effects β€” /ˌfɑː ˈriːtΚƒΙͺΕ‹ ΙͺˈfΙ›kts/ (BrE) β€’ /ˌfɑːr ˈriːtΚƒΙͺΕ‹ ΙͺˈfΙ›kts/ (AmE) β€” noun phrase (plural)

Patterns: have far-reaching effects on X

Definition: Impacts that spread widely and influence many systems.

Example: β€œFine ash has far-reaching effects on aviation and power.” (= wide, serious influence)

Synonyms: wide-ranging consequences

Mistakes: ❌ β€œfar-reached effects” (wrong form).

12) mix with water β€” /mΙͺks wΙͺΓ° ˈwɔːtΙ™/ (BrE) β€’ /mΙͺks wΙͺΓ° ˈwɔːtΙ™r/ (AmE) β€” verb phrase

Patterns: debris/ash mixes with water; mix with melt/rain

Definition: To combine with water, producing a new substance or flow.

Example: β€œDeposits can mix with water and form lahars long after eruption.” (= combine to create mudflows)

Synonyms: combine with water; blend with water

Mistakes: ❌ β€œmix to water”; use β€œmix with.”

13) follow a valley/channel β€” /ˈfΙ’lΙ™ΚŠ Ι™ ˈvΓ¦li/ (BrE) β€’ /ˈfɑːloʊ Ι™ ˈvΓ¦li/ (AmE) β€” verb phrase

Patterns: lahars follow valleys; flows follow channels for distance

Definition: (Of a flow) to move along the path shaped by the landscape.

Example: β€œLahars often follow valleys for tens of kilometres.” (= move within river paths)

Synonyms: travel along valleys; run down channels

Mistakes: ❌ β€œfollowed to the valley” (preposition error).

14) close/ shut airspace β€” /klΙ™ΚŠz ˈeΙ™ΛŒspeΙͺs/ (BrE) β€’ /kloʊz ˈerˌspeΙͺs/ (AmE) β€” verb phrase

Patterns: authorities close airspace; airspace closure over region

Definition: To stop flights from using a region of sky for safety reasons.

Example: β€œRegulators closed airspace as ash reached cruising altitudes.” (= flights were stopped)

Synonyms: suspend flights; ground aircraft (context)

Mistakes: ❌ β€œclose the airs” (incorrect noun); ❌ β€œclose airport” (different object).

15) short-circuit a system β€” /ʃɔːt ˈsɜːkΙͺt Ι™ ˈsΙͺstΙ™m/ (BrE) β€’ /ʃɔːrt ˈsɜːrkΙͺt Ι™ ˈsΙͺstΙ™m/ (AmE) β€” verb phrase

Patterns: ash/wet ash short-circuits equipment

Definition: To cause an electrical fault by creating an unintended path.

Example: β€œWet ash can short-circuit power lines and transformers.” (= cause faults and outages)

Synonyms: cause an electrical fault; trip a system

Mistakes: ❌ β€œshortcut” (different meaning).

16) dim sunlight β€” /dΙͺm ˈsʌnlaΙͺt/ (BrE) β€’ /dΙͺm ˈsʌnlaΙͺt/ (AmE) β€” verb phrase

Patterns: aerosols dim sunlight; dim sunlight at the surface

Definition: To reduce the intensity of incoming solar radiation.

Example: β€œStratospheric aerosols can dim sunlight for a year or more.” (= make sunshine weaker)

Synonyms: reduce insolation; cut sunlight

Mistakes: ❌ β€œmake the sun dark” (unnatural phrasing).

17) temporary cooling β€” /ˈtΙ›mp(Ι™)rΙ™ri ˈkuːlΙͺΕ‹/ (BrE) β€’ /ˈtΙ›mpΙ™ΛŒrΙ›ri ˈkuːlΙͺΕ‹/ (AmE) β€” noun phrase

Patterns: cause/lead to temporary cooling; a period of temporary cooling

Definition: A short-term drop in average temperature.

Example: β€œLarge eruptions can produce temporary cooling worldwide.” (= short global temperature fall)

Synonyms: short-term cooling; transient cooling

Mistakes: ❌ β€œtemporarily cool noun” (use noun phrase).

18) weigh costs and benefits β€” /weΙͺ kΙ’sts Ι™nd ˈbΙ›nΙͺfΙͺts/ (BrE) β€’ /weΙͺ kɔːsts Ι™nd ˈbΙ›nΙ™fΙͺts/ (AmE) β€” verb phrase (set)

Patterns: weigh costs and benefits of action

Definition: To evaluate positive and negative outcomes before deciding.

Example: β€œOfficials must weigh costs and benefits before closing airspace.” (= judge pros and cons)

Synonyms: assess trade-offs; balance pros and cons

Mistakes: ❌ β€œweight” as a verb (use β€œweigh”).

19) set / enforce an exclusion zone β€” /set/ β€’ /Ιͺnˈfɔːs Ι™n Ιͺkˈskluːʒən zΙ™ΚŠn/ (BrE) β€’ /Ιͺnˈfɔːrs Ι™n Ιͺkˈskluːʒən zoʊn/ (AmE) β€” verb phrase

Patterns: set/enforce/expand an exclusion zone around area

Definition: To create or apply a no-entry area near a hazard.

Example: β€œAuthorities enforced an exclusion zone after new cracks opened.” (= blocked the area for safety)

Synonyms: impose a restricted area

Mistakes: ❌ β€œexclusion area zone” (redundant).

20) from detection to decision β€” /frΙ’m dΙͺˈtΙ›kΚƒn tΙ™ dΙͺˈsΙͺΚ’n/ (BrE) β€’ /frʌm dΙͺˈtΙ›kΚƒΙ™n tΙ™ dΙͺˈsΙͺΚ’Ι™n/ (AmE) β€” prepositional phrase (set)

Patterns: move from detection to decision; pipeline from detection to decision

Definition: The path from observing a signal to taking action or issuing guidance.

Example: β€œModern monitoring speeds the path from detection to decision.” (= faster observation-to-action)

Synonyms: observation-to-action pipeline

Mistakes: ❌ β€œfrom detection into decision” (use β€œto”).

πŸ”Ί Part 6 β€” Vocabulary & Expressions Quiz

How this Quiz Works

You will get 10 questions selected at random from a 50-question pool. Choose an answer to immediately see a detailed explanation (10–15 sentences), built from the strategy in Part 1 and facts from the passage in Part 2. You can reshuffle a new set any time.

Score: 0 / 10 β€’ Answered: 0 / 10

Tip: Match by function and scope, watch for signals (β€œwhereas, therefore, eventually”), and ignore the word-match trap.

Quiz (MCQ)