Volcanoes: earth-shattering news: reading answers and analysis
Volcanoes have shaped the earth, building continents and probably supplying the atmosphere and the water in the oceans. The passage explains how mantle flow cracks the crust into plates, describes slow, faster and explosive eruptions, and ends with why volcanoes are so hard to predict.
The headings (14-17) take the sections in order. The short answers (18-21) run from B to D. The summary (22-26) goes back to A for its first gap and then stays in the first three paragraphs of C.
Answer key and self-check
Type what you wrote and hit mark. Hide the key first if you haven't done the passage yet. Every question number jumps to its explanation.
How to attack this block: Each heading matches the overall structure of a section, not its opening line. A opens with a dramatic eruption but is about how volcanoes shaped the planet. C opens with causes but is mostly about types of eruption. Two headings are unused, and one of them shares a key word with D.
Question 14
Answer: iiiSection A, second paragraph
Which heading fits Section A?
Vulcanism, the name given to volcanic processes, really has shaped the world. Eruptions have rifted continents, raised mountain chains, constructed islands and shaped the topography of the earth.
Question says → Passage says
Volcanoes and the features of our planetshaped the topography of the earth / made the continents / provided all the water for the oceans
Why: Section A is a list of what volcanoes have built: continents, mountains, islands, the ocean floor, the atmosphere and the oceans' water. That's volcanoes and the features of our planet, heading iii.
The trap: The opening describes a violent eruption, which pulls people towards iv (types of eruption). That's just the hook. The writer says the classic eruption is 'only a tiny part' of the story.
Question 15
Answer: iSection B, second paragraph
Which heading fits Section B?
The flow, thought to be in the form of convection currents, is powerful enough to fracture the 'eggshell' of the crust into plates… These fracture zones, where the collisions occur, are where earthquakes happen. And, very often, volcanoes.
Question says → Passage says
Causes of volcanic eruptionpowerful enough to fracture the 'eggshell' of the crust / These fracture zones… are where… volcanoes
Why: B explains the earth's structure (the egg comparison) and how mantle flow cracks the crust into plates, which is where volcanoes happen. It's about why eruptions occur, so heading i.
The trap: C also deals with mechanisms (rocks heating and rising), so i can seem to fit there too. But C is organised around the different ways magma comes out, which is iv.
Question 16
Answer: ivSection C, second and third paragraphs
Which heading fits Section C?
Sometimes it is slow… Sometimes - as in Northern Ireland, Wales and the Karoo in South Africa - the magma rose faster… Sometimes the magma moves very swiftly indeed.
Question says → Passage says
Different types of volcanic eruptionEvery eruption is different / Sometimes it is slow / Sometimes the magma moves very swiftly indeed
Why: The three 'Sometimes' openings give you the structure: slow, faster, very swift. Each produces a different kind of eruption, and the pumice and basalt evidence tells them apart. Heading iv.
The trap: Heading i (causes) is tempting because C starts with weaknesses and hot spots. That's only the first paragraph. Most of the section sorts eruptions into types.
Question 17
Answer: viSection D, first sentence
Which heading fits Section D?
But volcanoes are not very predictable. That is because geological time is not like human time.
Question says → Passage says
The unpredictability of volcanic eruptionsvolcanoes are not very predictable / with only a small warning, the mountain blows its top
Why: D opens by saying volcanoes aren't predictable and explains why: they plug themselves for centuries, then blow with little warning. Heading vi.
The trap: Heading ii (efforts to predict eruptions) uses the same word, but nobody in D is trying to predict anything. The section is about why prediction is hard.
Short answers (NO MORE THAN THREE WORDS AND/OR A NUMBER)
Questions 18-21
How to attack this block: Three questions ask 'what is it called', so look for naming signals: 'what are called', a definition between dashes, words in quotation marks. Don't trust general knowledge here, because 'lava' is the obvious answer where the passage uses 'magma'.
Question 18
Answer: platesSection B, second paragraph, and Section C, last paragraph
Also accepted: tectonic plates
What are the sections of the crust linked to volcanic activity called?
you can see the rough outlines of what are called tectonic plates - the plates which make up the earth's crust and mantle
Question says → Passage says
sections of the earth's crustthe plates which make up the earth's crust and mantle
often associated with volcanic activityLook at maps of volcanoes, earthquakes and island chains
Why: 'What are called' signals a name. The crust is broken into 'plates', and the passage gives the full name 'tectonic plates'. Either is accepted.
The trap: 'Fracture zones' are where plates meet, not the sections themselves. 'Mantle' is the layer under the crust.
Question 19
Answer: magmaSection C, second paragraph
What is the name for molten rock from the mantle?
vast bubbles of magma - molten rock from the mantle - inch towards the surface
Question says → Passage says
molten rock from the mantlemolten rock from the mantle
Why: The definition sits between dashes right after the word it defines. That word is 'magma'.
The trap: 'Lava' is the obvious guess from general knowledge, and it's in the passage too, but the passage defines 'magma' with these exact words.
Question 20
Answer: ring of fireSection C, last paragraph
Also accepted: the ring of fire / the Pacific ring of fire
What is the earthquake zone around the Pacific called?
The most dramatic of these is the Pacific 'ring of fire' where there have been the most violent explosions
Question says → Passage says
on the Pacific Oceanthe Pacific
called'ring of fire'
Why: The quotation marks show it's a name. 'Ring of fire' is three words, which keeps you safely inside the limit. Don't add 'Pacific', since the question already gives it.
The trap: Don't write a volcano name like 'Mount Pinatubo'. The question asks for the zone, not one place in it.
Question 21
Answer: 600Section D, first paragraph, last sentence
Also accepted: 600 years
How long did Mount Pinatubo stay quiet?
a huge, hard, stable plug which blocks any further eruption until the pressure below becomes irresistible. In the case of Mount Pinatubo, this took 600 years.
Question says → Passage says
remain inactiveblocks any further eruption
Why: The plug blocks eruptions until the pressure wins, and for Pinatubo that took 600 years. The question asks 'how many years', so '600' is enough.
The trap: 1991 (the eruption date in the subtitle) and 1815 (Tambora) are other numbers nearby. Neither is a length of time.
Summary completion (NO MORE THAN TWO WORDS)
Questions 22-26
How to attack this block: The summary runs through the three speeds of eruption in C. Check grammar closely: one gap needs a verb ending in -s and another a plural noun. Give a country where the summary lists countries, not the name of a plateau.
Question 22
Answer: waterSection A, third paragraph
Besides the atmosphere, what may volcanoes have produced?
they are also thought to have made the world's first stable atmosphere and provided all the water for the oceans, rivers and ice-caps
Question says → Passage says
may also have producedare also thought to have made… and provided
the world's atmosphere andthe world's first stable atmosphere and
Why: 'Thought to have' matches 'may', and after 'atmosphere and' comes the water for the oceans, rivers and ice-caps. One word, 'water', covers all three.
The trap: 'Oceans' fits the grammar but only names one of the places the water went. 'Soil' comes at the end of A, but it isn't paired with the atmosphere there.
Question 23
Answer: magmaSection C, second paragraph, first sentence
What sometimes moves slowly and forms granite outcrops?
Sometimes it is slow: vast bubbles of magma - molten rock from the mantle - inch towards the surface, cooling slowly, to show through as granite extrusions
Question says → Passage says
moves slowlyinch towards the surface
outcrops of granitegranite extrusions
Why: 'Inch towards' means move very slowly, and the subject is magma. 'Granite extrusions' are the outcrops. Answer: 'magma'.
The trap: 'Lava' again tempts people, but in this sentence the slow-moving material is the magma.
Question 24
Answer: IndiaSection C, second paragraph, last sentence
Also accepted: western India
Where else, besides Northern Ireland, Wales and South Africa, does magma flow out in thick sheets?
In the Deccan plateau in western India, there are more than two million cubic kilometres of lava, some of it 2,400 metres thick
Question says → Passage says
thick horizontal sheetsflowed out horizontally on to the surface in vast thick sheets
Why: The summary lists countries, so the gap needs the country of the Deccan plateau, which is India. 'Western India' is also accepted.
The trap: 'Deccan plateau' is the place in the passage, but it isn't a country like the others in the list. 'Karoo' is in South Africa, which is already given.
Question 25
Answer: explodesSection C, third paragraph
What does the lava do when it comes out very fast?
the lava glows with heat, it begins to froth, and it explodes with tremendous force
Question says → Passage says
violentlywith tremendous force
emerges very quicklythe magma moves very swiftly indeed
Why: The gap comes before 'violently', so it needs a verb that agrees with 'lava': 'explodes'. 'With tremendous force' becomes 'violently'.
The trap: 'Froths' and 'glows' are also verbs in that sentence, but neither goes with 'violently'. Keep the -s ending to match 'emerges'.
Question 26
Answer: gasesSection C, third paragraph
Also accepted: trapped gases
What is released because the magma moves so suddenly?
It does not have time to cool as it surges upwards. The gases trapped inside the boiling rock expand suddenly
Question says → Passage says
the magma moves so suddenlythe magma moves very swiftly indeed… It does not have time to cool
Why: The passage explains the explosion by the trapped gases expanding suddenly. The gap takes a plural noun ('are emitted'), so 'gases'.
The trap: 'Lava' follows in the next sentence, flowing over the lip of the crater, but it flows rather than being emitted, and it's singular.
'Lava' is the everyday word, but the passage defines 'magma' as molten rock from the mantle.
Words from this passage worth keeping
topography(A)
the shape and physical features of the land
rifted(A)
split apart
brittle(B)
hard but easily broken
convection currents(B)
movements in a liquid or gas caused by heat rising
extrusions(C)
rock pushed out onto the surface
froth(C)
form a mass of small bubbles
irresistible(D)
too strong to be stopped
Sit this test on Langujet, then come back
The full Cambridge 4 Test 3 reading paper: all three passages, 60 minutes, marked the second you finish with a review of every answer. Already done it? Take it again and see if the same traps still get you.
Cambridge IELTS 4, Test 3, Reading Passage 2. The passage and questions belong to Cambridge University Press and are not reproduced here. We quote short extracts only as evidence for our own commentary, and the answers are published for self-marking. Get the book for the full text, or sit the test on Langujet.
