Living Dunes Reading Answers

Mar 4, 2023

Living Dunes Reading Answers is a general reading topic discussing in detail the sand dunes. The given IELTS topic has originated from the book named “A Book for IELTS.”. The topic named Living Dunes Reading Answers has a total of 13 questions. The topic consists of two sorts of questions, which are, choosing the correct heading, and choosing one word. The candidates should thoroughly read the IELTS reading passage to recognize the synonyms, identify the keywords, and answer the questions below. IELTS reading practice papers can be taken into consideration by the candidates in order to score a good score in the reading section in which similar topics like Living Dunes Reading Answers have been included.

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Section 1

Read the passage to answer the following questions

Living Dunes Reading Answers

When you think of a sand dune, you probably picture a barren pile of lifeless sand. But sand dunes are actually dynamic natural structures. They grow, shift and travel. They crawl with living things. Some sand dunes even sing.

Although no more than a pile of wind-blown sand, dunes can roll over trees and buildings, march relentlessly across highways, devour vehicles on its path, and threaten crops and factories in Africa, the Middle East, and China. In some places, killer dunes even roll in and swallow up towns. Entire villages have disappeared under the sand. In a few instances the government built new villages for those displaced only to find that new villages themselves were buried several years later. Preventing sand dunes from overwhelming cities and agricultural areas has become a priority for the United Nations Environment Program.
Some of the most significant experimental measurements on sand movement were performed by Ralph Bagnold, a British engineer who worked in Egypt prior to World War I. Bagnold investigated the physics of particles moving through the atmosphere and deposited by wind. He recognised two basic dune types, the crescentic dune, which he called "barchan" and the linear dune, which he called longitudinal or "sief' (Arabic for "sword"). The crescentic barchan dune is the most common type of sand dune. As its name suggests, this dune is shaped like oints at each end, and it is usually wider than it is long. Some types of barchan dunes move faster over desert surfaces than any other type of dune. The linear dune is straighter than the crescentic dune with ridges as its prominent feature. Unlike crescentic dunes, linear dunes are longer than they are wide-in fact, some are more than 100 miles (about 160 kilometers) long. Dunes can also be comprised of smaller dunes of different types, called complex a crescent moon with dunes.
Despite the complicated dynamics of dune formation, Bagnold noted that a sand dune generally needs the following three things to form: a large amount of loose sand in an area with little vegetation-usually on the coast or in a dried-up river, lake or sea bed; a wind or breeze to move the grains of sand and an obstacle, which could be as small as a rock or as big as a tree, that causes the sand to lose momentum and settle. Where these three variables merge, a sand dune forms.
As the wind picks up the sand, the sand travels, but generally only about an inch or two above the ground, until an obstacle causes it to stop. The heaviest grains settle against the obstacle, and a small ridge or bump forms. The lighter grains deposit themselves on the other side of the obstacle. Wind continues to move sand up to the top of the pile until the pile is so steep that it collapses under its own weight. The collapsing sand comes to rest when it reaches just the right steepness to keep the dune stable. The repeating cycle of sand inching up the windward side to the dune crest, then slipping down the dune's slip face allows the dune to inch forward, migrating in the direction the wind blows.
Depending on the speed and direction of the wind and the weight of the local sand, dunes will develop into different shapes and sizes. Stronger winds tend to make taller dunes; gentler winds tend to spread them out. If the direction of the wind generally is the same over the years, dunes gradually shift in that direction. But a dune is 'a curi-ously dynamic creature", wrote Farouk El-Baz in National Geographic. Once formed, a dune can grow, change shape, move with the wind and even breed new dunes. Some of these offspring may be carried on the back of the mother dune. Others are bom and race downwind, outpacing their parents.
Sand dunes even can be heard 'singing' in more than 30 locations worldwide, and in each place the sounds have their own characteristic frequency, or note. When the thirteenth century explorer Marco Polo encountered the weird and wonderful noises made by desert sand dunes, he attributed them to evil spirits. The sound is unearthly. The volume is also unnerving. Adding to the tones otherworldliness is the inability of the human ear to localise the source of the noise. Stéphane Douady of the French national research agency CNRS and his colleagues have been delving deeper into dunes in Morocco, Chile, China and Oman, and believe they can now explain the exact mechanism behind this acoustic phenomenon.
The group hauled sand back to the laboratory and set it up in channels with automated pushing plates. The sands still sang, proving that the dune itself was not needed to act as a resonating body for the sound, as some researchers had theorised. To make the booming sound, the grains have to be of a small range of sizes, all alike in shape: well-rounded. Douady's key discovery was that this synchronised frequency-which determines the tone of sound-is the result of the grain size. The larger the grain, the lower the key. He has successfully predicted the notes emitted by dunes in Morocco, Chile and the US simply by measuring the size of the grains they contain. Douady also discovered that the singing grains had some kind of varnish or a smooth coating of various minerals: silicon, iron and manganese, which probably formed on the sand when the dunes once lay beneath an ancient ocean. But in the muted grains this coat had been worn away, which explains why only some dunes can sing. He admits he is unsure exactly what role the coating plays in producing the noise. The mysterious dunes, it seems, aren't quite ready yet to give up all of their secrets.

Section 2

Solution and Explanation

Questions 27-33

Reading passage has seven paragraphs, A-G. Choose the correct heading for paragraphs A-G from the list of headings below. Write the correct number, i-x, in boxes 27-33 on your answer sheet.

List of Headings

Shaping and reforming
Causes of desertification
Need combination of specific conditions
Potential threat to industry and communication
An old superstition demystified
Differences and similarities
A continuous cycling process
Habitat for rare species
Replicating the process in laboratory
Commonest type of dune

Question 27. Paragraph A

Answer: iv
Supporting sentence: Although no more than a pile of wind-blown sand, dunes can roll over trees and buildings, march relentlessly across highways, devour vehicles on its path, and threaten crops
Keyword : wind-blown, sand, relentlessly, threaten crops
Keyword location: paragraph A, lines 1-3
Explanation: Lines 1-3 of paragraph A explain that while little more than a mound of wind-blown sand, dunes have the power to destroy farms. They can also destroy factories across China, the Middle East, and Africa. As the factories roll over trees and buildings, march mercilessly across highways, and devour any vehicles in their path. Killer dunes even sweep in and engulf villages in some locations.

Question 28. Paragraph B

Answer: x
Supporting sentence: The crescentic barchan dune is the most common type of sand dune.
Keyword : crescentic, barchan, common, sand dune
Keyword location: paragraph B, lines 5-6
Explanation: Lines 5-6 of paragraph B enhance that Ralph Bagnold distinguished between the crescentic dune, known as "barchan," and the linear dune. The most typical kind of sand dune is the crescentic barchan dune. This dune is formed like oints at each end, as its name implies, and it is typically broader than it is long.

Question 29. Paragraph C

Answer: iii
Supporting sentence: Bagnold noted that a sand dune generally needs the following three things to form
Keyword : Bagnold, sand dune, needs, three things
Keyword location: paragraph C, lines 1-2
Explanation: Lines 1-2 of paragraph C explain that despite the complex dynamics involved in dune development. Bagnold observed that the following three elements are often required for sand dunes to form. It is a significant amount of loose sand in a sparsely vegetated area, typically along the shore or in a dried-up river.

Question 30. Paragraph D

Answer: vii
Supporting sentence: Wind continues to move sand up to the top of the pile until the pile is so steep that it collapses under its own weight.
Keyword : Wind, continues, sand up, collapses
Keyword location: paragraph D, lines 4-5
Explanation: Lines 4-5 of paragraph D suggest that the largest grains accumulate against the obstruction, forming a tiny ridge or bump. On the other side of the obstruction, the lighter grains settle. Sand is continuously added to the top of the pile by the wind until the mound becomes so steep that it topples over under its own weight.

Question 31. Paragraph E

Answer: i
Supporting sentence: Depending on the speed and direction of the wind and the weight of the local sand, dunes will develop into different shapes and sizes.
Keyword : Depending, speed, wind and the weight, shapes and sizes
Keyword location: paragraph E, lines 1-2
Explanation: Lines 1-2 of paragraph E explains that dunes can take on a variety of shapes and sizes depending on the wind's strength and direction. They can also take on the density of the surrounding sand. Stronger winds tend to create dunes that are taller, whereas softer winds spread them out. Dunes gradually move in that direction if the wind blows in that general direction over time.

Question 32. Paragraph F

Answer: v
Supporting sentence: When the thirteenth-century explorer Marco Polo encountered the weird and wonderful noises made by desert sand dunes, he attributed them to evil spirits.
Keyword : thirteenth-century, Marco Polo, dunes, evil spirits
Keyword location: paragraph F, lines 2-4
Explanation: Lines 2-4 of paragraph F imply that at more than 30 spots throughout the world. Sand dunes can even be heard "singing," with each region having its own distinctive frequency or tone. The strange and amazing noises generated by desert sand dunes were first heard by Marco Polo in the thirteenth century, who attributed them to demonic spirits.

Question 33. Paragraph G

Answer: ix
Supporting sentence: The group hauled sand back to the laboratory and set it up in channels with automated pushing plates.
Keyword : group, hauled, automated, pushing plates
Keyword location: paragraph G, lines 1-2
Explanation: Lines 1-2 of paragraph G describe that the team transported sand back to the lab, where it was arranged in channels with mechanical pushing plates. The sands continued to sing, disproving earlier theories
that the dune itself served as a resonant body for the song.

Questions 34-36

Choose ONE WORD ONLY from the passage for each answer

(34).......... dune is said to have long ridges that can extend hundreds of miles.

According to Bagnold, an (35).......... is needed to stop the sand from moving before a dune can

form.

Stéphane Douady believes the singing of dunes is not a spiritual phenomenon, but purely (36)............

Question 34:

Answer: linear
Supporting sentence: Unlike crescentic dunes, linear dunes are longer than they are wide-in fact, some are more than 100 miles (about 160 kilometers) long.
Keyword : linear dunes, wide, more, 100 miles
Keyword location: paragraph B, lines 9-11
Explanation: Lines 9-11 of paragraph B explain that the ridges are the main characteristic of the linear dune. The linear dune is straighter than the crescentic dune. Contrary to crescentic dunes, linear dunes are wider than they are long; in fact, some of them reach lengths of more than 100 miles (160 kilometers).

Question 35:

Answer: obstacle
Supporting sentence: a wind or breeze to move the grains of sand and an obstacle
Keyword : wind, breeze, sand, an obstacle
Keyword location: paragraph C, lines 3-6
Explanation: Lines 3-6 of paragraph C explain that a breeze or wind moves the sand grains and is an obstruction. It could be as little as a rock or as large as a tree, to slow the sand down and cause it to settle. A sand dune develops where these three factors come together.

Question 36:

Answer: acoustic
Supporting sentence: the exact mechanism behind this acoustic phenomenon
Keyword : exact, mechanism, acoustic, phenomenon
Keyword location: paragraph F, lines 7-8
Explanation: Lines 7-8 of paragraph F suggest that after doing extensive research on dunes in Morocco, Chile, China, and Oman. They can do so by underlying this auditory occurrence.

Questions 37-40

Choose ONE WORD ONLY from the passage for each answer.

There are many different types of dunes, two of which are most commonly found in deserts throughout the world, the linear dune and the (37)........... dune, some times also known as the crescentic dune.

It's been long known that in some places dunes can even sing and the answer lies in the sand itself. To produce singing sand in lab, all the sands must have similar (38).........

And scientists have discovered that the size of the sand can affect the (39)........... of the sound. But the function of the varnish composed by a mixture of (40)........... still remains puzzling.

Question 37:

Answer: barchan
Supporting sentence: He recognized two basic dune types, the crescentic dune, which he called "barchan"
Keyword : recognized, dune, crescentic, barchan
Keyword location: paragraph B, line 4
Explanation: The fourth line of paragraph B suggests that the crescentic dune, which he termed "barchan". Also, the linear dune, which he called longitudinal or "sief," were the two primary types of dunes that he recognised
(Arabic for "sword"). Sand dunes are most frequently found as crescentic barchan dunes.

Question 38:

Answer: shape
Supporting sentence: To make the booming sound, the grains have to be of a small range of sizes, all alike in shape: well-rounded.
Keyword : booming, sound, shape, well-rounded
Keyword location: paragraph G, lines 3-4
Explanation: Lines 3-4 of paragraph G describe that the sands continued to sing, disproving earlier theories that the dune itself served as a resonant body for the song. The grains must all have the same shape—well-rounded—and a narrow range of sizes in order to produce the booming sound.

Question 39:

Answer: tone
Supporting sentence: Douady's key discovery was that this synchronized frequency-which determines the tone of sound-is the result of the grain size.
Keyword : synchronized, determines, tone, sound
Keyword location: paragraph G, lines 5-6
Explanation: Lines 5-6 of paragraph G suggest that the grains must all have the same shape. It will be well-rounded and have a narrow range of sizes in order to produce the booming sound. The main finding by Douady was that the grain size is what causes this synchronized frequency, which defines the tone of the sound.

Question 40:

Answer: minerals
Supporting sentence: Douady also discovered that the singing grains had some kind of varnish or a smooth coating of various minerals
Keyword : Douady, grains, varnish, minerals
Keyword location: paragraph G, lines 8-9
Explanation: Lines 8-9 of paragraph G explain that Douady also found that the singing grains had a smooth layer of several minerals. It includes silicon, iron, and manganese, which most likely developed on the sand when the dunes were under an old ocean.