Silent Earthquake Reading Answers

Jan 13, 2023

Silent Earthquake Reading Answers contains a write up about the silent earthquake and its occurrence reasons. Silent Earthquake Reading Answers contains a total of 10 paragraphs. Related to the paragraphs are 13 questions. Candidates in this IELTS Section will be shown various question types with clear instructions. The paragraphs discrete the silent earthquake and its occurrence reasons. Also, the effects of these earthquakes.

Silent Earthquake Reading Answers is an IELTS Reading passage which comprises three types of questions: Choose the correct option, true/false and not given and Complete the summary. To complete the summary candidate must be aware of each detail mentioned. The paragraphs must be read thoroughly and important details remembered. So. A deep understanding of paragraphs is required. Some information might be missing from paragraphs which need to be mentioned as not given. To choose the correct option the information in paragraphs must be remembered. To gain proficiency, candidates can practice from IELTS reading practice test.

Check: Get 10 Free IELTS Sample Papers
Check: Register for IELTS Coaching - Join for Free Trial Class Now

Section 1

Read the Passage to Answer the Following Questions

Silent Earthquake Reading Answers

In early November 2000 the Big Island of Hawaii experienced its largest earthquake in more than a decade. Some 2,000 cubic kilometers of the southern slope of the Kilauea volcano lurched toward the ocean, releasing the energy of a magnitude 5.7 shock. Part of that motion took place under an area where thousands of people stop every day to catch a glimpse of one of the island's most spectacular lava flows. Yet when the earthquake struck, no one noticed-not even seismologists.

How could such a notable event be overlooked? As it turns out, quaking is not an intrinsic part of all earthquakes. The event on Kilauea was one of the first unambiguous records of a so-called silent earthquake, a type of massive earth movement unknown to science until just a few years ago. Indeed, I would never have discovered this quake if my colleagues at the U.S. Geological Survey's Hawaiian Volcano Observatory had not already been using a network of sensitive instruments to monitor the volcano's activity.
When I finally noticed that Kilauea's south flank had shifted 10 centimeters along an underground fault, I also saw that this movement had taken nearly 36 hours-a turtle's pace for an earthquake. In a typical tremor, opposite sides of the fault rocket pass each other in a matter of seconds -quickly enough to create the seismic waves that cause the ground to rumble and shake.

But just because an earthquake happens slowly and quietly does not make it insignificant. My co-investigators and I realized immediately that Kilauea's silent earthquake could be a harbinger of disaster. If that same large body of rock and debris were to gain momentum and take the form of a gigantic landslide-separating itself from the rest of the volcano and sliding rapidly into the sea-the consequences would be devastating. The collapsing material would push seawater into towering tsunami waves that could threaten coastal cities along the entire Pacific Rim. Such catastrophic flank failure, as geologists call it, is a potential threat around many island volcanoes worldwide.

Fortunately, the discovery of silent earthquakes is revealing more good news than bad. The chances of catastrophic flank failure are slim, and the instruments that record silent earthquakes might make early warnings possible. New evidence for conditions that might trigger silent slip suggests bold strategies for preventing flank collapse. Occurrences of silent earthquakes are also being reported in areas where flank failure is not an issue. Their silent earthquakes are inspiring ways to improve the forecasts of their ground-shaking counterparts.

The discovery of silent earthquakes and their link to catastrophic flank collapse was a by-product of efforts to study other potential natural hazards. Destructive earthquakes and volcanoes are a concern in Japan and the U.S. Pacific Northwest, where tectonic plates constantly plunge deep into the earth along what are called subduction zones.
Beginning in the early 1990s, geologists began deploying large networks of continuously recording Global Positioning System (GPS) receivers in these regions and along the slopes of active volcanoes, such as Kilauea. By receiving signals from a constellation of more than 30 navigational satellites, these instruments can measure their own positions on the planet's surface at any given time to within a few millimeters.

The scientists who deployed these GPS receivers expected to see both the slow, relentless motion of the planet's shell of tectonic plates and the relatively quick movements that earthquakes and volcanoes trigger. It came as some surprise when these instruments detected small ground movements that were not associated with any known earthquake or eruption. When researchers plotted the ground movements on a map, the pattern that resulted very much resembled one characteristic of fault movement. In other words, all the GPS stations on one side of a given fault moved several centimeters in the same general direction.
This pattern would have been no surprise if it had taken a year or longer to form.
In that case, scientists would have known that a slow and steady process called fault creep was responsible. But at rates of up to centimeters a day, the mystery events were hundreds of times as fast as that. Beyond their relative speediness, these silent earthquakes shared another attribute with their noisy counterparts that distinguished them from fault creep: they are not steady processes but instead are discrete events that begin and end suddenly.

That sudden beginning, when it takes place on the slopes of a volcanic island, creates concern about a possible catastrophic flank event. Most typical earthquakes happen along faults that have built-in brakes: motion stops once the stress is relieved between the two chunks of earth that are trying to move past each other. But activity may not stop if gravity becomes the primary driver. In the worst-case scenario, the section of the volcano lying above the fault becomes so unstable that once slip starts, gravity pulls the entire mountainside downhill until it disintegrates into a pile of debris on the ocean floor.

The slopes of volcanoes such as Kilauea become steep and vulnerable to this kind of collapse when the lava from repeated eruptions builds them up more rapidly than they can erode away. Discovering the silent earthquake on Kilauea suggests that the volcano's south flank is on the move, perhaps on its way to eventual obliteration.

For now, friction along the fault is acting as an emergency brake. But gravity has won out in many other instances in the past. Scientists have long seen evidence of ancient collapses in sonar images of giant debris fields in the shallow waters surrounding volcanic islands around the world, including Majorca in the Mediterranean Sea and the Canary Islands in the Atlantic Ocean. In the Hawaiian Islands, geologists have found more than 25 individual collapses that have occurred over the past five million years-the blink of an eye in geologic time.

In a typical slide, the volume of material that enters the ocean is hundreds of times as great as the section of Mount St. Helens that blew apart during the 1980 eruption-more than enough to have triggered immense tsunamis. On the Hawaiian island of Lanai, for instance, geologists discovered evidence of wave action, including abundant marine shell fragments, at elevations of 325 meters.
Gary M. McMurtry of the University of Hawaii at Manoa and his colleagues conclude that the most likely way the shells could have reached such a lofty location was within the waves of a tsunami that attained the astonishing height of 300 meters along some Hawaiian coastlines. Most of the tallest waves recorded in modern times were no more than one-tenth that size.

Section 2

Solution and Explanation

Questions 1-5

Do the following statements agree with the information given IN IELTS Reading Test

TRUE if the statement is true
FALSE if the statement is false
NOT GIVEN If the information is not given in the passage

It takes a quite fast interaction caused by certain parts of the fault zone to produce a representative earthquake.

Answer: True
Supporting Statement: In a typical tremor, opposite sides of the fault rocket pass each other in a matter of seconds -quickly enough to create the seismic waves that cause the ground to rumble and shake.
Keyword : Typical tremor
Keyword Location: Paragraph C
Explanation: As per paragraph C, In a typical tremor, the fault's opposing sides pass each other swiftly enough to generate the seismic waves that cause the earth to tremble and quake. Thus, the statement is True.

Flank failure is a prerequisite that is followed by a silent earthquake.

Answer: False
Supporting Statement: New evidence for conditions that might trigger silent slip suggests bold strategies for preventing flank collapse. Occurrences of silent earthquakes are also being reported in areas where flank failure is not an issue. Their silent earthquakes are inspiring ways to improve the forecasts of their ground-shaking counterparts.
Keyword : Flank failure, shaking
Keyword Location: Paragraph D
Explanation: As per paragraph D, Bold techniques for averting flank collapse are suggested by new evidence for circumstances that could cause quiet slide. In locations where flank failure is not a problem, reports of silent earthquakes have also been made. Their quiet earthquakes provide ideas for how to make ground-shaking counterparts' forecasts more accurate. Thus, the statement is False.

The silent earthquake can be used to forecast any form of an earthquake.

Answer: Not Given
Explanation: There has been no relevant information provided related to the question statement in the paragraph. So, the answer is Not Given.

Kilauea falls into the category of stirring volcanoes.

Answer: True
Supporting Statement: When I finally noticed that Kilauea's south flank had shifted 10 centimeters along an underground fault, I also saw that this movement had taken nearly 36 hours-a turtle's pace for an earthquake. In a typical tremor, opposite sides of the fault rocket pass each other in a matter of seconds -quickly enough to create the seismic waves that cause the ground to rumble and shake.
Keyword : Sounds-quickly, the seismic waves.
Keyword Location: Paragraph B
Explanation: As per paragraph B, the Kilauea falls in the category of stirring volcanoes. In a typical tremor, the fault's opposing sides pass each other swiftly enough to generate the seismic waves that cause the earth to tremble and quake. So, the statement is True.

In some islands, no less than 25 independent dilapidations are noticed in a short period from the perspective of geology.

Answer: True
Supporting Statement: In the Hawaiian Islands, geologists have found more than 25 individual collapses that have occurred over the past five million years-the blink of an eye in geologic time.
Keyword : Geologist, Hawaiian islands
Keyword Location: Paragraph I
Explanation: As per paragraph I, Over the past five million years a mere blink of an eye in geologic time geologists have discovered more than 25 distinct collapses in the Hawaiian Islands. So, the statement is True.

Questions 6-10

The reading Passage has seven paragraphs A-H.

Which paragraph contains the following information?

NB You may use any letter more than once.

the main characteristic to differentiate fault creep from earthquakes

Answer: F
Supporting Statement: When researchers plotted the ground movements on a map, the pattern that resulted very much resembled one characteristic of fault movement. In other words, all the GPS stations on one side of a
given fault moved several centimeters in the same general direction.
Keyword : Fault movement
Keyword Location: Paragraph F
Explanation: As per paragraph F, the fault movement was generated by a well plotted ground movement map. The pattern that emerged when the ground motions were plotted on a map closely resembled a fault movement characteristic. So, the correct answer is F.

occurrence of landslide in water areas near volcanoes in archaic times

Answer: I
Supporting Statement: For now, friction along the fault is acting as an emergency brake. But gravity has won out in many other instances in the past. Scientists have long seen evidence of ancient collapses in sonar images of giant debris fields in the shallow waters surrounding volcanic islands around the world, including Majorca in the Mediterranean Sea and the Canary Islands in the Atlantic Ocean
Keyword : Shallow waters, volcanic islands
Keyword Location: Paragraph I
Explanation: As per paragraph I, The Canary Islands in the Atlantic Ocean and Majorca in the Mediterranean Sea both show ancient collapses in sonar photos of massive debris fields inside the shallow waters encircling volcanic islands. So, the correct answer is I.

catastrophe caused by a silent earthquake under certain circumstances

Answer: C
Supporting Statement: The collapsing material would push seawater into towering tsunami waves that could threaten coastal cities along the entire Pacific Rim. Such catastrophic flank failure, as geologists call it, is a potential threat around many island volcanoes worldwide.
Keyword : Collapsing material, catastrophic flank
Keyword Location: Paragraph C
Explanation: As per paragraph C, Seawater would be forced into enormous tsunami waves by the collapsing material, endangering coastal cities all along the Pacific Rim. Geologists refer to this catastrophic flank failure as a possible threat that exists near many island volcanoes throughout the world. So, the correct answer is C.

a metaphor to describe how slow a silent earthquake takes place

Answer: B
Supporting Statement: As it turns out, quaking is not an intrinsic part of all earthquakes. The event on Kilauea was one of the first unambiguous records of a so-called silent earthquake, a type of massive earth movement unknown to science until just a few years ago.
Keyword : Unambiguous records
Keyword Location: Paragraph B
Explanation: As per paragraph B, it has been clearly mentioned that quaking is not a necessary component of every earthquake. Kilauea's eruption was one of the first instances of a silent earthquake, a form of powerful earth tremor that was previously unknown to science. So, the correct answer is B.

the possible ending for the south slope of Kilauea

Answer: H
Supporting Statement: The slopes of volcanoes such as Kilauea become steep and vulnerable to this kind of collapse when the lava from repeated eruptions builds them up more rapidly than they can erode away.
Discovering the silent earthquake on Kilauea suggests that the volcano's south flank is on the move, perhaps on its way to eventual obliteration
Keyword : Slopes of volcanoes, Kilauea
Keyword Location: Paragraph H
Explanation: As per paragraph H, When the lava from successive eruptions builds up on the slopes of volcanoes like Kilauea more quickly than they can be worn away by erosion, the slopes grow steep and susceptible to this type of collapse. So, the correct answer is .

Questions 11-13

Complete the following summary of the paragraphs using no more than two words or a number from the Reading Passage for each.

When a model slide happens, the amount of the parts flowing into the sea is so huge that it might bring about ........11...... Ample shell debris included in........12...... is a good example because they might be moved to the high area by currents. This height of the waves is as ......13... times taller than that documented in the contemporary era.

Question 11)

Answer: Immense Tsunamis
Supporting Statement: In a typical slide, the volume of material that enters the ocean is hundreds of times as great as the section of Mount St. Helens that blew apart during the 1980 eruption-more than enough to have
triggered immense tsunamis
Keyword : Immense tsunamis, eruption
Keyword Location: Paragraph J
Explanation: As per paragraph J, it has been mentioned that the amount of debris that enters the water during a typical slide is hundreds of times greater than the amount that blasted apart during the 1980 eruption of Mount St. Helens, more than enough to have caused enormous tsunamis. So, the correct answer is immense tsunamis.

Question 12)

Answer: Wave actions
Supporting Statement: On the Hawaiian island of Lanai, for instance, geologists discovered evidence of wave action, including abundant marine shell fragments, at elevations of 325 meters.
Keyword : Hawaiian Island, wave action
Keyword Location: Paragraph J
Explanation: As per paragraph J, the correct answer is Wave action. Because geologists found evidence of wave action on the Hawaiian island of Lanai at elevations of 325 meters, including a lot of marine shell pieces.

Question 13)

Answer: one-tenth
Supporting Statement: Most of the tallest waves recorded in modern times were no more than one-tenth that size.
Keyword : Tallest waves, modern times
Keyword Location: Paragraph J
Explanation: As per paragraph J, One- tenth of that size separated the majority of the biggest waves observed in recent times.

Read More IELTS Reading Related Samples