Scattered around the globe are more than one hundred regions of volcan

Question

Scattered around the globe are more than one hundred regions of volcanic activity known as hot spots. Unlike most volcanoes, hot spots are rarely found along the boundaries of the continental and oceanic plates that comprise the Earth’s crust; most hot spots lie deep in the interior of plates and are anchored deep in the layers of the Earth’s surface. Hot spots are also distinguished from other volcanoes by their lavas, which contain greater amounts of alkali metals than do those from volcanoes at plate margins.

In some cases, plates moving past hot spots have left trails of extinct volcanoes in much the same way that wind passing over a chimney carries off puffs of smoke. It appears that the Hawaiian Islands were created in such a manner by a single source of lava, welling up from a hot spot, over which the Pacific Ocean plate passed on a course roughly from the east toward the northwest, carrying off a line of volcanoes of increasing age. Two other Pacific island chains—the Austral Ridge and the Tuamotu Ridge—parallel the configuration of the Hawaiian chain; they are also aligned from the east toward the northwest, with the most recent volcanic activity near their eastern terminuses.

That the Pacific plate and the other plates are moving is now beyond dispute; the relative motion of the plates has been reconstructed in detail. However, the relative motion of the plates with respect to the Earth’s interior cannot be determined easily. Hot spots provide the measuring instruments for resolving the question of whether two continental plates are moving in opposite directions or whether one is stationary and the other is drifting away from it. The most compelling evidence that a continental plate is stationary is that, at some hot spots, lavas of several ages are superposed instead of being spread out in chronological sequence. Of course, reconstruction of plate motion from the tracks of hot-spot volcanoes assumes that hot spots are immobile, or nearly so. Several studies support such an assumption, including one that has shown that prominent hot spots throughout the world seem not to have moved during the past ten million years.

Beyond acting as frames of reference, hot spots apparently influence the geophysical processes that propel the plates across the globe. When a continental plate comes to rest over a hot spot, material welling up from deeper layers forms a broad dome that, as it grows, develops deep fissures. In some instances, the continental plate may rupture entirely along some of the fissures so that the hot spot initiates the formation of a new ocean. Thus, just as earlier theories have explained the mobility of the continental plates, so hot-spot activity may suggest a theory to explain their mutability.    1 
 1. The primary purpose of the passage is to

(A) describe the way in which hot spots influence the extinction of volcanoes
(B) describe and explain the formation of the oceans and continents
(C) explain how to estimate the age of lava flows from extinct volcanoes
(D) describe hot spots and explain how they appear to influence and record the motion of plates
(E) describe the formation and orientation of island chains in the Pacific Ocean

2 
 2. According to the passage, hot spots differ from most volcanoes in that hot spots

(A) can only be found near islands
(B) are active whereas all other volcanoes are extinct
(C) are situated closer to the earth’s surface
(D) can be found along the edges of the plates
(E) have greater amounts of alkali metals in their lavas

3 
 3. It can be inferred from the passage that evidence for the apparent course of the Pacific plate has been provided by the

(A) contours of the continents
(B) dimensions of ocean hot spots
(C) concurrent movement of two hot spots
(D) pattern of fissures in the ocean floor
(E) configurations of several mid-ocean island chains

4 
 4. It can be inferred from the passage that the spreading out of lavas of different ages at hot spots indicates that a

(A) hot spot is active
(B) continental plate has moved
(C) continental rupture is imminent
(D) hot spot had been moving very rapidly
(E) volcano contains large concentrations of alkali metals

5 
 5. The passage suggests which of the following about the Hawaiian Islands, the Austral Ridge, and the Tuamotu Ridge?

(A) The three chains of islands are moving eastward.
(B) All the islands in the three chains have stopped moving.
(C) The three island chains are a result of the same plate movement.
(D) The Hawaiian Islands are receding from the other two island chains at a relatively rapid rate.
(E) The Austral Ridge and the Tuamotu Ridge chains have moved closer together whereas the Hawaiian Islands have remained stationary.

6 
 6. Which of the following, if true, would best support the author’s statement that hot-spot activity may explain the mutability of continental plates?

(A) Hot spots move more rapidly than the continental and oceanic plates.
(B) Hot spots are reliable indicators of the age of continental plates.
(C) Hot spots are regions of volcanic activity found only in the interiors of the continental plates.
(D) The alignment of hot spots in the Pacific Ocean parallels the alignment of Pacific Ocean islands.
(E) The coastlines of Africa and South America suggest that they may once have constituted a single continent that ruptured along a line of hot spots.

7 
 7. The author’s argument that hot spots can be used to reconstruct the movement of continental plates is weakened by the fact that

(A) hot spots are never found at the boundaries of plates
(B) only extinct volcanoes remain after a plate moves over a hot spot
(C) lava flow patterns for all hot spots have not been shown to be the same
(D) the immobility or near immobility of hot spots has not been conclusively proven
(E) the changing configurations of islands make pinpointing the locations of hot spots difficult

8 
 8. The author’s style can best be described as

(A) dramatic
(B) archaic
(C) esoteric
(D) objective
(E) humanistic

RC Butler 2021  -  Practice Two RC Questions Everyday.   
Passage # 79 Date: 25-Feb-2021
 This question is a part of RC Butler 2021 .  Click here for Details

Chinmay1502 · Answer

Sajjad1994 , can you please explain Q.5?

Sajjad1994 · Answer

Explanation

5. The passage suggests which of the following about the Hawaiian Islands, the Austral Ridge, and the Tuamotu Ridge?

Difficulty Level:   600

Explanation

We cannot memorize the whole passage and we have even no need of it, the good trick here is to get a gist of the passage within the minimum possible time and go back to the passage for each of the questions. Question #5 is not that thought it is maximum a medium level (600-level) difficult. To get this question right, read and understand the  second paragraph  completely.

In some cases, plates moving past hot spots have left trails of extinct volcanoes in much the  same way  that wind passing over a chimney carries off puffs of smoke. It appears that the  Hawaiian Islands were created in such a manner by a single source of lava , welling up from a hot spot, over which the Pacific Ocean plate passed on a course roughly from the east toward the northwest, carrying off a line of volcanoes of increasing age.  Two other Pacific island chains—the Austral Ridge and the Tuamotu Ridge —parallel the configuration of the Hawaiian chain; they  are also  aligned from the  east toward the northwest , with the most recent volcanic activity near their eastern terminuses.

Read the answer choices

(A)  The three chains of islands are moving eastward.
Opposite

(B)  All the islands in the three chains have  stopped moving. 
Out of the scope of the passage

(C) The three island chains are a result of the same plate movement. 
Correct as according to the text referred above.

(D)  The Hawaiian Islands are  receding from the other two island chains  at a relatively  rapid rate. 
This option provides information that is outside of the scope of this question.

(E)  The Austral Ridge and the Tuamotu Ridge chains have  moved closer  together whereas the Hawaiian Islands have  remained stationary.

Same as D, it is also out of the scope.

Answer: C

zyoNe · Answer

Yeah, my RC is also fine, but I read the passage over and over again to understand what it trying to explain and figure.

Akarshkhan86 · Answer

Hello  Sajjad1994

Can you share the OE of Question 6, if possible, because I am confused how to eliminate option D out.
Also, if you can share OE for Question8?

Sajjad1994 · Answer

Hello Akarshkhan86

OE is not available.

To answer question number 6, one needs to identify the correct part of the passage the question is referring to. The question is talking about the text in the third paragraph:

This is the question:
 "Hot spots provide the measuring instruments for resolving the question of whether two continental plates are moving in opposite directions or whether one is stationary and the other is drifting away from it."

This statement needs to be strengthened:
"The most compelling evidence that a continental plate is stationary is that, at some hot spots, lavas of several ages are superposed instead of being spread out in chronological sequence."

Now we have to find an answer choice which, if true, would strengthen the above statement by the author. Only  option (E)  is most suitable.

Sajjad1994 · Answer

The statement of question #8 is GMAT-style but the answer choices are GRE-style. Although I selected D as the answer I don't know the meaning of (B) archaic and (C) esoteric. I selected D from three choices that are A, D, and E. GMAT doesn't ask vocabulary-heavy questions so don't worry about this question as I assume this passage belongs to GRE material though I don't know exactly.

JYOTISI · Answer

Can someone please explain question no. 3 and 7

Posted from my mobile device

Sajjad1994 · Answer

Explanation

3. It can be inferred from the passage that evidence for the apparent course of the Pacific plate has been provided by the

Difficulty Level:  705

Explanation The passage discusses the phenomenon of hot spots and their significance in understanding the movement of tectonic plates, particularly focusing on the Pacific plate.

(A)  The passage doesn't directly mention evidence provided by the contours of continents in determining the course of the Pacific plate.

(B)  The passage discusses hot spots but doesn't mention using their dimensions as evidence for the course of the Pacific plate.

(C)  The passage doesn't discuss the concurrent movement of two hot spots as evidence for the course of the Pacific plate.

(D)  The passage mentions that when a continental plate comes to rest over a hot spot, material welling up from deeper layers forms fissures in the continental plate. While this is related to the influence of hot spots on tectonic activity, it doesn't directly provide evidence for the course of the Pacific plate.

(E)   The passage discusses the Hawaiian Islands, Austral Ridge, and Tuamotu Ridge, which are aligned in a specific direction, indicating the apparent course of the Pacific plate. This aligning of mid-ocean island chains suggests the movement of the Pacific plate over a hot spot, providing evidence for its course.

Answer: E

Sajjad1994 · Answer

Explanation

7. The author’s argument that hot spots can be used to reconstruct the movement of continental plates is weakened by the fact that

Difficulty Level:   555

Explanation

The author argues that hot spots can be used to reconstruct the movement of continental plates. They provide evidence for this claim by stating that hot spots are relatively stationary and that the lava flows from hot spots create distinct patterns, such as the trail of extinct volcanoes left behind as plates move over them. The author also acknowledges that the assumption of hot spots being immobile is essential for reconstructing plate motion.

(A)  This statement actually supports the author's argument because it reinforces the idea that hot spots are located within plates, making them useful reference points for plate movement.

(B)  This statement aligns with the author's argument, as it describes one of the observable effects of plate movement over hot spots, thus reinforcing the idea that hot spots can be used to reconstruct plate motion.

(C)  While this statement might introduce variability in the use of hot spots as reference points for plate motion, it doesn't directly weaken the author's argument, as the focus is on the general concept of hot spots being used for reconstruction, not on the uniformity of lava flow patterns.

(D)   This statement directly weakens the author's argument. If the immobility of hot spots cannot be conclusively proven, then the assumption underlying the reconstruction of plate motion—that hot spots are stationary—becomes less reliable.

(E)  While this statement may introduce practical challenges in pinpointing the exact locations of hot spots, it doesn't directly weaken the author's argument about using hot spots as reference points for plate motion reconstruction.

Answer: D

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Scattered around the globe are more than one hundred regions of volcan

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Scattered around the globe are more than one hundred regions of volcan

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