Reading comp PrepTest 132 · Section 1 · Question 3

Passage

Questions 1-8  .        To study centuries-old earthquakes and the geologic  . faults that caused them, seismologists usually dig  . Remaining source text redacted.
Passage walkthrough
Passage Summary

Topic: Science


Paragraph 1

  • Paragraph note
    • Traditional approach to dating earthquakes (radiocarbon dating of carbon 14 isotopes in organic material near faults)
  • Views, minor Meta-Structures, and the author's attitude
    • Old approach:
      • Radiocarbon dating (of carbon 14 isotopes) of organic material trapped in sediments that show evidence of having shifted near fault lines (first through third sentence)
      • This can show the location and frequency of past earthquakes and the likelihood of future earthquakes (last sentence)

Paragraph 2

  • Paragraph note
    • New approach to dating earthquakes (lichenometry — measuring lichen growth along rocks)
  • Views, minor Meta-Structures, and the author's attitude
    • New approach:
      • Bull and Brandon developed lichenometry, which involves measuring lichen growth along rocks exposed by rockfalls following earthquakes (first through fourth sentences)
      • The number of rockfalls can show how strong the earthquake was and the location of rockfalls can help map the earthquake's epicenter (seventh and last sentences)
    • Example of lichen's slow and steady growth:
      • North American lichen, which grows 9.5 mm/year (fifth sentence)
    • Author's attitude: "provides direct evidence" (sixth sentence); "would imply" (seventh sentence); "can then be determined" (last sentence)

Paragraph 3

  • Paragraph note
    • Author on disadvantages of radiocarbon dating (not accurate in last 300 years, as the environment affects isotopes) and Bull/Brandon's requirements for lichenometry (minimize/factor disturbances like snow, shade, wind)
  • Views, minor Meta-Structures, and the author's attitude
    • Author's view:
      • Lichenometry has distinct advantages over radiocarbon dating, the latter of which is only accurate to within +/- 40 years and not of much use in the past 300 years (first through third sentences)
    • Bull and Brandon's view:
      • Lichenometry is accurate to within +/- 10 years and best in the past 500 years, but one needs to take into account the factors that can speed or slow lichen growth, like snow, wind, and shade (fifth through last sentences)
    • Cause-and-effect relationships:
      • Radiation on the Earth's upper atmosphere causes the amount of carbon 14 isotope to vary (second sentence)
      • Heavy radiation fluctuation in the last 300 years causes radiocarbon dating during this era to be useless (third sentence)
      • Snow avalanches and other disturbances can cause lichen growth to slow down (last sentence)
      • Shade and wind causes lichen growth to speed up (last sentence)
    • Author's attitude: "distinct advantages" (first sentence); "accurate only to within plus or minus 40 years" (second sentence); "fluctuated greatly" (third sentence); "of little value" (third sentence)

Main Point: Even though it requires careful site selection and calibration, lichenometry, a new technique for dating past earthquakes, has several advantages over the traditional radiocarbon dating technique.

Meta-Structure?

OldApproach/New Approach: This passage fits the Old Approach/New Approach Meta-Structure like a glove. In such a passage, the author will typically start by describing an old way of doing something or thinking about something. Often, this is referred to as the "traditional" approach or theory). The author will then describe a new, alternative way of doing or thinking about that same thing. Usually, the author prefers the new approach.

That's what happens here. The author introduces the "usual[]" technique in the first paragraph before shifting to the new technique in the second. When a passage utilizes this Old Approach/New Approach Meta-Structure, the author's opinion on the new approach is usually the main point. Here, the author feels that it has "distinct advantages" over the old technique, so we should ground our understanding of the main point in that view.

Last Thoughts?

Be careful with the end of this passage, starting in the fifth sentence of the last paragraph (beginning with "They note"). The author pivots here, stating that Bull and Brandon note some limitations on lichenometry — careful site selection and calibration. However, that doesn't undercut the author's claim that lichenometry has "distinct advantages" over radiocarbon dating, so we shouldn't feel as if this section is enough to make the author want to abandon the practice. That opening line of the third paragraph is still the clearest statement of the author's opinion.

Question prompt

What is the author's Remaining source text redacted.
Why the credited answer is right

Credited answer: E

The notes below walk through why it fits the stem and how to eliminate the rest.

Question Type

Science

Strategy Overview

Review the reference to the rate of growth of a North American lichen species, consult notes, and choose an answer choice based on your understanding of that reference in the passage's overall argument

Answer Anticipation

This question asks us why the author inserted the discussion of a North American lichen species's rate of growth into the second paragraph. Unless a detail conflicts with the paragraph's purpose, the author probably mentioned that detail to advance the paragraph's role. So, reviewing the second paragraph's role, which we hopefully wrote down in the notes on our scratch paper, will generally reveal why the author included that detail.Our note for the second paragraph is, "New approach to dating earthquakes (lichenometry — measuring lichen growth along rocks)." So, that paragraph is where the author describes the new technique to date past earthquakes — lichenometry. As such, the author probably mentioned a North American lichen species's growth rate to help explain something about something about this technique.Heading to the lines in question, the sentence starts a little past halfway through the paragraph. The American lichen species is called an "example" (P1, S5). So, we need to see what it's an example of. Heading to the previous sentence to check that, we can see that it discusses what lichens are and how they grow at a "slow but constant rate" for as long as 1,000 years (P1, S4). The North American lichen is presented as an example of this, and it notes that it grows at the pace of 9.5mm per 100 years (even if you don't know the metric system, you should know that millimeters are small, and thus this is a slow pace). So, this example is meant to illustrate the slow growth of lichen. Let's find an answer stating that.

Answer choices

  1. A
    to emphasize the rapidity Remaining source text redacted.
    Why choice A is not credited

    (A) Does this say the North American lichen species is an example meant to illustrate how slowly lichen grows?

    Nope. The information about the North American lichen is its growth rate, not how quickly it starts to grow on a new rock surface, so this answer is off. It's tempting because the previous sentence does bring up the quickness with which lichen colonizes such surfaces (P1, S4), but the actual information presented about the North American lichen doesn't discuss this aspect of the previous sentence.

  2. B
    to offer an example Remaining source text redacted.
    Why choice B is not credited

    (B) Does this say the North American lichen species is an example meant to illustrate how slowly lichen grows?

    Not quite. While this growth rate seems pretty slow, there's no comparison between it and other types of lichen, so this comparative answer ("one of the slowest") is unsupported.

  3. C
    to present additional evidence Remaining source text redacted.
    Why choice C is not credited

    (C) Does this say the North American lichen species is an example meant to illustrate how slowly lichen grows?

    No. The second paragraph talks about the "slow but constant" growth rate of lichen. It's not until the last sentence of the passage that environmental conditions are noted that can alter this growth rate. So, this information in the second paragraph can't be meant to present "additional evidence" supporting a contention that isn't made until the end of the passage.

  4. D
    to explain why lichenometry Remaining source text redacted.
    Why choice D is not credited

    (D) Does this say the North American lichen species is an example meant to illustrate how slowly lichen grows?

    Negative. Similar to what we said for (C), the limitation isn't discussed until the third paragraph (P3, S5), so the North American lichen example can't be meant to explain that limitation.

  5. E
    to provide a sense Remaining source text redacted.
    Why choice E matches the stem

    (E) Does this say the North American lichen species is an example meant to illustrate how slowly lichen grows?

    Yes! The North American lichen is presented as an example of the slow but constant growth of lichen, and it provides information about the growth rate of one species. In stating that it grows "9.5 millimeters each century" (P2, S5), the passage establishes that it takes 100 years for it to grow very little — thus highlighting the long timescale on which it happens. This is, therefore, the correct answer.

What this tests

Question analytics

Based on historical answer selection rates for this question.

Answer choice distribution

  1. A 9%
  2. B 4%
  3. C 4%
  4. D 5%
  5. E Credited 78%

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