In 1868, Hayward was hit with a major earthquake that shook the East

Official Explanation for Q3:

the question looks for implication. The statements supporting answers (A) to (D) are: (A) "solid stone foundation will feel significantly less vibration than sand"; (B) "the Hayward Fault is... strike-slip... [which has) a repetitive pattern of occurrence"; (C) "today, most homes in the Bay Area are designed to withstand small-to-medium earthquakes due to earthquake retrofitting....The biggest changes... which made earthquakes riskier... buildings... include sky scrapers"; (D) "...the 1989 Loma Prieta quake, which was a 6.9 on the Richter scale... Today, most homes in the Bay Area... cannot hold against an 8.0 magnitude on the Richter scale." (E) is not implied, since the definition of the Richter scale does not relate to the destructive impact.

1. Which of the following titles best summarizes the contents of the passage?
a. Technology for Earthquake Strikes - Incorrect - Though the passage talks about technology to minimise the damage of earthquakes, it is not the main point
b. The Richter Scale: No Alert is Better - Incorrect - the passage does talk about ShakeAlert but it is not the main point
c. The 1868 Earthquake in Hayward Fault: Why It Matters Today - Correct
d. California Earthquakes: How to Measure Them - Incorrect
e. The Evolution of Earthquake Assessment - Incorrect

Answer C

2. Which of the following is true of the next Hayward Fault earthquake?
b. It should be expected any time soon. - Correct

The residents of California’s East Bay should note that the last five earthquakes on the Hayward Fault were each 140 years apart.

3. The author implies that ALL the following statements about earthquakes are true, EXCEPT:

a. A house built on sand would probably have more structural damage after a quake than a house built on granite. - Incorrect - Here we should know(assume) that granite is a solid stone?

The material of a home’s foundation, i.e. whether it is built on solid stone, dirt or sand, is an important determining factor in how much movement the structure experiences while the earth shakes. A solid stone foundation experiences significantly less vibration than does sand, which acts like water during a quake.

b. California residents living in major earthquake zones should be aware of past earthquakes because they tend to be cyclical. - Incorrect - it is mentioned
c. While buildings are now retrofitted for earthquakes, the risk of damage is higher nowadays because of skyscrapers. - Incorrect

d. Had the Loma Prieta quake happened today, most houses in California would have survived it.
Today, because of earthquake retrofitting, most homes in the Bay Area are designed to withstand small-to-medium earthquakes. ---> As per the bolded portion, we can infer that earthquake retrofitting was done in the Bay area. How can we infer that most houses in California will survive ?

The majority, however, cannot withstand a quake of 8.0 magnitude on the Richter scale. --> the 1989 Loma Prieta quake is well below the 8 magnitude

e. The magnitude of the quake determines the amount of damage, thus the Hayward quake of 1868 and the Loma Prieta quake had the same destructive impact. - The destructive impact depends on other factors too such as material of a home’s foundation , skyscrapers etc


4. The author mentions the homes’ foundations mainly to

a. give a baseline structural integrity measurement for the Richter scale. - Incorrect

b. understand the different possible impacts earthquakes can have on homes, based on their foundational materials. - I think different possible impact can also be interpreted as magnitude of the impact

c. show that the Richter scale does not alone determine the impact of quake damage. - The material of a home's foundation also affects the damage caused by a quake

The material of a home’s foundation, i.e. whether it is built on solid stone, dirt or sand, is an important determining factor in how much movement the structure experiences while the earth shakes. A solid stone foundation experiences significantly less vibration than does sand, which acts like water during a quake.

d. demonstrate the vulnerability of houses in earthquake zones. - Incorrect
e. give a demonstration of the impact of an 8.0 earthquake on different foundational surfaces. - Incorrect


In 4, I found it difficult to eliminate one after narrowing down to B and C.

5. The author implies ShakeAlert is flawed because it does NOT provide

a. long-term detection against quakes. - Correct
However, the ShakeAlert system notifies users only a few seconds in advance of an earthquake.


AjiteshArun , GMATNinja , MagooshExpert , DavidTutorexamPAL , other experts - please provide your advice for questions 3 and 4.

Hi,
For the 5th question option A ,what i interpreted from "long term detection" is does the shake alert is good for further usage after years for detecting the quakes..and since i know that last para states the "However, the ShakeAlert system notifies users only a few seconds in advance of an earthquake."....How to relate the "few seconds in advance" to "long term detection"

Please assist

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