#26 - Concept Reference, Must Be True

[Administrator]

Please post your questions below!

[manchas]

Having labored over Q25 and eventually choosing the correct answer there, you'd think 26 would have been a lot easier for me, but I could not figure out whether 26 was asking about the accepted theory or the new proposal by the group of scientists.

So I went back and changed my answer from (C) to (A), justifying (A) with Lines 5-9: Most quakes can be explained...when..the plates collide, one is forced under the other...until it becomes one with the ..mantle.

Why are those lines not sufficient for (A)?

Is it because (A) is in fact paraphrasing 38-44 - times where you have the specific type of subduction that produces NO quakes (L 38-44)?

It was just really hard for me to distinguish which part of the passage (A) was referencing.


Thanks in advance

[Zach Foreman]

manchas,
For my first prepress, I went off of lines 11-13: Hot Zones or areas of high subduction. This would lead to answer choice D. However, I wanted, like you, to make sure that one of the other answer might be better, because of the newer theory.
The more nuanced theory says that there are regions of high subduction that are nonetheless quiet because the two plates are moving in the same direction and the subjected plate encounters greater resistance from the mantle and is absorbed into the mantle at a greater angle. We can use this to eliminate wrong answers. In fact, A, B and E are eliminated, leaving only C. We can now eliminate D because it doesn't account for the quiet areas of subduction whereas C does.
The sentence starting in line 41 eliminates A as a possible answer since a sharp descent reduces contact between plates which reduces earthquakes. I find it helpful in these science passages to make a table:

Quite subduction zone                                     Hot subduction zone
plates move in same direction                        plates move in opposite directions
subducted plate absorbed at steep angle       subducted plate absorbed at shallow angle
zone moving relative to mantle             zone motionless relative to mantle
lower friction between plates             higher friction between plates

[lsatmiracle]

hi had a quick question on this one. is B wrong just because it says "resistance from the mantle" when the resistance is coming from the other plate? i'm so dumb i didn't focus on all the words in the answer choice. thanks!

[lsatmiracle]

hi had a quick question on this one. is B wrong just because it says "resistance from the mantle" when the resistance is coming from the other plate? i'm so dumb i didn't focus on all the words in the answer choice. thanks!

wait sorry. B is wrong because where you get the most earthquakes are from when one plate's angle of descent is shallow and so there's great resistance between the two plates but these plates get little resistance from the mantle. is that correct?

[Rachael Wilkenfeld]

Exactly lsatmiracle. This passage was complex because you had to track different kinds of resistance (mantle v plates) and different reactions to subduction. Answer choice (B) is describing a great resistance from the mantle, which causes a steep decent and relatively low earthquake risk (see the first half of the second paragraph). Just as you note, answer choice (C) describes the shallow decent that has a high earthquake risk.

On this passage, I really took advantage of the scratch paper. I drew a little chart with earthquakes on one side, and low risk on the other. Not perfect, but it let me track the different characteristics in a visual, easy to read/reference sort of way. It's a different approach than I typically take in RC, but I found it helpful in this case because it was so easy to get the two categories confused.

Hope that helps!

[German.Steel]

This question really bothers me, because my understanding has always been that "according to" questions are the easiest and most straightforward in RC - simply find the precise line reference in the passage based on the question stem, and you're off to the races (like Lana Del Rey). But on this question, "which....kinds of regions experiences the most earthquakes?", I have an extremely precise reference from the passage that matches perfectly with the question stem: "Most earthquakes take place in....regions with very high levels of subduction." This, again, matches perfectly with D: "regions where there is the greatest amount of subduction."

Based on my understanding of how "according to" questions operate, that should be a slam dunk. So I can't help but wonder if I'm going about "according to" questions all wrong somehow. Am I?

I can consistently get -0 on LR and LG, but I feel like I've been treading water in the in the -1 to -3 range in RC, because of stuff like this. HELP!!!

[Robert Carroll]

German.Steel,

The prephrase is not quite accurate. In the middle of the first paragraph, we see that some places with high levels of subduction are nearly free of earthquakes. So it's not straightforwardly true that places with high levels of subduction have the most earthquakes - places with high levels of subduction also have few if any earthquakes. I think the issue here is a confusion between two very different statements:

1. "Most earthquakes occur in places with high levels of subduction."

vs

2. "Places with high levels of subduction have the most earthquakes."

The first is true and the second not necessarily true. 1 is true because, if we look at earthquakes, we'll find most of them in places with high levels of subduction. 2 isn't necessarily true because, if we choose a place with a high level of subduction, it may very well be a place with a high level of subduction that is nearly free of earthquakes. So there's no expectation that a majority of arears with high levels of subduction are places with high levels of earthquakes. If anything, the difference between the two statements is like the difference between two "most" statements that are in the opposite order.

Thus, answer choice (D) is a Shell Game wrong answer. It looks good, but it's not talking about the right class of things. Talking about earthquakes is good, but not about areas, because we don't know if most high-subduction areas are actually where we find the earthquakes (the high-subduction and earthquake-prone areas might be a small minority of all the high-subduction areas).

Robert Carroll

[German.Steel]

Ah. The "most" switch got me. I see exactly why (D) is wrong.

Thank you for correcting my stupidity!

[bjohnson2021]

Hello,

I am still having a hard time understanding why D is incorrect. I am basing my answer on "Most earthquakes take place in the earth’s seismic “hot zones”—regions with very high levels of subduction." (Idk how y'all find line numbers). I know that this doesn't account for the new theory, but it was the only attractive answer for me.

In regards to C, I thought that regions where subduction occurs at shallow angles leads to a more intense earthquake, not necessarily more earthquakes.