Which one of the following, if true, would present the greatest challenge to the new proposal relating the amount of ...

AndreaK on November 16, 2019

Hi @Meredith,

This is a tough passage, with plenty of unfamiliar vocabulary and natural processes (unless you’re a seismologist!). Let’s see if we can deconstruct these ideas.

We know from the scientists’ proposal discussed in the passage that the nature of the collisions from the tectonic plates could be what contributes to seismic activity, or lack thereof.

Let’s recapped what we learned about how this could be.

Plates moving in opposite directions (so going toward each other) = this is described in lines 24 to 29 as a “seismic hot zone” and lines 44 to 51 go on to further illustrate the effect of this type of collision, saying “larger plane of contact...like two sheets of sandpaper pressed together.”

Plates moving in the same direction = Line 29 all the way down to line 44 describes what happens in these circumstances. Line 29 that starts with “In contrast.....” and goes on to say plate collisions in quiet subduction zones are from plates moving in the same direction, which causes a different kind of subduction to take place that ultimately “reduces the amount of contact between the two plates, and the earthquake producing friction is thereby reduced as well.”

“Which one of the follow, if true, would present the greatest challenge to the new proposal relating the AMOUNT of seismic activity to the TYPE of collision between the tectonic plates?”

Let’s try predicting this answer choice based on what we read. If we’re going to challenge the proposed theory, we want something that’s going to show the opposite of (or something contradictory, or notably different from) what we were told. For instance, this could be high seismic activity in a subduction zone where the two plates are moving in the same direction, or low seismic activity where the plates are moving in opposite directions towards each other.

Correct Answer: C

C) There are areas where a plate has descended at a shallow angle during subduction (think sandpaper, plates moving in opposite directions toward each other) but where there have been few, if any, earthquakes (low seismic activity).

Bingo! This matches the second of our two predictions above perfectly.

As for the wrong answers, none of them get to the contradictory idea that we need to be able to challenge what’s being presented in the proposal.

A) “Some” is notoriously weak language, not ideal for a right answer in a lot of cases. Otherwise, this is actually in line with the proposal and supports the theory.

B) Doesn’t specify the nature of collision in order to be able to infer if there are contradictory circumstances here. If anything, this supports the theory because it’s describing the circumstances the theory sets out to explain with it’s “moving in the same direction = steep subduction, low friction and thus low seismic activity” theory.

D) Pulling together two disconnected ideas from the text that don’t create a contradictory process

E) In line with the proposal and supports the theory

Hope this helps!!