PT5.S1.Q12 - Impact craters caused by meteorites

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  taschasp Alum Member Sage ⭐

  December 2019 796 karma

  So the stimulus is saying these craters are all over the earth, but there are way more in "geographically stable regions." Then it concludes that there must be more meteors in those regions because they are stable (i.e. because of the "lower rates of destructive geophysical processes in those regions"). In other words, in the less stable regions, the meteorites broke down or disintegrated or something, so that's why we haven't found the craters. It's not that more meteors fell in certain areas; its that in certain areas, the remains of the craters perished more than others. So it's trying to say that the "stability" of those regions caused the preponderance of craters (or the instability of the other regions caused the absence of the craters).

  So, they're making an assumption there, about why they found more craters in certain places. Like, what if meteors had just been more likely to fall in those stable regions, for some other reason? So it could have been differences in how many meteors fell in different places, rather than a difference in how many of the craters remained visible over time.

  If D is true, then it precludes the other possibility that meteors could have fallen in different proportions. It's saying that meteors covered all parts of the earth fairly equally, so if there are more craters in some places than others, it must be because the craters were less likely to disappear over time in those places (a.k.a. because of "lower rates of destructive geophysical processes").

  Note that E actually sort of weakens the argument (by providing a third alternative, that we found more craters in stable regions because... well, we've just looked around there more!?), and B and C are just irrelevant--we don't really care about increasing rates of meteors striking the earth, or how quickly the craters perish. A doesn't help either, because if that were true, then we'd have a pretty even relationship between the rate of meteors falling in different places and how many craters are still left; it'd explain why some of the craters didn't last, but not provide any support to the idea that the reason they are more sparse in certain places is because those specific regions were more prone to disintegration.

  Hope this helps!
• 1 Like

  taschasp Alum Member Sage ⭐

  December 2019 796 karma

  Also, you want to format your post title like this: PT5.S1.Q12