According to the generally accepted theory of plate tectonics, the earth's crust consists of a dozen or so plates of solid rock moving across the mantle—the slightly fluid layer of rock between crust and core. ████ ███████████ ███ ████ ██ █████████ ██ █ ██████ ██ ███ ████████ ██ █████ ██████ ███████ ███ ███████ ██ ████ ████████ ███
Phenomenon & hypothesis ·Earthquakes explained by plates colliding
Regions with little subduction (plate collision) could still cause earthquakes, depending on collision type (collision type 1 causes greater risk)
Passage Style
Phenomenon-hypothesis (RC)
Single position
23.
According to the passage, what ███████ ████ ███ ██████ ██████ ██ ███ ████ █████████ ████████
Question Type
Stated
The author tells us what happens in the middle of P2: “In contrast, the plate collisions in the quiet subduction zones occur between two plates that are moving in the same general direction—the second plate's motion is simply faster than that of the first, and its leading edge therefore becomes subducted. But in this type of subduction, the collision zone moves with a comparatively high velocity relative to the mantle below. Thus, rather like an oar dipped into the water from a moving boat, the overtaking plate encounters great resistance from the mantle and is forced to descend steeply as it is absorbed into the mantle. The steep descent of the overtaking plate in this type of collision reduces the amount of contact between the two plates, and the earthquake-producing friction is thereby reduced as well.”
The leading edge of the faster-moving plate is subducted under the trailing edge of the slower plate. So the trailing edge of the slower plate isn’t subducted under faster plate.
3%
b
The leading edge ██ ███ █████████████ █████ ██ █████████ █████ ███ █████████████ ██████
The leading edge of the faster-moving plate is subducted under the trailing edge of the slower plate. The leading edge of the slower-moving plate isn’t subducted under anything.
The leading edge of the faster-moving plate is subducted under the trailing edge. It’s not the trailing edge of the faster plate that’s subducted; it’s the leading edge of that plate.
6%
d
The leading edge ██ ███ █████████████ █████ ██ █████████ █████ ███ █████████████ ██████
Stated in the middle of P2: “In contrast, the plate collisions in the quiet subduction zones occur between two plates that are moving in the same general direction—the second plate's motion is simply faster than that of the first, and its leading edge therefore becomes subducted.”
81%
e
The leading edge ██ ███ ███████ █████ ██ █████████ █████ ███ ██████ ██████
The author doesn’t discuss smaller vs. larger plates. What matters is what’s faster-moving and slower-moving.
1%
Difficulty
82% of people who answer get this correct
This is a moderately difficult question.
It is somewhat easier than other questions in this passage.
CURVE
Score of students with a 50% chance of getting this right
25%140
148
75%155
Analysis
Stated
Stated
Stems asking us to identify an idea that appears explicitly in the passage (as opposed to ideas that are merely implied).
Passages that focus on describing or evaluating potential explanations for a given phenomenon. Causal reasoning features prominently in these passages.
