You may not think earthquakes and volcanoes can go together, but they are unlikely friends, creating sensations under the earth’s surface. Most earthquakes occur because of the movement of tectonic plates previously described. Sometimes earthquakes happen below a volcano. This happens because magma, which is hot molten rock beneath the earth’s surface, pushes on rock until it breaks the rock and seeps into it. Then, the magma builds more pressure until it leaks more magma into the crack. Little earthquakes happen each time the rock breaks and lets in more magma. These little earthquakes are too small to feel. They are called harmonic tremors, perhaps because of their constant release of energy, like one long song played underground.

Question

What does the analogy "they are called harmonic tremors, perhaps because of their constant release of energy, like one long song played underground" from the paragraph mean?
1. Much like background music, little earthquakes tremor underground without much notice.
2. The tremors from small earthquakes follow unpredictable patterns, unlike musical meter.
3. The same amount of energy is released by music and small earthquakes.
4. When little earthquakes occur, they make sounds similar to music.

Answer 1

The correct interpretation of the analogy is:

1. Much like background music, little earthquakes tremor underground without much notice.

This choice captures the idea that harmonic tremors happen continuously and subtly beneath the surface, similar to how background music may be present without being the focal point of attention.