Use the paragraph to answer the question.

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.

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?

The analogy "they are called harmonic tremors, perhaps because of their constant release of energy, like one long song played underground" means that the constant release of energy from the little earthquakes (harmonic tremors) is similar to the continuous sound of a long song being played underground.

The analogy "they are called harmonic tremors, perhaps because of their constant release of energy, like one long song played underground" means that the constant release of energy from the small earthquakes happening below a volcano is compared to the continuous and rhythmic pattern of a song being played underground.

The analogy "they are called harmonic tremors, perhaps because of their constant release of energy, like one long song played underground" is used to describe the continuous and rhythmic nature of the small earthquakes that occur beneath a volcano. It compares the pattern of these tremors to a long song being played underground, suggesting the consistent release of energy that creates a harmonic or musical-like quality.