Which of the following is usually the first sign of impending eruption of a volcano?

Question

Quizplus · Accepted Answer

Small earthquakes are usually the first sign of impending eruption of a volcano. These earthquakes indicate the movement of magma beneath the surface, which can lead to an eruption. While the other options (increased hot spring activity, changes in gas emissions, changes in slope of the volcano, and changes in magnetic properties of the volcano) can also be signs of an impending eruption, they typically occur after or in conjunction with small earthquakes.

Which of the Following Is Usually the First Sign of Impending