Question

What three factors do volcanologists monitor in order to determine whether magma is migrating toward the earth's surface?

Answer 1

1. Changes in the pattern of earthquakes produced by the movement of magma. 
2. Magma entering a near-surface magma chamber, which leads to inflation of the volcano.
3. Changes in the amount or composition of gases released from a volcano. 

Answer 2

Answer: Temperature, Pressure, and structural formation

Explanation:

Magma is a molten and semi-molten rock mixture found under the surface of the Earth. When magma breaks the surface, as a volcanic eruption, it is called lava. Volcanologist determine the movement of magma towards the earth surface by considering the temperature, pressure and structural formation of a place.