There are a few possible ways to predict volcanic eruptions, some of these are as follows:
1) Volcanoes exhibit telltale signs of activity before an eruption. These include sudden changes in the color of the volcano’s lava, gas emissions, and the tilt or shape of the volcano.
2) Established monitoring programs can detect precursors to an eruption by analysing gases emitted by volcanoes. This can be used to give warning that an eruption may be imminent.