Answer:
This is a metaphor.
Step-by-step explanation:
"The volcanic eruption" shows that "his rage" is sudden and explosive. It's not like he got mad and literally erupted a volcano. Those things only happen in cliché movies. It's a figure of speech. It's not a simile(metaphors are commonly mistaken for them) because similes would have "like" or "as".
Hope this helps!