The word "volcanic" is often used to describe something that is explosive, powerful, or intense. There are several synonyms that can be used in place of "volcanic" to add variety and interest to your writing. Some options include "fiery," "explosive," "eruptive," "seething," "incendiary," and "blazing." Each of these words provides a slightly different shade of meaning, allowing you to choose the word that best fits the context of your writing. For example, if you want to describe strong emotions, you might use "seething," while if you want to emphasize the visual aspect of a powerful event, "blazing" might be a better choice.