Catastrophism is a related term of catastrophist.

As nouns the difference between catastrophism and catastrophist

is that catastrophism is (geology) the doctrine that sudden catastrophes, rather than continuous change, cause the main features of the earth's crust while catastrophist is a catastrophist person: a person who subscribes to a catastrophist theory.

As an adjective catastrophist is

of, having, or being a theory that explains a situation by positing one or more catastrophic events, as opposed to gradual changes.