cataclysm vs calamity

cataclysm and calamity both are nouns.

Word	Noun	Adjective	Verb	Adverb
cataclysm	Yes	No	No	No
calamity	Yes	No	No	No

As nouns, cataclysm and calamity are synonyms defined as:

Other synonyms of cataclysm include catastrophe, disaster, tragedy.

cataclysm (noun)	calamity (noun)
an event resulting in great loss and misfortune	an event resulting in great loss and misfortune
a sudden violent change in the earth's surface