vulcanology vs geophysics

vulcanology and geophysics both are nouns.

Word	Noun	Adjective	Verb	Adverb
vulcanology	Yes	No	No	No
geophysics	Yes	No	No	No

As nouns, geophysics is a hypernym of vulcanology; that is, geophysics is a word with a broader meaning than vulcanology:

vulcanology: the branch of geology that studies volcanoes
geophysics: geology that uses physical principles to study properties of the earth

Other hypernyms of vulcanology include geophysical science.

vulcanology (noun)	geophysics (noun)
the branch of geology that studies volcanoes	geology that uses physical principles to study properties of the earth