microseism vs seism

microseism and seism both are nouns.

Word	Noun	Adjective	Verb	Adverb
microseism	Yes	No	No	No
seism	Yes	No	No	No

As nouns, seism is a hypernym of microseism; that is, seism is a word with a broader meaning than microseism:

microseism: a small earthquake
seism: shaking and vibration at the surface of the earth resulting from underground movement along a fault plane or from volcanic activity

Other hypernyms of microseism include earthquake, quake, temblor.

microseism (noun)	seism (noun)
a small earthquake	shaking and vibration at the surface of the earth resulting from underground movement along a fault plane or from volcanic activity