seismic vs seismal

seismic and seismal both are adjectives.

Word	Noun	Adjective	Verb	Adverb
seismic	No	Yes	No	No
seismal	No	Yes	No	No

As adjectives, seismic and seismal are synonyms defined as:

seismic and seismal: subject to or caused by an earthquake or earth vibration

seismic (adjective)	seismal (adjective)
subject to or caused by an earthquake or earth vibration	subject to or caused by an earthquake or earth vibration