subsidence vs subsiding

subsidence and subsiding both are nouns.

Word	Noun	Adjective	Verb	Adverb
subsidence	Yes	No	No	No
subsiding	Yes	No	No	No

As nouns, subsidence and subsiding are synonyms defined as:

Other synonyms of subsidence include settling.

subsidence (noun)	subsiding (noun)
a gradual sinking to a lower level	a gradual sinking to a lower level
the sudden collapse of something into a hollow beneath it
an abatement in intensity or degree (as in the manifestations of a disease)