natural action,
natural process,
activity,
action a process existing in or produced by nature (rather than by the intent of human beings); "the action of natural forces"; "volcanic activity"
fibrinolysis a normal ongoing process that dissolves fibrin and results in the removal of small blood clots; "drugs causing fibrinolysis have been utilized therapeutically"
disintegration -
total destruction; "bomb tests resulted in the annihilation of the atoll"