The vacating of streets in whole or in part by the voluntary action of a municipality, for the purpose of making it possible for the court to mitigate the hardships suffered by individuals because of the change in land boundaries caused by the act of God, consisting of an earthslide, can be accomplished by the offer of the municipality expressed in the complaint followed by the court's approval of it in the action authorized in AS 09.45.800 - 09.45.880, without other formalities. This provision is a special emergency substitute for the provisions contained in AS 29.40.120 - 29.40.160.