The mayor of Alaska’s largest city submitted his resignation, four days after an anchorwoman at a local television station threatened to report he had posted nude photos of himself on a website. Ethan Berkowitz initially denied the allegation, but on Monday acknowledged he had an inappropriate relationship with Maria Athens, the anchor at a Fox/ABC combined station in Anchorage. “It is with profound sadness and humility that I resign as mayor of the Municipality of Anchorage,” he said in a statement read Tuesday night at the Anchorage Assembly meeting by his chief of staff, Jason Bockenstedt, and later emailed to the media.