SH,
I'm really a newby Pole watcher (2nd year) so I don't know what normal is. And I know stress fractures in ice only from skating (i'm Dutch): your skate-blade fits in one. The fracture in the middle of the image is 80-100km kilometers long, and more than a kilometer wide. It triggered my interest, because I thought that the thick multi year ice would sort of remain a solid mass, but apparently not, learning something new every day.