for you folks who dont know what a pressure ridge is. this is a ridge in the ice caused by the ice expanding and freezing some a worse then others and they do creep daily,like a dam in the winter these are good places to avoid if possible,this one was 40 ft off shore and had to be delt with ,scores of vechicles traveled over the entrance area including myself, its always a bit scary driving on ice as it settle cracks as you drive even if theres 3 ft of ice, there was only 15" this year. this all happend friday night.