This is a very good image of strudel and rib and trough structures in a lake. In this image, the strudel are developed in fine-grained organic sediments in water depths of >3m and the rib and trough structures are developed on bouldery till in water depths of less than 3m. The original photo was taken at an altitude of 200-300m. See images 0047 and 0120 for more complete explanations of the genesis of these features.