The Low and Ball of the Eastern Shore of Lake Michigan

Lows and balls constitute a series of submerged troughs and ridges built approximately parallel to beaches with an abundant supply of sand and a gently sloping bottom. They are the work of plunging breakers and form best where the shoreline is relatively straight and where the prevailing winds are onshore. They remain in approximately the same position as long as conditions do not change. If change in wave size (height or length) occurs, the lows and balls may move slightly onshore or offshore as the position of the breaker line changes. However, if the water-level lowers, or other conditions change so as to bring the crest of the ball near the surface, currents and waves of translation are set up across the top of the ball, and the structure then migrates shoreward as a subaqueous dune. The currents and waves of translation across the top of the ball prevent its being built up above the water surface by the work of the waves alone. Thus the ball is not the immediate forerunner of the offshore bar or barrier beach. On the inshore terrace, shoreward of the true lows and balls, ridges are built in various ways by waves and currents and frequently are driven to shore as subaqueous dunes. It is these minor ridges that have been mistaken by some investigators for migrating balls.