This is an extention of a real experience, along the Gulf Coast of Texas, exploring a beach on Padre Island, south of Corpus Christi, putting my ear on the crest of the berm, I could hear and see grains of sand whoosh up by the landward drafts of wind, past my eye over the berm and land on the leeward side of the dune, to click and slip 2 or 3 millimeters down the slip face of the bay side of the berm. This happened a million times that afternoon. Imagine the accumulation over a million afternoons.