Continental margins on the east and west coasts of north america reflect the different tectonic settings, also reflected in land topography. West coast shoreline is typified by rocky cliffs due to active tectonic processes, which result in deformation and uplift. East coast shoreline is gently sloped, reflecting long-lived erosion and deposition at a tectonically quiet continental margin. Over time, the effect of waves and currents is to "iron out" irregularity in the coastline. When the sun and moon are horizontal with the earth. When the sun and moon are at a right angle to the earth. Every day, wind waves concentrate energy from the entire area of the water body and focus it along coastlines. Depending on conditions, wave energy can either erode or deposit sediments. Wave height h increases: wave steepens and eventually "breaks" How a beach gets constructed by "surf" from far away wind storms. In surf zone, swash is usually more energetic than backwash.