Note that a tsunami is a seismic sea wave. Note downed trees in the surf zone. Dune erosion on the Outer Banks of North Carolina near Cape Hatteras. Snow fences on the beach at Tybee Island, Georgia, used to slow wind and cause sand deposition from wind. Note the dune building that has occurred between the fences.
Vegetation stabilizes coastal dunes.
Signs ask visitors not to walk on the dunes to protect the vegetation. Barrier Islands Air view of Outer Banks of North Carolina near Kitty Hawk. Note fences meant to stabilize dunes on right. There is a rise and fall in sea level of approximately a meter or more, once or twice per day. The moon's gravitational pull.