The place where two soil profiles meet i believe!
In physical geography<span>, a </span>dune<span> is a </span>hill<span> of loose </span>sand<span> built by </span>wind<span> or the flow of water.</span><span> Dunes occur in different shapes and sizes, formed by interaction with the flow of air or water. Most kinds of dunes are longer on the windward side where the sand is pushed up the dune and have a shorter "slip face" in the lee of the wind. The valley or trough between dunes is called a </span>slack<span>. A "dune field" is an area covered by extensive sand dunes. Dunes occur, for example, in some </span>deserts<span> and along some coasts.</span>
Tsunami has a very large WAVELENGTH and therefore, is more devastating.
1) This includes two leaf-feeding beetles, one root-boring weevil and one flower-feeding weevil. ... calmariensis are leaf-eating beetles which seriously affect growth and seed production by feeding on the leaves and new shoot growth of purple loosestrife plants.