There is no single, universally agreed upon system of classifying coastlines. Given the large number and variety of classification approaches, oceanographers often gravitate towards the method they consider to be most useful in studying coastal zone...
Like a sparkling ribbon pressed between land and ocean, the coast draws people to it the world over. In the United States, almost eighty percent of the population lives in coastal counties. Unfortunately, most human impact on coastlines is negative.
Exposure to varying amounts of geologic activity is one of the major reasons why each of the United States coastal zones is so distinct.