Types of Coasts

Coastal areas exist in a wide variety of shapes and forms. For this reason, scientists have found it useful to divide them into subgroups or types. One way of sorting coastlines is by when and how they were formed. 

All landforms, whether they are coasts or mountains, are formed and changed by geological processes. Coastlines can be divided into two large groups, based on whether their traits were primarily defined by land processes or by sea processes. Those sculpted by land processes are called primary coasts, and the ones that have been shaped by the ocean are called secondary coasts. 

The types of land processes that shape the appearance of a primary coast include precipitation (rain, snow, sleet, and hail), erosion, and deposition of sediments by wind and water. On a geologic time scale, primary coasts are fairly young and have been in very much the same condition since after the last ice age, 6,500 years ago. In this short stretch of geologic time, the ocean has not had time to alter them. 

The soil on a primary coast was once a part of the land. In some cases, the soil was deposited on the coast by wind or 

In the last ice age, when much of the water of the world s oceans was frozen as ice and sea levels were lower than they are now, the coasdines extended past their present positions. Then, as now, many rivers flowed to the sea, cutting deep, V-shaped valleys as they went. Thousands of years later, when much of the ice caps melted and sea levels rose, water filled in, or drowned, these river troughs. The type of coast that is dominated by an old river valley is called a drowned river, or ria coast (after the Spanish term ria, which means estuary ). The Chesapeake Bay is a good example of this type of coastline. 

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Abstract This chapter is devoted to a description of the present-day bottom topography and types of coasts of the Black Sea, as well as to the general character of the bottom sediments. Two maps of topography and sediments illustrate the morphology of the Black Sea basin and the particular features of the evolution of its coasts. 

Fig. 5 Coastal and bottom topography of the Aral Sea (according to [2, 24, 25]). Types of coasts (1) abrasion-denudation coasts (2) abrasion coasts with slumps (3) graded abrasion coasts (4) embayed coasts with accumulative landforms (5) graded complex coasts (6) embayed ingression coasts (7) graded accumulative coasts (8) deltaic coasts (9) reed coasts (10) nearshore shallow (0-20 m) (11) central depression (20 0 m) (12) central deep (40-68 m) (13) submarine ridge (ArkhangeTskii Ridge)...

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