How do wave-dominated coasts differ from tide-dominated coasts?

The primary difference between wave-dominated and tide-dominated coasts lies in the dominant energy source shaping their morphology. Waves exert energy parallel to the coast, while tides exert influence perpendicular to it through flooding and ebbing cycles.1

Wave-Dominated Coasts

These coasts are characterized by extensive longshore transport and well-developed sand beaches, typically found on long, low-elevation barrier islands with few, widely spaced tidal inlets. Because these inlets are often small and unstable, they frequently require jetties to remain open for navigation.1

Tide-Dominated Coasts

These environments develop where tidal ranges are high or wave energy is low. Their morphology is defined by funnel-shaped embayments and long sediment bodies oriented perpendicular to the coastal trend. They feature extensive tidal flats, salt marshes, and tidal creeks.1

While some coasts exhibit a balance of both processes—known as mixed coasts—the distinction remains a fundamental way for geologists to classify coastal landforms based on how sediment is moved and deposited.1