– zones of transition between the ocean and land, where waves, currents, and tides act to mold the landforms, which in turn influence the movement of the water.
– width of coasts: less than 1 km on cliffed coasts or more than 100 km in large estuaries (Delaware Bay)
 

Coastal Research

Scientists: only recently have undertaken comprehensive investigations of the coast; first systematic studies of coasts were conducted by geomorphologists in the early 20th century
- how coasts evolved
- processes

Engineers: construct harbors, docks, and bridges; stabilize and protect the open coasts
- most to prevent or at least slow erosion (e.g. Holland and Germany – protect and reclamate by dikes)

Before WW II, understand and control coasts; during the war, interest in coastal geomorphology and coastal processes – including waves, tides, currents, and wx patterns along coasts; much of the coasts throughout the world was mapped in detail.

After WW II, shift emphasis to engineering and global study of river deltas (Mississippi); broadened the research to beaches, inlets, and deltas of the of the world’s coasts – all potential settings for military activity

Modern Era of Coastal Research: 1960’s and 1970’s – primarily university researchers studied open coastal environments
 

East Coast – West Coast Comparison

East Coast...
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- wide coastal zones stretch to the sea, marked by wide beaches and high dunes, deltas, and barrier islands

Pacific Coast…
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- bedrock headlands interrupted by pocket beaches
 

Sediment

dissolved, suspended, bed
- process of erosion and deposition create landforms of great variety

- Pacific Coast – where erosion is dominate
- Atlantic Coast – where deposition is dominate
 

Coastal Processes

work in a short time and long time…   years or days (e.g. winter storms, swift tidal currents, etc.); can observe the geological development in only a few years; but the overall development of the coastal areas took as much as 180 M years to develop (period since the breakup of the continents)

Examples:

- Days/Years: action of waves, currents, and tides
- T years: gradual sea level changes (global climate changes) – falling for 1000’s years then rising for 1000’s years; now rising about 1-2 mm per year – result in long and slow, but steady, change.
- M years: mountain formation and erosion

Text shows the combination of short-term and long-term processes producing the deltas, estuaries, and barrier islands created by deposition and the rocky coastlines formed by erosion