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317; Lecture 21
Term | Definition |
---|---|
Coastal geomorphology | the study of the morphological development and evolution of the coast as it acts under the influence of winds, waves, currents, and sea-level changes |
Surface waves | undulations formed by wind blowing over a water surface |
Fetch | the distance that the wind has blown over an area of sea |
Longshore currents | currents that move parallel to shore between the breaker zone and the shore |
Breaker zone | The zone within which waves approaching the coastline are breaking; a subsection of the shoreface |
Longshore drift | transport of sediments along shorelines by longshore currents |
Rip currents | relatively strong, narrow current flowing outward from the beach towards the ocean |
Tsunami | wave produced by faulting on the sea floor – pushing up of water by sudden change in depth |
Tides | movement of water bodies controlled by the gravitational interaction between the earth and moon |
Semi-diurnal tides | two high tides and two low tides per day |
Spring tides | higher than normal high tides occurring when the moon and sun are in line |
Neap tides | lower than normal low tides occurring when the moon and sun are at a 90° angle |
Microtidal | less than 2 m between high and low tide |
Mesotidal | 2-4 m between high and low tide |
Macrotidal | more than 4 m between high and low tide |
Wave-dominated coasts | longshore currents redistribute shoreline sediment |
Tide-dominated coasts | strong tidal currents redistribute shoreline sediment |