1. Coastal Regions and Land Loss Chapter 10

2. Morris Island Lighthouse, SC

3. Coastlines Active vs. passive margins Population concentration Seven of 20 largest US cities on or near coastline 53% US population lives in coastal counties

4. Deep-water wave form (water depth > 0.5L)

7. Factors controlling waves 1. 1.Wind speed 2. 2.Duration 3. 3.Fetch

10. Plunging breakers

11. Spilling breakers

15. Coastal erosion along beach at Santa Barbara, CA

18. Longshore drift and transport

21. Sea level changes Eustatic sea level rise caused by Changes in amount of water in oceans   Short-term Changes in shapes and volumes of oceans   Very long term   Related to sea floor spreading Climate is major control Thermal expansion or contraction of water

22. Shoreline conditions Emergent Earthquakes and uplift/downdrop Glacial rebound Area: New England Submergent Higher sea level Irregular shorelines common Area: Mid-Atlantic area – Chesapeake Bay (VA)

24. Very short-term changes Storm surges Changing tides Extreme: Bay of Fundy, eastern Canada 15 m tidal range twice daily Normal daily changes (2 high, 2 low)

25. Coastal erosion rates

26. Note changes based on shoreline type low coastlines most affected

27. Minimizing coastal hazards Hard stabilization Seawalls: concrete, large blocks Cause more problems than they solve; they enhance beach erosion

28. n n Groins : built perpendicular to shoreline n n Problem is the area down drift from groin is not fully replenished n n Fix by beach nourishment

29. Chesil Beach on southern coast of England

30. Breakwaters Built to protect shoreline by intercepting waves Jetties Usually pairs of protrusions Note beach modifications

31. Soft (beach) Stabilization Moving sand around, usually from offshore Temporary solution due to dynamics Must be repeated

32. Managed “retreat” solution Prevent building Relocate threatened buildings

33. Miami Beach, FL 24 million cubic yards over 10 years Before beach nourishmentAfter beach nourishment

34. Cape Hatteras lighthouse Built 500 m from waterLater moved 850 m inland