1	Coastal Hazards
2	Coastlines
3	Types of Coastal Processes Divided into 3 categories: Water Level Changes Material Transport (including mass wasting) Water and Pollutants Are not uniformly distributed Stable vs. dynamic coastlines Can be short or long term
4	Natural Processes of Change Types of Processes: Waves Tides Storms Tsunamis Sea Level Change due to Land Subsidence & Uplift Sea Level Change due to Climate Change Net Effects: Flooding Landslides Sand Transport Sand and Rock Erosion Change is the size, shape or location of beaches
5	Mitigation: Coastal Erosion & Stabilization Three Approaches: 1. Hard structural stabilization Construction of groin, jetties, seawalls 2. Soft structural stabilization Beach renourishment 3. Non-structural stabilization Land-use restrictions, building guidelines
6	Mitigation: Water Quality & Pollution Problems Include: Estuary (e.g. Puget Sound) Health- Eutrophication Sewage / Industrial Contamination Saltwater Intrusion Sewage & Industrial outfalls into ocean Oil Spills
7	End Coastal Hazards lecture
8	Waves & Tides Constantly reform coastlines Higher energy = more erosion & transportation of the shore Waves Caused by wind Primary agent for eroding solid rock Storms intensify waves Tides Caused by gravitational pull of Sun & Moon High & Low Tides Water level changes 2x/day Longshore Current Causes littoral drift
9	Storms & Tsunamis Storms increase erosion & transportation potential by: Wave action Storm Surge-- Geohazard!!! Greater headward erosion Tsunamis- caused by submarine earthquake, volcanic activity, landslide, meteorite impact Can be ‘far-field’ or ‘local’ Cause intense erosion & redeposition of beach Geohazard!
10	Communities at Risk: Storm Surge Commonly associated with tropical cyclones Poses one of largest threats Can do more damage than hurricane winds Can be more deadly Hurricanes- batter Gulf & Atlantic Coast i.e. Katrina Typhoons- Pacific Ocean Effects of Storm Surge Raise water level temporarily Erosion of beach Destruction of non-engineered building (wave action) Destruction of engineered buildings (undercutting) Salt water in bays & estuaries
11	Communities at Risk: Tsunami Do you live in the Ring of Fire? Then you are at risk from tsunamis! Pacific Northwest & Northern CA 28 since 1812 Significant: 1700, 1964 Alaska 16 since 1863 Significant: 1958, 1964 Hawaii 32 since 1811. Significant: 1868, 1946, 1960, 1964, 1975 Gulf Coast, Altlantic Coast Low risk
12	Elevation of Tectonic Plates Subsidence of plate vs. uplift of plate Isostacy Create long-term changes in sea level Transgression Creates submergent coastlines Regression Creates emergent coastlines Deposition of sediments reflect change in sea level over geologic time
13	Climate Change & Sea Level Climate change affects sea level Global warming- seas rise / transgress Create submergent coastlines Our current climate scenario =1 foot rise per 100 years Projected shoreline retreat in CA = ~210- 430 ft in100 years! Projected shoreline retreat in FL = ~985 ft in 100 years! Global cooling- seas lower/regress Create emergent coastlines Pleistocene Sea Levels- reached over 300 feet lower than they are today! Wave cut terraces show paleo sea level