explain the current and past sea level rise
- 1901-2018 average 15-25cm, 1.3 mm/year to 2.1 mm/year
- 1993-2017: rise of 7.5 cm, 3mm/year
- Resulting in accerlerating sea level rise
What is Sea Level?
Sea Level: measure of the average height of the surface of the sea; sea level is not uniform
What is Global (Eustatic) Sea Level?
average height of the ocean around the world
What is local sea level?
height of the water measured along the coast relative to specific point on land
What is mean sea level (tidal datum)?
average of hourly water level heights observed over 19 years
What are the causes for “Global Sea Level Change (Eustatic)”?
- Add or remove water
- Change water temperature
What controls regional sea level change?
- Change in land elevation
- Changes in gravitational forces
- Change in ocean circulation
What are the Coastal Hazards from sea level change
- Coastal flooding
- Exacerbates storm impacts
- Accelerates coastal erosion
Explain issues of “Coastal flooding” from sea level change
- Contamination of freshwater aquifers
- saltwater intrusion
- Sealevel rise and overdrawing can contaminate well water
explain affect of flooding of saltwater marshes, wetlands, estuaries?
- Acts as nature’s defence system
- reduces coastal energy, decrease wave size and speed, mitigates storm damage and protection against coastal erosion
hwo does coastal erosion occur faster?
acceleration due to wave action at higher elevations
