Sea Level Change

Question 1

explain the current and past sea level rise

Answer 1

• 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

Question 2

What is Sea Level?

Answer 2

Sea Level: measure of the average height of the surface of the sea; sea level is not uniform

Question 3

What is Global (Eustatic) Sea Level?

Answer 3

average height of the ocean around the world

Question 4

What is local sea level?

Answer 4

height of the water measured along the coast relative to specific point on land

Question 5

What is mean sea level (tidal datum)?

Answer 5

average of hourly water level heights observed over 19 years

Question 6

What are the causes for “Global Sea Level Change (Eustatic)”?

Answer 6

• Add or remove water
• Change water temperature

Question 7

What controls regional sea level change?

Answer 7

• Change in land elevation
• Changes in gravitational forces
• Change in ocean circulation

Question 8

What are the Coastal Hazards from sea level change

Answer 8

• Coastal flooding
• Exacerbates storm impacts
• Accelerates coastal erosion

Question 9

Explain issues of “Coastal flooding” from sea level change

Answer 9

• Contamination of freshwater aquifers
• saltwater intrusion
• Sealevel rise and overdrawing can contaminate well water

Question 10

explain affect of flooding of saltwater marshes, wetlands, estuaries?

Answer 10

• Acts as nature’s defence system
• reduces coastal energy, decrease wave size and speed, mitigates storm damage and protection against coastal erosion

Question 11

hwo does coastal erosion occur faster?

Answer 11

acceleration due to wave action at higher elevations