//4.b. Climate change is altering sea levels

Question 1

How are eustatic and isostatic sea level rise affecting sea levels

Answer 1

• the earth’s sea level has fluctuated over the geological past
• absolute changes in sea level are eustatic and changes in the absolute level of the land are isostatic
• eustatic sea level is taking place at an accelerating rate, averaging approximately 3.0mm per year at present

Question 2

What are the causes of sea level change

Answer 2

• thermal expansion of water- increase in surface water temperatures, sea water decreseases in density, volume increases and sea level rises
• melting of glaciers and ice caps due to increase in air temperatures
• melting of Greenland and Antarctic ice sheets- this is more complex as the central parts are thickening slightly but the edges are thinning rapidly

Question 3

Case study- the Maldives- physical geography+population threats and adaptations by government and communities

Answer 3

• threats- highest point 2.4m above sea level and population growth puts pressure on other factors
• adaptations- improve sea defences, promote migration of unskilled workers, construct artificial islands, raise key infrastucture higher

Question 4

Case study- the Maldives- fresh water threats and adaptations by government and communities

Answer 4

• threats- sea level threatens to contaminate aquifers with salt water
• adaptations- collect rainwater and promote groundwater more effectively

Question 5

Case study- the Maldives- economy threats and adaptations by government and communities

Answer 5

• threats- tourism numbers fall as some locations are lost to the sea
• adaptations- protect tourism industry

Question 6

Case study- the Maldives- employment threats and adaptations by government and communities

Answer 6

• threats- agricultural production threatened, as is tourism
• employment- provide job opportunitis e.g. land reclamation, jobs related to strategies dealing with increased sea levels

Question 7

Case study- the Maldives- industry threats and adaptations by government and communities

Answer 7

• threats- long term threats to fish stocks from ocean acidifcation and loss of coral reefs as nursery areas
• adaptations- protect coral reefs through marine reserve, more salt tolerant crops e.g. potatoes, carrots, sugar to protect resources