Sea level change Flashcards
What is sea level change due to? (Sea coasts)
Either eustatic or isostatic change
What is eustatic change? (Sea coasts)
The rise and fall in sea level
What are the characteristics of eustatic change? (Sea coasts)
- Effects are always global
- Decrease temperature means more precipitation falls as snow
- This increases the volume of water stored in glaciers, reducing volume of water in the sea
- Increased temperature melts the ice sheets
What is isostatic change? (Sea coasts)
The land rising relative to the sea level rise. Any downward movement of the land causes the sea level to rise
What are the characteristics of isostatic change? (Sea coasts)
- Effects are always local
- Caused by vertical movements in the land
- Subsidence of land due to shrinkage from draining marshland can lead to isostatic change
What are the impacts of sea level change? (Sea coasts)
- frequent coastal flooding
- low lying islands
- changes in coastline
What is the impact of more frequent coastal flooding, with examples? (Sea coasts)
Flooding of low lying land has increased due to sea level rise
e.g St Marks square, Venice has flooded 100 times since 1996
What is the impact of low lying islands, with examples? (Sea coasts)
They have disappeared completely due to sea level rise
e.g Maldives, if there is a 0.5m rise they will disappear
What is the impact of changes to the coastline, with examples? (Sea coasts)
Coastline changes and islands are created. The area of land decreases
e.g Britian’s separation from mainland Europe
What are the features of a coastline of submergence? (Sea coasts)
RIA’s
Fjords
Dalmatian coastline
What are RIA’s? (Sea coasts)
- Formed when river valleys have been partially submerged
- Long and cross profile
- Wide/deep at the mouth and become narrow/shallow further inland
What are fjords? (Sea coasts)
- Drowned glacier valleys
- Straight and narrow
- Steep sides
- Shallow mouth and deeper inland
What are dalmatian coastlines? (Sea coasts)
- Areas where valleys lie parallel to the coast
- Form from increase in sea level
- Valleys flood, leaving islands
What are the features of an emergence coastline? (Sea coasts)
- Raised beaches
- Abandoned coastline
- Slope over wall cliff
What are raised beaches? (Sea coasts)
- Formed when fall in sea level exposes wave cut platforms
- Over time beech sediment becomes vegetated
- Develops into soil
