- Created by: Lisa Paul
- Created on: 20-04-18 10:26
Landscapes of sea-level change
- Changes in sea level take place over time due to sea temperatures being colder or warmer than the present, or relative changes in land levels.
Eustatic change may result from a fall in sea level due to a new glacial period, when water is held as ice. This explains why during previous glacial periods the English Channel was dry land. At the end of a glacial period, the ice on land melts and global sea level rise again.
Isostatic change arises from changes in the relationship of land to sea. During a glacial period, as ice collects on the land, the extra weight presses down on the land causing it to sink and the sea level to rise. As the land ice melts the land begins to move back up to its original position (isostatic readjustment), and the sea level falls. This process is variable depending on the thickness of the original ice and the speed of its melting.
Tectonic processes associated with plate movement have also caused changes to sea level. By their nature they tend be quite localised.
In the last 10,000 years a geological period called the Holocene - and especially between 10,000- 6,000 years ago saw the global sea level rise very quickly.
It flooded the north sea and the English channel, broke the link between Britain and Ireland and flooded many river valleys to give the distinctive indented coastline of south west England and Ireland, known as rias. This rise in…