What are emergent coastlines caused by?
marine regression (fall in sea level)
What is a raised beach (emergent)
areas of former wave-cut platforms and their beaches left at a higher sea level due to marine regression.
Found at a distance inland
E.g. Isle of Arran
What are abandoned cliff lines (emergent)
relict cliffs with wave-cut notches, caves, and arches behind raised beaches
Formed by marine erosion when sea levels were higher
Sub-aerial process now dominate
What are fossil cliffs
near vertical sedimentary slopes
Formed by marine processes but are now inland
Sea caves, wave-cut platforms are visible
What caused raised beaches, abandoned clifflines and fossil cliffs?
Land rose due to isostatic rebound in Scotland
Global sea levels during the Devensian fell by up to 120m
Post-glacial rise was rapid and drowned many coastlines
As isostatic rebound is slow, erosion was able to create layers showing former sea levels
Scotland has evidence of 7 raised beaches
How are submergent coastlines formed?
isostatic fall
Marine transgression
South England is sinking by 1.1mm and with global sea level rise it goes up to 3.9 mm a year
What is a Ria? - Devon
Drowned river valley
Plan view = winding profile and reflects original route of the valley
Cross section = shallower water that deepens towards the centre +has exposed gently sloping valley sides
Long profile = Even and smooth and deepens at the mouth
Flooded drainage basin
What is a Fjord? - Milford Sound, New Zealand
flooded glaciated u-shaped valley
Plan view = straighter profile as glacier truncated interlocking spurs
Cross section = steep valley sides and over 1000m in depth
Long profile = shallower mouth - Sherries are form
How was the Dalmatian coast formed ?
African and Eurasian plate collided
Valleys (anticlines and synclines) lie parallel
When flooded the anticline remained visible and synclines are submerged