Sea level changes have produced emergent and submergent coastlines

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