1.3. How do coastal landforms evolve over time as climate changes?
3b. Submergent coastal landscapes form as sea level rises - How
landforms in submergent landscapes are influenced by rising sea
level due to a warming climate - Fjords Evidence of previous landforms:
Steep almost vertical cliffs indicating a former glacial U-
Sea level change: shaped valley, deep water due to depth of valley which could
be up to 1000’s m deep.
Fjords
1.4.submerged & formed when sea At end of valley floor - lower rates of glacial erosion as it’s
level rose and glaciers carved out huge seaward end where the ice was thinner – so fjord depth
U-shaped valleys becomes shallower at this point
Sea level rise floods the U-shaped
valleys. Modification during previous glacial/interglacial periods:
Most fjords are deeper than the coastal
During the glacial period, the glacier would have modified a
sea into which they empty (due to the
previous river valley - less of a winding feature (compared to
erosional power of the glaciers)
a ria) as the interlocking spurs would have been eroded
Climate: Fjords are usually deepest farther inland, where the glacial
Formed during Pleistocene glacial period (last glacial was 20,000 years ago) & was force was strongest (where the mass of glacier greatest)
then flooded during the Flandrian transgression (most recent warmer period – the Fjord floods during interglacial period as sea level rises
Holocene, when sea level rose)
Modification by present/future geomorphic processes:
Original landform feature: Marine processes are very active & further deepening of
fjords may occur due to huge depths of water
A U-shaped valley – created by the erosional energy of a glacier - moves very
Where glacial retreat is depositing glacial sediment, depth of
slowly down the valley but huge erosional potential, high rates of abrasion
fjords may be becoming shallower due to infill of these
sediments.
Sub-aerial weathering of valley sides may result in reduction
of steepness.
3b. Submergent coastal landscapes form as sea level rises - How
landforms in submergent landscapes are influenced by rising sea
level due to a warming climate - Fjords Evidence of previous landforms:
Steep almost vertical cliffs indicating a former glacial U-
Sea level change: shaped valley, deep water due to depth of valley which could
be up to 1000’s m deep.
Fjords
1.4.submerged & formed when sea At end of valley floor - lower rates of glacial erosion as it’s
level rose and glaciers carved out huge seaward end where the ice was thinner – so fjord depth
U-shaped valleys becomes shallower at this point
Sea level rise floods the U-shaped
valleys. Modification during previous glacial/interglacial periods:
Most fjords are deeper than the coastal
During the glacial period, the glacier would have modified a
sea into which they empty (due to the
previous river valley - less of a winding feature (compared to
erosional power of the glaciers)
a ria) as the interlocking spurs would have been eroded
Climate: Fjords are usually deepest farther inland, where the glacial
Formed during Pleistocene glacial period (last glacial was 20,000 years ago) & was force was strongest (where the mass of glacier greatest)
then flooded during the Flandrian transgression (most recent warmer period – the Fjord floods during interglacial period as sea level rises
Holocene, when sea level rose)
Modification by present/future geomorphic processes:
Original landform feature: Marine processes are very active & further deepening of
fjords may occur due to huge depths of water
A U-shaped valley – created by the erosional energy of a glacier - moves very
Where glacial retreat is depositing glacial sediment, depth of
slowly down the valley but huge erosional potential, high rates of abrasion
fjords may be becoming shallower due to infill of these
sediments.
Sub-aerial weathering of valley sides may result in reduction
of steepness.
