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Model answers to the 2018 A level exam:
03.1 - Outline the processes, which lead to the development of barrier beaches. (4)
A barrier beach is usually formed as an extension of a spit. The prevailing wind will control the
orientation of the approaching waves and if this is around a 45-degree angle to the coast, the swash
will move up and across the beach to allow longshore drift to develop a drift-aligned beach. Once
this process develops across a bay, a spit will be enlarged into a bar on the condition, that there is
not a strong river current to limit deposition. Once this has taken place an area of water will be left
inland of the bar (a lagoon) and in tropical climates this areas will be colonised by mangroves
03.2 Analyse the data shown in figure 5. (6)
This is a coastline which is being affected by longshore drift. The sediment cell is approximately 50-60
km long and the longshore current is moving sediment from east to west. The dominant wave
direction is north, north-west. It suggests that waves must be hitting the coastline at a slight angle
moving the sediment in a westerly direction. There appears to be no coastal protection in place and
significant quantities of material are being moved annually - 70,000 m3 from the eastern end of the
littoral cell. This suggests that erosion should be occurring at the eastern end as there is no apparent
sediment input from rivers or from further along the eastern edge of the coastline. The sediments
appear to be being moving in an anti-clockwise direction around the bay. There is a significant input
of sediment (240,000 m3) into the bay presumably as a result of river deposition. This continues to
be circulated around the bay in an anti-clockwise direction. The river itself may be causing erosion in
the bay. There is a zone of erosion at the point where the river meets the bay and just a little further
east there is a zone of deposition. Significant quantities of material appear to be lost to wind erosion
as the sediment is blown inland (35, 000 m3). This is occurring in the north-west of Chabahar Bay.
Overall the bay is experiencing significantly more deposition than erosion due the contribution of
longshore transported material and the input from the river.
03.3 Using Figure 6a, Figure 6b and your own knowledge, assess the potential impact of these
changes on coastal landform development in this area. (6)
Figure 6a shows relative sea levels 20,000 years ago during the height of the Devensian ice age. Since
this time orbital changes of the earth has increased levels of solar radiation which has led to the
melting of ice in the high latitudes (North of 55’N). This loss of continental ice will has added water to
the oceans and combined with the thermal expansion of water through warmer temperatures, the
sea would have led to Eustatic sea level rise. In areas such as Croatia (45’N 14’E) the concordant
coast would have been flooded leading to a series of valleys being submerged to leave parallel lines
of higher land left as islands to create a Dalmatian coastline. In Southern England (51’N 3’W)
dendritic river valleys would have been flooded to create Rias and in Norway (60’N 5’E) glacial
eroded valleys would have been flooded to form fjords.
At a slower pace of change, the landscape of Northern Europe would have experienced regional
change through isostatic rebound. The loss of weight of the high latitude ice cover would have
caused the coastline of Scotland to elevate and cause raise beaches to form as they are emerged
from the original coastline.
This study source was downloaded by 100000842568006 from CourseHero.com on 05-19-2022 14:12:48 GMT -05:00
https://www.coursehero.com/file/93731949/Coasts-2018docx/
Model answers to the 2018 A level exam:
03.1 - Outline the processes, which lead to the development of barrier beaches. (4)
A barrier beach is usually formed as an extension of a spit. The prevailing wind will control the
orientation of the approaching waves and if this is around a 45-degree angle to the coast, the swash
will move up and across the beach to allow longshore drift to develop a drift-aligned beach. Once
this process develops across a bay, a spit will be enlarged into a bar on the condition, that there is
not a strong river current to limit deposition. Once this has taken place an area of water will be left
inland of the bar (a lagoon) and in tropical climates this areas will be colonised by mangroves
03.2 Analyse the data shown in figure 5. (6)
This is a coastline which is being affected by longshore drift. The sediment cell is approximately 50-60
km long and the longshore current is moving sediment from east to west. The dominant wave
direction is north, north-west. It suggests that waves must be hitting the coastline at a slight angle
moving the sediment in a westerly direction. There appears to be no coastal protection in place and
significant quantities of material are being moved annually - 70,000 m3 from the eastern end of the
littoral cell. This suggests that erosion should be occurring at the eastern end as there is no apparent
sediment input from rivers or from further along the eastern edge of the coastline. The sediments
appear to be being moving in an anti-clockwise direction around the bay. There is a significant input
of sediment (240,000 m3) into the bay presumably as a result of river deposition. This continues to
be circulated around the bay in an anti-clockwise direction. The river itself may be causing erosion in
the bay. There is a zone of erosion at the point where the river meets the bay and just a little further
east there is a zone of deposition. Significant quantities of material appear to be lost to wind erosion
as the sediment is blown inland (35, 000 m3). This is occurring in the north-west of Chabahar Bay.
Overall the bay is experiencing significantly more deposition than erosion due the contribution of
longshore transported material and the input from the river.
03.3 Using Figure 6a, Figure 6b and your own knowledge, assess the potential impact of these
changes on coastal landform development in this area. (6)
Figure 6a shows relative sea levels 20,000 years ago during the height of the Devensian ice age. Since
this time orbital changes of the earth has increased levels of solar radiation which has led to the
melting of ice in the high latitudes (North of 55’N). This loss of continental ice will has added water to
the oceans and combined with the thermal expansion of water through warmer temperatures, the
sea would have led to Eustatic sea level rise. In areas such as Croatia (45’N 14’E) the concordant
coast would have been flooded leading to a series of valleys being submerged to leave parallel lines
of higher land left as islands to create a Dalmatian coastline. In Southern England (51’N 3’W)
dendritic river valleys would have been flooded to create Rias and in Norway (60’N 5’E) glacial
eroded valleys would have been flooded to form fjords.
At a slower pace of change, the landscape of Northern Europe would have experienced regional
change through isostatic rebound. The loss of weight of the high latitude ice cover would have
caused the coastline of Scotland to elevate and cause raise beaches to form as they are emerged
from the original coastline.
This study source was downloaded by 100000842568006 from CourseHero.com on 05-19-2022 14:12:48 GMT -05:00
https://www.coursehero.com/file/93731949/Coasts-2018docx/
