Date | November 2015 | Marks available | 6 | Reference code | 15N.2.sl.4 |
Level | SL only | Paper | 2 | Time zone | |
Command term | Explain | Question number | 4 | Adapted from | N/A |
Question
The photograph shows part of an advancing coast.
Describe two physical and/or human features shown in the photograph that suggest this is an advancing coastline.
Explain how oceanic trenches are formed.
“There are no simple solutions for the conflicts that arise over the use of coastal areas.” Discuss this statement.
Markscheme
In each case, award [1] for a brief statement of evidence (either a landform feature or reference to human activity), and [1] either for an extended description of the feature, or an explicit link that is made with the fact that the coast is advancing.
For example:
- the land here is very flat/sandy [1] suggesting it may be new land, a result of deposition by constructive waves [1]
- there is a new industrial/port area extending out from the coast [1], which is sited on land that appears to have been recently reclaimed from the sea [1]
- the main landform appears to be a spit [1]. There are a number of recurves (eg in square D3) located along the spit as a result of deposition over time [1]
- the growing marsh/salt marsh [1] is the result of freshwater from the stream mixing with salt water in an enclosed environment [1].
Award up to [2] for description and location of ocean trenches, and [4] for an explanation of their occurrence.
Description:
- very long, linear (underwater) features [1]
- the deepest parts of the oceans [1]
- may offer example(s) [1].
Explanation:
- formed at oceanic-continental subduction zones [1]
- denser oceanic crust plunges under less dense continental crust [1]
- alternatively, at an island arc system, denser ocean crust plunges under less dense ocean crust [1]
- as the plunging plate subducts into the mantle, it forms a steep, deep, trench, typically at an angle of 45° [1]
- the cause of plate movement is convection currents in the mantle, causing material to be pushed away from mid ocean ridges [1]
- provides relevant diagram [1].
Credit other valid points.
There are many competing land uses in coastal areas – urbanization, transport, tourism, recreation, fishing, industry, energy production, conservation. This can lead to many conflicts eg access to the land, use of resources, conflicts between farmers, developers, local residents etc.
Conflict can also arise over the use of coastal waters eg aquaculture, mangrove management, wind farms, etc.
For example, urbanization may lead to the loss of habitat/species diversity/lowering of groundwater, causing salt water intrusion/water pollution. This may anger those who are trying to conserve natural habitats and biodiversity.
Full marks can be achieved by a discussion of two conflicts and their possible solutions (do not expect balance).
Good answers may highlight the uneven power of different user groups (meaning that conflict is brushed aside rather than resolved). Another approach might be to establish interrelationships with processes such as in-migration, economic development or long-term sea-level changes: any of these processes may mean that conflicts over land use are especially hard to resolve.
If the candidate refers to geopolitical conflicts in relation to oceanic resources, rather than conflicts on a coastline, do not award above a band C.
At band D, expect an identification/description of at least one conflict (and interest groups) or description of some general solutions/strategies for coastal management.
At band E, expect either more detailed explanation of two conflicts and possible solutions, or some critical discussion of why conflicts are difficult to resolve.
At band F, expect both.
Marks should be allocated according to the markbands.