Date | November 2016 | Marks available | 6 | Reference code | 16N.2.bp.3 |
Level | SL and HL | Paper | 2 | Time zone | |
Command term | Explain | Question number | 3 | Adapted from | N/A |
Question
The diagram shows four landforms (A, B, C, D) associated with a cliff.
(i) Identify two of the landforms shown in the diagram.
(ii) Outline how wave action could lead to the collapse of the cliff.
Explain three factors favouring the growth of coral reefs.
Examine the environmental and economic impacts of the pollution of oceans by oil.
Markscheme
(i) Any two of the following for [1]:
A cave
B stack
C arch
D wave-cut platform or shore-cut platform
[1 mark]
(ii) Award [1] for each valid point.
Possibilities include:
- eroded by hydraulic action/force of the wave
- abrasion/marine processes
- chemical processes, eg carbonation
- a notch is formed between low water mark and high water mark
- the notch is enlarged, the cliff becomes unstable and collapses.
Maximum [2] for an outline of processes that does not address the final point about notch and collapse.
[3 marks]
Award [1] for each reason and a further [1] for development/exemplification.
Possibilities include:
- sunlight is important for photosynthesis [1] – coral reefs contain algae (zooanthellae) which photsynthesize [1]
- salinity – coral not favoured by low salinity/freshwater [1] and is mainly in areas where the salinity is between 32 and 40 PSU (practical salinity units) – sudden decreases in salinity in oceans off major rivers may destroy coral [1]
- depth – coral is limited to about 100m [1] as below that it is too dark to photosynthesize effecitively [1]
- temperature – coral reefs grow most between 18–30°C [1] – most reef building coral cannot tolerate temperatures below 18°C and can only survive high temperatures for short periods [1]
- acidity of seawater [1] – increased acidity leads to less growth/decreases capacity of coral to build skeletons [1]
- pollution of oceans [1] – decreases water quality/less coral growth [1]
- management strategies [1], to protect reef/research/encourage growth [1].
[6 marks]
Environmental impacts might include: degraded ecosystems, flora and fauna mortality, reduced ecosystem productivity. The impacts may be concentrated in particular areas eg shipping lanes, offshore oil fields and nearby coasts.
Economic impacts might include: cost of clean-up, reduced fishery catches, unemployment, reduced tourism/recreational value, higher cost of oil (linked with possible restrictions on oil production or fines for companies, eg costs incurred by BP in relation to Gulf of Mexico).
Good answers may be carefully structured around an examination of different kinds of environmental and economic impacts. These may be local or global, short-term or long-term, small-scale or large-scale, intentional or unintentional. Impacts may also be experienced at a different place from the source of pollution due to tidal movements, and this may be examined. Good answers may also examine how impacts and cost may be spread across different user groups/stakeholders.
At band D, expect a description of some environmental and economic impacts of oil pollution.
At band E, expect either a more detailed and balanced explanation of the economic and environmental impacts of oil pollution or a structured attempt to examine some different aspects of the impacts (eg severity or spatial extent).
At band F, expect both.
Marks should be allocated according to the markbands.
[10 marks]