| Date | November 2015 | Marks available | 2 | Reference code | 15N.1.SL.TZ0.6 |
| Level | Standard Level | Paper | Paper 1 | Time zone | Time zone 0 |
| Command term | Calculate | Question number | 6 | Adapted from | N/A |
Question
Figure 4(a): Changes in Arctic sea ice in a typical year.
Figure 4(a)
[Source: Images courtesy of the National Snow and Ice Data Center, University of Colorado, Boulder]
Figure 4(b): Arctic sea ice extent.
Figure 4(b)
[Source: National Snow and Ice Data Center. Arctic Sea Ice News & Analysis / Charctic Interactive Sea Ice Graph. http://nsidc.
org/arcticseaicenews/charctic-interactive-sea-ice-graph/. Accessed November 18, 2015.]
Figure 4(c): Arctic sea ice extent 1979–2012.
[Source: Data source: http://nsidc.org]
Identify one factor that may be causing long-term changes in sea ice cover.
Calculate the percentage change in sea ice cover from March 1979 to March 2012 and from September 1979 to September 2012 in Figure 4(c).
Describe the trend seen in the sea ice cover data in Figure 4(b).
Markscheme
climate change/global warming;
Milankovitch cycles;
solar cycle/sunspot activity;
shifting ocean currents;
El Niño;
[1 max]
March: reduction (accept 8 %);
September: reduction;
[2]
slight reduction in March/remains steady since 1979;
greater reduction in September/downward trend;
[2]
Examiners report
Most candidates correctly answered this question.
A large number of candidates correctly answered this question. A common mistake was errors in the calculation of percentage change
This question was answered well by most candidates.
