Band 7+: The graph below shows the maximum percentage of surface ice covering of the great lakes between 2000 and 2020. Summarize the information by selecting and reporting the main features, and make comparison where relevant.

This line graph illustrates the highest percentage of the lake surface covered by ice in three of the Great Lakes from 2000 to 2015.

There is a general trend of similar levels in Lake Superior and Lake Michigan, while Lake Erie followed a different pattern. However, all of the lakes show a sharp decline after 2015.

Firstly, in Lake Superior, there was a considerable variation in the ice coverage, starting at 40 percent, with a high of 95 percent and a low of 20 percent in 2020. Meanwhile, Lake Michigan has a lower percentage of covered ice each year, but the changes are consistent in both lakes. The high peaked around 80% in 2015 and the low fell to 20% in 2020. The greatest difference between the two lakes was in 2005, when Lake Superior had 50% coverage and Lake Michigan had approximately 30%.

By contrast, Lake Erie had a completely different trend, as the maximum amount of ice fluctuated between only 90% and 95% from 2000 to 2015. After that point, the percentage dropped dramatically to a mere 40% in 2020.