Grist: On Earth, cycles are the norm. Tides, carbon, water, life - they ebb and flow. Change, by itself, isn`t necessarily strange. What is strange is when cycles are broken.
In other words, it`s not strange on its own that the level of the Great Lakes is dropping. It is strange that, when the lakes` levels normally change over a 13 year cycle, they`ve now been going down for 16 years straight. That`s 10 more than they should have been dropping for.
LiveScience:
Water levels have been declining...