Why does Lake Michigan look deep blue?

From the Earth Observatory at NASA: “The brilliant streaks of blue and green that color the Great Lakes in this image are a contradiction. read more

“The brilliant streaks of blue and green that color the Great Lakes in this image are a contradiction. The blue in Lake Michigan and Lake Huron is sediment brought to the surface when strong winds churned the lakes. The green in Lake Erie and in Lake Huron’s Saginaw Bay is algae, which builds on the surface when winds are calm. read more

Throughout the last few decades, the water quality in Lake Michigan has been very poor. However, several short-term and long-term factors are now contributing to the increasing clarity of its water. First, the recent introduction of zebra muscles (Study: Invasive zebra mussels improve water clarity in Great Lakes) has increased water clarity substantially. read more

Any large body of water will appear blue (or grey) because it picks up the color of the sky due to refraction, the bending of light as it encounters a medium different than the medium through which it has been traveling. read more

The phenomenon is common on glaciers, but not so much on large swathes of lake ice. It's happening where Lake Michigan meets Lake Huron, at a place called the Straits of Mackinac. There, fat slabs and mounds of cracked blue ice have collected near the shorelines. read more