Crowds near the Mackinac Bridge in Michigan have gotten a rare glimpse at a beautiful phenomenon.
In Straits of Mackinac, which connects Lake Michigan and Lake Huron, huge chunks of blue ice have appeared, bringing photographers and visitors to the scene, as Cheryl Santa Maria reports for The Weather Network.
Blue ice has appeared before at the Great Lakes, but rarely to this extent, reports Meghan Bartels for Newsweek. The phenomenon is much more common on glaciers in Antarctica and the North Pole.
The ice itself is not actually blue.
George Leshkevich, physical scientist emeritus at National Oceanic and Atmospheric Administration’s Great Lakes Environmental Research Laboratory, explains to Michigan Radio’s Stateside that it just appears blue because of how light is reflected on it.
“People call it ‘blue ice,’” he says. “It [happens] because of three processes. One is that water absorbs other colors of the spectrum, the second is the lack of bubbles in the ice, the third is the ice thickness and density. And they’re all factors in what causes this phenomenon.”
Through the process of selective absorption, Leshkevich explains, the water absorbs blue wavelengths, and the density and lack of bubbles in the ice allows the wavelength to penetrate further. Light reflected from the ice then appears blue.
“It can occur probably anywhere on the Great Lakes,” he says. “You have to start out with fairly clean, clear water.”
As Bartels writes, it’s more common for ice to have more bubbles of air, reflecting all colors of light more evenly. This gives the ice cubes you'd find in your water glass a white appearance.
Local photographer Tori Burley tells Bartels this is the most blue she’s seen there. "Every year it comes up, but it doesn't crash into the shore the way it seems to have this year. When you think of ice, you think of ice on the ground, ice cubes—not bigger-than-your-car pieces of ice.”
Leshkevich explains to Stateside that ice can be moved around by the wind. That has allowed it to pile up and wash up on the shore.
The area recently experienced below freezing temperatures, allowing the blue ice to stick around longer.
Last minute decision last week Tuesday to drive up to the Mighty Mack to capture the "Blue Ice" phenomenon. Well worth the trip, very cool to see! As an aside, I was astounded by the sheer lack of common sense those visiting the Straits demonstrated, by walking unsafe distances from the shore onto the ice. Distances that none of the professional photographers that were up there shooting would even consider. Living & photographing on the shores of the Great Lakes, and bearing witness to daily news reports of water-related tragedies, I've developed a respect for the unrelenting power the Lakes yield. This is not the time of year to be "testing" the ice folks...please use caution out there! ©2018 Michigan Barefoot Memories Photography . . . . . . . . . . . #midwestisbest #puremichigan #greatlakesstate #ilovemichigan #mittigan #enjoymichigan #puremittigan #mi_playground #michiganawesome #michiganders #lakemichigan #greatlakes #mittenlove #igersmidwest #puremittenpride #michigrammers #thegreatlakestate #midwestmoment #funinmichigan #naturalmichigan #michiganwinter #nikon #mackinacbridge #mackinacisland #mackinaccity #straitsofmackinac #lakehuron #neverstopexploring @9and10news @upnorthlive @wxyzdetroit @usatodaytravel @accuweather @michiganradio @npr #cnnweather