Here's Why Nantucket's "Frozen Waves" Are So Spectacular


Did Frozen's Elsa move to Massachusetts? Based on the photos, she would like the weather these days.

The snapshots, taken by photographer Jonathan Nimerfroh, capture the rare sight of frozen ocean waves.

The concept of a "frozen wave" may seem paradoxical, but they are the result of specific environmental factors, including the temperature of the air and water and the pattern of movement in the water. While fresh water freezes at 32 degrees Fahrenheit, sea water, due to its salt content, freezes at 28.4 degrees Fahrenheit.

Sea ice covers 15% of the earth's water at some point in the year, according to the National Oceanic and Atmospheric Administration. So when this happens, like when it did recently in Nantucket, loose needle-like ice crystals called frazil begin to form. As that happens, salt, which doesn't freeze, gets left behind. So, in addition to looking like a frozen wave, after a while the ice that forms actually becomes drinkable.

Aside from the temperature, the motion of the ocean matters for how the frozen waves appear, according to the National Snow and Ice Data Center. If the Nantucket shoreline was calm, then the ice that formed on top would have been smooth and dark at first, getting whiter as it thickened. But because the water was in perpetual motion, the frazil ice formed little ice patches that bump into each other and give rise to the slushy appearance. Eventually, if the temperature remains low long enough, the patches fuse to form a sheet.

Sea ice is more commonly found in polar oceans like the ones that surround the Arctic and Antarctica, where it helps to regulate the earth's climate. The National Snow and Ice Data center reports that "sea ice covers 25 million square kilometers of the planet's surface, or two and a half times the area of Canada."

While the frozen waves grace the shorelines of Nantucket, where the temperatures will inevitably increase as the seasons change (unless the ice queen really is in town), luckily we have photographers like Nimerfroh willing to brave the cold and deliver us such icy treats.