Like the swallows return to Capistrano – oh, wait, they don’t return there anymore. Like the buzzards return to Hinckley, Ohio, the ice balls have returned to Russia, this time in the Gulf of Finland off the country’s northwestern coast. Ice balls? Isn’t that what they call high school proms in Siberia?
Pictures of the mysterious ice balls began showing up on social media on December 10th. The balls are strangely uniform in size – about 7 inches (17 cm) in diameter … that’s slightly smaller than a volleyball and double the diameter of a softball. In other words, these are not the kind of ice balls you find floating in drinks at your fancier Christmas parties. Witnesses saw thousands of them bobbing in the frigid water against the shore. The scene was reminiscent of the appearance of the ice balls last year in the Gulf of Ob near a beach in western Siberia. That was reminiscent of the scene in 2015 when thousand of ice balls popped up in the Gulf of Finland, this time off the coast of Tallinn in Estonia. And all of those look like the ice balls that show up regularly on Lake Michigan in the US. What are they and why do they keep coming back to certain locales?
The “what” starts with slushy “slob” ice, which is that mushy not-quite-a-berg stuff that is ill-suited for skating. The next ingredient is wind, which blows the slob ice around. Ingredient number three is location – the slob ice needs to be blown around in very shallow waters so it rubs against the shore or sea bed and is rolled into balls much like the start of a typical snowman. Finally, the temperature needs to drop so the balls freeze. All that’s left is timing – the best time for them to show up is overnight so the locals think they’re the frozen eggs of whales, giant sturgeon or aliens.
That where this year’s ice balls become more mysterious. Beyond Russia reports that local ecologist Ilya Leukhin thinks the cause of these balls (pictures here) was not slob ice but an oil spill or industrial oil runoff.
“Salt water is a mix of a variety of salts, so it crystallizes unevenly under cold flows. Crystals are formed around the nucleus. And in this case, water has crystallized around a gas bubble or hydrophobic liquid, a drop of which has a round shape in water.”
An ice ball with a hydrophobic (water-repelling oil) center? Sounds like you shouldn’t pick one up and lick it.
As to why the ice balls keep returning mysteriously to the Gulf of Finland or Lake Michigan, the best guess is rare coincidences based on those spots having the right slob-ice/salinity/shallowness/temperature/wind combination.
Or if could be really cold aliens.