Flat shadows blanket the beach in Finland.

Residents of Oulu and brave tourists brave the biting cold to witness firsthand the thousands of perfectly round, pearl-like "eggs" that cover the beach on Hailuoto Island, in northern Ostrobothnia, Finland.

The phenomenon of egg-shaped ice formations appearing on beaches off the coast of Finland is caused by the seawater near the shore breaking up the soft ice. Melting snow sticks together and accumulates in the supercooled water, then the waves cause the ice to spin around, forming smooth balls. They are stacked on top of each other on Marigateemi beach like a "collection" of egg-shaped ice spheres.

Jouni Vainio, an ice expert at the Finnish Meteorological Institute, said the phenomenon is uncommon but can occur once a year under suitable weather conditions. Specifically, it happens when air and water temperatures are close to freezing point on a sloping sandy beach with calm (or gentle) waves. Snow crystals in the water move and clump together to form a soft, round ice core. The ice core then continues to move along the beach, freezing and growing larger.

According to Dr. James Carter, professor emeritus of geography and geology at Illinois State University (USA), this is the perfect time to witness this special phenomenon because ice is beginning to form on the water's surface, creating soft patches that move in the ocean waves.

Photos of egg-shaped ice bridges posted on Finnish social media and news outlets immediately attracted attention. People were impressed and curious about how these ice eggs were formed.

Hailuoto Island is located off the coast of Oulu in the Gulf of Twonia, separating Finland and Denmark in the far north of the Baltic Sea. Hailuoto is Finland's fourth largest city, covering an area of ​​200.53 km², and was formed approximately 2,000 years ago. The large island is famous for its traditional red farmhouses, wooden windmills, tall pine trees growing from the sandy soil, and beautiful beaches.

My Tong