雪のけっしょうの旅

A Snowflake’s Tale

Snow is incredibly beautiful, but it’s also very important for the Earth’s environment. Every year, about one-third of the Earth’s land surface is covered in snow. Snow is the source of water and also affects the Earth’s temperature.

Snow first forms within clouds. When water vapor freezes around tiny dust particles in cold air, snowflakes are born. Snowflakes take many shapes—like plates or spikes—but all have hexagonal forms.

Once snow falls to the ground, it doesn’t stay in its original shape. Strong winds blow snow around, causing flakes to collide and lose their edges, becoming rounded. When wind gathers snow in one place, it forms large snowdrifts.

As snow accumulates, it creates a layered structure called a “snowpack.” New snow settles on top, while older snow lies beneath. Over time, temperature changes gradually alter the snow’s structure.

Occasionally, weak layers form within the snowpack. If heavy snow piles on top of these weak layers, avalanches can occur in mountains. Avalanches are extremely dangerous.

In very cold places, snow doesn’t melt for a long time. It gets pressed down little by little, becoming hard snow. After even more time passes, the snow turns into ice, forming large ice masses called glaciers.

In this way, snow falls from clouds to the ground, sometimes changing form into ice. Then, when the ice melts, it becomes water and returns to the sky.