What do the world's oldest icebergs look like

Icebergs that broke away from the mainland hundreds of years ago and still float in the ocean are one of the most beautiful creations of nature. Every year hundreds of thousands of icebergs break off from glaciers and slide into the sea near the North and South Poles. Only 10% of the total volume of the iceberg can be seen on the surface of the water, and everything else is hidden under water. Some of the icebergs formed from lumps of snow have been floating for more than 30 thousand years.

Glacier researcher Robert Gilmore, who visits Antarctica every year on expeditions for the Polar Latitudes organization, says: "They melt incredibly slowly. And they move slowly, a maximum of two knots, depending on the current. Icebergs vary greatly in appearance. Darker streaks on some of them may appear when ice water penetrates into the cavities and freezes again. Bluish icebergs are older and more compact, so they do not refract light and it turns out a kind of optical illusion."

Icebergs melt on a summer night in the glacier lagoon of Jekulsaurloon in Iceland, reflecting in the water under a cloudy sky.

This iceberg was captured by photographer Ralph Clevenger in Antarctica.

Storms sculpted a bizarre sculpture from this iceberg off the coast of Greenland.

A colony of penguins in a sea of Cattle has turned this ancient iceberg into an amusement park.

Perito Moreno Glacier in Argentina.

Photographer Alex Cornell captured this tilted iceberg off the coast of Antarctica. This effect is due to an internal imbalance in the iceberg.

Penguins on an iceberg in the Weddell Sea.

A flat-topped iceberg that is falling apart.

Large icebergs contain a lot of sediment and minerals brought by the wind, which look like layers when they roll over.

Iceberg off the coast of Isfjord, Ilulissat, Greenland.

A protruding iceberg and its impressive part, visible through clear cold water.

When the sun came out, a beautiful haze appeared off the shores of the Sermek-Kuyallek glacier, the most prolific iceberg in the Northern Hemisphere.

Iceberg on the surface of Yekulsaurloun.

Iceberg in the Inner Strait of Alaska.