Have you ever seen a black iceberg? A photo of an oddly colored chunk of ice went viral this week after it was posted to Reddit.
According to the Canadian Encyclopedia, a black iceberg isn’t rare but it is also rarely seen.
Several icebergs are colored black (or even green or brown) but the color typically lies below the surface of the water. The black iceberg in the viral photo is most likely the bottom of an iceberg that has rolled over.
The encyclopedia explains:
These (colored) icebergs have usually rolled over, exposing basal ice, or have emerged from below water level. The various colorations are caused by differences in density, air-bubble content and impurities. For example, black ice is of high density and bubble free; dark layers indicate the presence of rock materials derived from the base of the parent glacier. Occasionally, rocks may be found on the original upper surface of the iceberg. As the iceberg melts, these materials precipitate into marine or lake sediments.
Here’s a viral photo of the black iceberg.