The Italian glacier turns pink due to melting algae

Pink snow has appeared on the Presena Glacier in northern Italy, researcher Biagio Di Mauro, of the Institute for Polar Sciences at the Italian National Research Council, said on Monday.

Although “watermelon snow” is, as is sometimes known, quite common in the Alps in spring and summer, this year it is more marked.

When Di Mauro went to the glacier on Saturday to explore, “there was a pretty impressive snow algae bloom,” he said.

He told CNN he believes an alga called Chlamydomonas nivalis is responsible for the color change.

This spring and summer, we saw low snowfall and high atmospheric temperatures, Di Mauro said, adding, “This creates the perfect environment for algae to grow.”

Di Mauro believes the snow turned pink due to the presence of algae.

Miguel Medina / AFP / Getty Images

Algae blooms are bad news for glacier health because darker snow absorbs more energy, which means it melts faster.

“It must be bad for the glacier,” Di Mauro said.

The phenomenon is particularly common this year, said Di Mauro, who plans to study it in more detail to determine algae concentration and map blooms using satellite data.

Di Mauro had previously studied the Morteratsch glacier in Switzerland, where an alga called Ancylonema nordenskioeldii turned the ice to purple.

This algae has also been found in southwestern Greenland, as well as in the Andes and the Himalayas.

Glaciers around the world are melting as a result of climate change.

In October 2019, it was discovered that glaciers in Switzerland had shrunk by 10% in the last five years, a rate never before recorded in more than a century of observation.

In Antarctica, the giant Denman Glacier has retreated nearly three miles in the last 22 years, according to research released in March.

If completely melted, sea levels will rise nearly five feet, the researchers said.