Quirks & Quarks

What's feeding the algae growing on — and helping to melt — Greenland's ice?

Mineral dust linked to Greenland ice melt could be into driving multiple feedback loops that are accelerating ice loss.

Mineral dust linked to Greenland ice melt could be driving into multiple feedback loops

Assistant professor Jenine McCutcheon from the University of Waterloo, who was studying the algae on the Greenland Ice Sheet, discovered the algae that are darkening the ice sheet feed upon mineral dust from Greenland. (Jim McQuaid)

Greenland is living up to its name — and that's a problem.

A thin layer of algae that's metaphorically greening the ice sheet — it's actually more of a purple brown — is causing the ice, which is already retreating at an alarming pace, to melt even faster.

The algae thrive during the summer months and as they darken the ice surface, it absorbs more heat, which leads to more melting.

Scientists from the University of Leeds, including Canadian geomicrobiologist Jenine McCutcheon, (now at the University of Waterloo) wanted to figure out where the algae get their nutrients.

This is the basecamp where scientists studied the algae blooms and where they get their nutrients from. Every summer, algae blooms cause the edges of the bright white Greenland ice sheet to darken, especially along the western margin in an area known as the "Dark Zone." (Jenine McCutcheon)

The algae also produce liquid water as part of their growth process, which both helps them grow, but also facilitates more melt. 

The team determined that phosphorous was a critical nutrient, and were able to trace the phosphorus to mineral dust from a local Greenland source. This discovery was published in a study in the journal Nature Communications

Given that in the past, ice core samples have shown that past dust deposited on the surface came from far away places, McCutcheon said the algae's local nutrient source is quite concerning. The influx of local, algae fertilizing dust could be increasing.

As our climate continues to heat up, the more the ice will melt, leading to more exposed rock that could provide nutrients for even more algae to grow.

Produced and written by Sonya Buyting

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