Glaciers are eroding the Earth faster than we thought

Glaciers – nature's slow artisans – are silently reshaping the planet's surface, and humans can now measure the process with unprecedented precision.

 

An international team of researchers recently used machine learning to analyze 85% of the world's modern glaciers. The results showed that most of them are 'eroding' the Earth's surface at a rate of between 0.02 and 2.68 mm per year – equivalent to the thickness of a credit card.

The speed of change is incredible

Glaciers have shaped many of the iconic landscapes of polar countries, including Canada – from carving out valleys in Banff, to eroding the topography of Ontario, to leaving fertile soils in the prairies. They continue to shape the planet's surface, but the question is: how fast is it happening?

In a study published on August 7 in the journal Nature Geoscience , geographer Sophie Norris (University of Victoria – UVic) and her colleagues have provided the most detailed assessment to date of the rate at which glaciers erode terrain. This is also the first time scientists have had a global estimate of the future erosion rate of more than 180,000 glaciers.

Using a global machine learning analysis, the team predicted the erosion rates of 85% of modern glaciers. The results showed that 99% of them are wearing away at a rate of 0.02 to 2.68 mm per year, about the thickness of a credit card.

 

Meaning and application

' The conditions that lead to erosion at the base of glaciers are much more complex than we previously thought ,' said Dr Norris. ' The study shows that many factors strongly influence the rate of erosion: temperature, the amount of water beneath the glacier, the type of rock in the area, and even the amount of heat coming from deep within the Earth. '

Professor John Gosse (Dalhousie University) added: ' Because measuring erosion in active glacial environments is extremely difficult, this study helps us get estimates for even the most remote areas of the world .'

Understanding the mechanisms of glacier erosion not only helps with landscape management and environmental conservation, but is also valuable in planning long-term nuclear waste storage and monitoring the global transport of sediments and nutrients .