Drone Research Finds that Glaciers in the Pyrenees Mountains Are Disappearing as the Climate Warms

BY Zacc Dukowitz
14 October 2021

Climate change researchers from the Pyrenean Institute of Ecology recently issued a study that uses drone data to look at how much glaciers in the Pyrenees Mountains have melted over the last decade.

Using imagery and LiDAR data captured by drone and 3D models created from drone data, the researchers concluded that the glaciers are melting at a rapid pace, and might soon disappear—in fact, some smaller glaciers did disappear over the course of the study.

Image source

The Pyrenean glaciers found in the Pyrenees Mountains, which runs between Spain and France, are the biggest glaciers in southern Europe.

The conclusions from the study have serious implications about how fast other glaciers and ice masses throughout the world might also be melting due to the warming climate.

What we are seeing here is an advance warning of what may happen in other mountains, like in the Alps. Their glaciers have much more mass and entity, but we are showing them the way.

– Jesús Revuelto, Post-Doc at the National Center for Meteorological Research

How the Research Was Conducted

Researchers studied the glaciers on the Pyrenees Mountains from 2011 to 2020 using LiDAR data and visual data collected by drone, as well as using data from high-resolution optical satellites.

To conduct the study, researchers compared two datasets, both of which had been collected by drone.

[Related read: Drone Mapping Helps Indigenous People Impacted by Climate Change in Panama Find a New Home]

The first dataset was taken in 2011. In both October and November, the Spanish National Geographic Institute flew several data-collection missions over the Pyrenees Mountains, amassing LiDAR data about the glaciers there. Among climate scientists, LiDAR is known to produce high-resolution data for glacier surface elevation changes.

From the data collected in 2011, 24 glaciers were mapped in total. Researchers used this data to get measurements of the surface elevation of the glaciers in the Pyrenees, creating high resolution Digital Elevation Models (DEMs).

In 2020, researchers did a second round of data collection, flying several missions from August to October to collect LiDAR and visual data. The 2020 data was then processed with Pix4Dmapper to create dense 3D point clouds of the glaciers.

A DJI Mavic 2 Pro flying in the snow (Image source)

Here are the drones the researchers used for the 2020 mission:

  • A senseFly eBee-Plus fixed wing drone
  • A senseFly eBee-X fixed wing drone
  • A DJI Mavic 2 Pro quadcopter

The two fixed wing drones came with a senseFly S.O.D.A. digital camera, and had GPS receivers that supported RTK (Real Time Kinematic) or PPK (Post-Processed Kinematic) positioning systems, which allowed for positioning accuracy of about two inches.

Changes Observed to the Glaciers

When researchers compared the data taken in 2011 with that taken in 2020, they found that the 24 glaciers they’d been following had shrunk by an average of 23.2%, and that three of them had almost completely disappeared.

Overall, the thickness of the glaciers decreased by an average of 20 feet over the nine years of the study, shrinking at an average rate of about 2.6% per year. The areas where the glaciers had melted the most were concentrated at higher altitudes, at an elevation of between 1.7 miles and 1.85 miles.

Comparison between the 2011 and 2020 glacier areas (the black line is the 2020 area)

The images above provide a quick way to visualize this loss—as you can see, the amount of mass the glaciers lost is significant.

Glacier shrinkage in the Pyrenees and wastage have not slowed down in the last few years . . . Pyrenean glaciers are in a clear imbalance with the regional climate, and will likely disappear in the next few decades.

Toward an Ice-Free Mountain Range: Demise of Pyrenean Glaciers During 2011–2020

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