The Monitoring of Glacier Elevation Changes with Pléiades Neo

Challenge

Glaciers are particularly vulnerable due to the climate changes and the challenge is to find the best way to measure and calculate elevation changes accurately.
Several methods for measuring these elevations already exist, and satellite imagery has been used for several decades with SPOT and Pléiades.
Through the Pléiades Neo Challenge, the CNRS glaciologist Etienne Berthier measured the impact of 2022 heatwaves in the Mont Blanc area.
In this research, the glaciologist used 30cm Pléiades Neo imagery to determine the consequences with precision.

Solution and Results

Four stereo pairs were acquired with Pléiades Neo between September and October 2022, right after the intense summer heat waves. A mosaic was created to cover the entire Mont Blanc area.

Digital elevation Models (DEMs) were generated without control points at a ground sampling distance of 4 m. They are coregistered to a reference DEM on the stable ice free terrain to minimize elevation differences and they are differentiated to obtain a map of the elevation changes on glaciers.

This map of elevation reveals changes from August 2012 to August 2021 :

• Glacier tongues (in red) were thinning mostly in their lower elevations and the upper parts were resisting quite well
• Drastic acceleration of the mass loss was observed in the last year

Benefits

Very high resolution stereo images from Pléiades Neo are an efficient way to measure the constantly evolving glacier topography.

Pléiades Neo enables the monitoring of climate change’s impacts on glaciers and the resulting consequences on sea levels and water resources.

Data accessibility remains the main bottleneck to apply these methods at global scale and ensure the continuity of the glacier high-resolution monitoring from space.

Organisation involved