Explore, question, create: the A23a iceberg at the heart of an indisciplinary experiment
Every year, CentraleSupélec students devote a week to projects related to their training. It’s an intense interlude where you can get your head out of the equations and into the real world. This year, I once again had the pleasure of supervising a group working on terrestrial observation applied to the cryosphere, alongside Laurane Charrier (IGE — Institut des Géosciences de l’Environnement, Grenoble/CNES).
Objective: learn, create, experiment!
This is not a classic course. The idea is to immediately invest acquired knowledge in a high-stakes subject, while cultivating an open and creative approach. Yes, it’s possible to combine scientific rigor with freedom of exploration, and have fun while learning.
Students were thus encouraged to mobilize all their skills: scientific, of course, but also artistic, narrative or audiovisual. Because a good researcher is also someone who knows how to share his discoveries and engage his audience.
Here’s a summary of the adventure of five of them: Clément Larue, Florent Maunas, Rita Ouvrelle, Marie Chatel Niemann, Aloïs Jose, on the subject of the A23a iceberg.
The A23a iceberg: a drifting colossus
Let’s talk about the hero (or rather villain) of this story: the A23a iceberg, currently the largest in the world. An ice behemoth that directly threatens the island of South Georgia, a veritable biodiversity sanctuary.
The problem? A floating wall that could disrupt the access of sea lions, penguins and other marine species to their feeding grounds. By altering currents, food availability and feeding routes, A23a could have a significant impact on the local ecosystem. In short, an event that shows just how intimately cryosphere and biosphere are linked.
What the students achieved: seriousness and fun
🔬 Scientific side:
- Access to tracking data: follow the trajectory of the iceberg and understand how this valuable information is obtained.
The trajectory of iceberg A23a from its calving to its progression toward South Georgia. The map shows satellite tracking points, allowing for analysis of movement speed and directional changes influenced by currents and wind. (https://www.scp.byu.edu/data/iceberg/default.html)
- Analysis of Sentinel-1 and Sentinel-2 sensors: detect the iceberg using Copernicus satellite data.
Visualization of the first structural changes in iceberg A23a as it exits a calm, protected marine area. Each color corresponds to a distinct date.
Monitoring the transformations of iceberg A23a in open water, where increased exposure to ocean currents and extreme weather conditions accelerates fragmentation and melting. Each color corresponds to a distinct date.
- Segmentation and surface estimation: measure the evolution of this ice colossus.
- Melt modeling: cross-reference data on air temperature, water temperature, the geographical location of the iceberg, and its exposure to waves, and correlate them to estimate the speed of its melt (or not).
The conclusion of this short study is the following:
The rise in water temperatures appears to be the main factor behind recent periods of accelerated melting. However, between October 2023 and January 2024, it was probably wave action — when the iceberg left a calmer, protected area — that caused the first notable acceleration. Waves promote the mechanical erosion of ice walls and increase heat exchange. As for air temperature, its influence remains limited, probably because the iceberg is mostly submerged, making basal melting (from below) more significant than surface melting.
Graph illustrating the decrease in iceberg A23a’s surface area over time, alongside variations in water temperature. the two last periods of accelerated melting are correlated with temperature increases
🎨 Artistic and communication :
- A colorful news program (with passionate journalists — special mention to Rita! ).
- A delirious video clip with the means at hand (because science is also about emotion and storytelling — and there’s a lot you can do with limited resources).
- A humorous comic strip (so well done that I translated it into English!).
💡 All with a clear objective: to raise awareness and bring people together around this issue by making science accessible and engaging.
And now ?
The collision could happen in the next few days… suspense!
Will the penguins have a Plan B? Will the iceberg decide to turn back out of politeness?
To be continued… and in the meantime, bravo to the students for their commitment and creativity! 🎉
