The Patagonian wind was already lashing at us even before we reached Torres del Paine National Park. From the catamaran’s deck, in the distance, a gigantic ice block was drifting. Its size was enormous, as tall as a four-story building, and its bluish shape contrasted with a gray sky. We knew the retreat of the glaciers was progressing at an alarming rate, but seeing and hearing it was another story entirely. We were not there just like simple spectators; our mission was to understand these collapses before they became the norm.
We spend months preparing for this moment. Our objective was to install infrasonic and seismic sensors on one of Patagonia’s largest glaciers: The Grey. This expedition was part of an international project destined to investigate the parameters invisible to the naked eye, those that can only be heard, behind the massive ice calving events.
As a physicist who works with acoustic measurements in extreme environments, I had just finished studying volcanic eruptions and its silent echo in the atmosphere. Right now, the challenge was different: Interpreting the language of ice, translating into data the sounds that the human ear can’t sense, but which foresee colossal events.
The Grey glacier isn’t just a natural beauty symbol, but also a living warning. Every block that is detached, every distant howl that cuts through the ice and wind is a sign of a system that is becoming unstable. Within those inaudible sounds that we set out to record—acoustic waves below 20 Hz— hidden signals reveal the physical mechanism behind glacial retreat.
This expedition was, in many ways, a race against time: Against the thawing, against climate change, and also against the extreme conditions themselves that make the scientific job in this region a continuous challenge.
Although the wind was blowing constantly outside, there was another storm inside me as well. Being in charge of such a significant expedition for the first time, the anxiety of ensuring its success had been weighing on me well before our departure. Patagonia doesn’t forgive mistakes, and I felt the weight in every decision. Added to that was the pressure, more silent but persistent, of having to demonstrate that my voice deserved to be heard, in a scientific environment that still drags gender inequalities. Every day, between the logistics, the tiredness, and the cold, I also carried the burden of holding my ground and leading without hesitation, even though deep down I was afraid I wouldn’t measure up. That tension stayed with me throughout the entire expedition, gradually turning into strength, as nature, my co-workers, and the equipment we were setting up reminded me why I was there.
This chronicle offers a snapshot of the challenges, discoveries, and defining moments of an expedition along the shifting frontier of an evolving world.
From the “Los Cuernos” campsite, the first light of day casts an orange glow on the west face of the massif. The scene, as brief as it’s unforgettable, is a dramatic contrast between the warmth of the sun and the stormy sky typical of southern Patagonia. Credit: Claudia Sánchez (Università di Bologna)
Day 1-2: Surveying the terrain and first attempts
Since sunrise, the Patagonian wind reminded us that working in these conditions wouldn’t be easy. The sailing to the installation site wasn’t confirmed until an hour before departure, since the plans could change anytime depending on the wind’s intensity. In that first moment, anxiety was consuming me. I knew that my role as a researcher involved more than just doing scientific work, but also handling my team and making sure that every decision was the right one. It was my first time on such a significant expedition, and I couldn’t let my doubts hold me back. The pressure was intense, and even more so knowing that my voice—as a woman in a field historically dominated by men—had to be heard loud and clear. Every step had to be determined, every word spoken with conviction, although deep down I felt that uncertainty was a weight pressing down on me.
Finally, we managed to board with our equipment. The captain had to find a strategic landing point, avoiding the need to go through creeks or climb over rough terrain while carrying all our equipment. Every decision was crucial for saving time and effort in such a hostile environment. However, the ship was unable to dock at the designated location due to shallow water, forcing us to quickly modify our plans. We headed to the eastern face of the glacier, where a small motorboat would take us the next day to the WEST front, the area that most interested us because of its proximity to the glacier. Even as we managed to adapt, the weight of time never left us.
Less than 400 meters from the imposing western face of the Grey glacier, the team sets up base camp. Credit: Claudia Sánchez
The first installation attempt failed, so we decided to relocate part of the equipment to a more accessible area, which led us to include the EAST front in our measurements. The equipment’s weight, the uncertainty, and the cold resonate with the spirits. We knew that Patagonia doesn’t give you second chances easily. With the assistance of travel agents, we finally managed to arrive and set up a camp, though it took a lot of effort: the gusts of wind kept knocking us over, and setting up the tents for the night became a challenge in itself. During those hours, the pressure continued to weigh on me. I knew I had to keep going, but the feeling of constantly being on the edge of failure kept me on my toes. There were times when I wondered if everything would work as planned, if the equipment would be functioning properly, or whether my doubts would be evident to my co-workers.
Day 3-4: Infrasonic and seismic sensors
The pressure sensors are strategically buried and reinforced with stones to minimize the wind vibrations. They began to pick up sounds inaudible to the human ear but essential for understanding the mechanism of the ice collapses. The nerves were still there, persistent, but successfully installing the first equipment gave me some peace of mind. Meanwhile, the seismic sensors, anchored in solid ground, were ready to record even the slightest vibrations, allowing us to analyze the calving dynamics with high resolution. However, each day brought new challenges, and the internal pressure didn’t subside.
Striking a balance between technology and environment, members of the crew protect with stones a pressure sensor of the Università Degli Studi di Firenze. The Patagonian wind forces you to think through every move: here, science moves at nature’s pace. Credit: Duccio Gheri (INGV Pisa, Italia)
At six in the morning, we witnessed the first collapse: a massive chunk of ice broke off with such force that it triggered a tsunami on the lake, whose waves continued for at least 10 minutes. Throughout the day, we kept a close eye on the glacier, and before 5:00 p.m., another two gigantic collapses occurred, an image as breathtaking as it’s unsettling. At that moment, the doubts became a mix of amazement and responsibility: the data we were gathering was very important, but at the same time, the magnitude of what we were witnessing left me speechless. But time was against our odds, with a three-day storm rapidly approaching, the boat came to pick us up, forcing us to head back to base camp on the EASTERN front of the glacier. While the installation’s progress was a relief, my anxiety only grew, as the storm forced us to speed up our plans, ensuring everything was ready on time and the setup could function on its own.
Day 5-9: Waiting at base camp
With everything in place, all that was left was to wait. Along with my Italian co-worker, we took the opportunity to go trekking through Torres del Paine National Park, a place where nature reminds you how fragile and powerful it is, all at the same time. You feel tiny in a constantly changing landscape, while the steady and timeless mountains instill a sense of permanence. In that vast area, something inside me began to calm down. The mountain, the wind, the glacier… everything went on as usual, and I, despite my fears, began to understand that my job wasn’t determined by my anxiety, but by precision and patience. The pressure was still there, but somehow, the beauty and power of nature gave me the respite I needed.
Day 10: Final adjustments and departure
The day before boarding the boat, we retrieved one of the most distant cameras; its retrieval was the most challenging part, requiring a two-hour hike through Patagonian rain and wind. Later, we dismantled the infrasonic array and the seismometer at the EAST front at the same location. By that afternoon, all the equipment was ready for loading, as another storm was forecast, which would have made it difficult for the boat to leave the port. As we coordinated the final steps, a wave of relief began to wash over me. The wind and cold were relentless, but we managed to complete our mission with precision and speed. It was an indescribable feeling to confirm that the infrasonic array at the most dangerous and remote site (Front 1 – West) was still working perfectly and recording data.
The data we had collected was there, ready to be analyzed; I felt we had achieved something significant, not only for science but for the team and myself. I had overcome my fears and doubts, proving that, despite the adversities, my resilience remained intact.
View of the Grey glacier’s EAST front. From above, the Grey glacier reveals its full splendor. Its tongue stretches for nearly 30 km from the Southern Patagonian ice field to Lake Grey. The lateral moraine stands as a reminder of decades of glacier retreat. Credit: Duccio Gheri
Preliminary results
Initial sensor analysis
Initial data confirmed that infrasonic sensors and seismometers recorded multiple ice calving events. The infrasonic array of the west front captured low-frequency signals related to collapses, while the optical cameras made it possible to correlate the event with images. Through this data, we have begun to analyze and more clearly understand the dynamics behind these phenomena, which, while still complex, become more visible with every new finding.
Scientific consequences and future expeditions
These results reinforce the importance of studying the dynamics of glacier retreat, a phenomenon that not only affects the Patagonia region but also has global implications. In future expeditions, it will be essential to install more sensors at strategic points, expanding the monitoring network and improving equipment stability in such challenging terrains. Furthermore, the integration of atmospheric and satellite measurements will allow for a more comprehensive and detailed analysis, opening the door to new studies on glacier behavior in a changing climate.
Climate change impact
The fast retreat of the Grey glacier provides tangible evidence of climate change in the region. The ice calving events, which are becoming increasingly frequent, reflect the ecosystem’s fragility and how it’s being altered by anthropogenic causes. The data obtained during this expedition not only improves our understanding of the physical processes behind these events but also contributes to the global comprehension of the climate change impact. Each ice calving event serves as a reminder of the rapid pace at which our planet is changing.
As the catamaran sailed away, I looked for the last time at the Grey glacier. I knew I would never see it the same way again. Every block that broke away was a page torn from the history of our planet. And we were there to hear its silent cry, to witness a process of transformation that, while inevitable, leaves a profound mark on those of us who observe it. The expedition had come to an end, but the knowledge gained, the responsibility to share it, and the resilience it had strengthened within me moved forward, like a constant and urgent call that I couldn’t ignore.
View of the glacier’s west front from the shore of Grey Lake. A stunning wall of ice stretches along Grey Lake, framed by rocky formations and the snow-capped peaks of the Paine massif in the background. Credit: Claudia Sánchez
At Fundación Glaciares Chilenos, we are deeply grateful to you, Claudia, for your incredible willingness to share and let us experience this powerful and honest story firsthand. Your scientific and human perspective, filled with courage, allowed us not only to know the challenges of scientific work in harsh environments but also to feel the weight and importance of every decision, every progress, and every piece of data collected. Thank you very much.
Crew member in front of the Grey glacier. Behind them, the glacier’s west front, a wall of ice over 30 meters high, evidences the dynamics of glacial advance and retreat. In the background, the Paine massif stands out as a geological landmark. Credit: Duccio Gheri
Installed seismometer in the west front of the glacier. Credit: Claudia Sánchez
Dr. Duccio Gheri prepares the monitoring equipment on the shore of Grey Lake. The equipment includes pressure sensors, cameras, GPS positioning devices, and batteries, all housed in watertight cases to withstand extreme environmental conditions. This logistical deployment is key to studying the dynamics and evolution of the Grey glacier. Credit: Claudia Sánchez
Crew member configuring the equipment in front of the glacier. Credit: Duccio Gheri
First image of the infrasonic signal captured on the second day of installation during a major collapse. Credit: Claudia Sánchez
February 2025 Field Team, from left to right: Dr. Duccio Gheri (Istituto Nazionale di Geofisica e Vulcanologia – INGV Italy), Edgardo Casanova (PhD student, University of Magallanes, Chile), Dr. Claudia Sánchez (Università di Bologna, Italy). Credit: Claudia Sánchez
Featured photo:
- Grey glacier. Credit: Claudia Sánchez.
Research team
- Edgardo Casanova. University of Magallanes, Chile.
- Claudia Sánchez A. Alma Mater Studiorum, Università di Bologna, Italy.
- Duccio Gheri. Instituto Nazionale di Geofisica e Vulcanologia, Italy.
- Leoncio E. Cabrera. Pontifical Catholic University of Chile
- Sergio A. Ruiz. University of Chile.
- Bertrand Jean-Maurice. University of Chile.
- Gino Casassa. Chilean Antarctic Institute (INACH).
