My first encounter with the glacier compressed air bubbles was in 2004 visiting Torres del Paine national park in Chile.
On the trip we decided to take a small boat to see Grey Glacier from a close distance. The travel is about 1.5 hours through a very choppy wave lake till you see the majestic blocks of ice. This rocky movement produced waves hitting the front windshields creating curious designs that I photographed. While changing roll film from the camera, I noticed that some people were filling a form. They explained that it was for people that would be hiking through the glacier, and that if I was interested.
One hour later I was adjusting the crampons to my boots and started trekking with a group of tourists. The owner of the trekking agency was on this trip, seeing the large and heavy equipment, decided to be my personal guide. This enabled me to move freely and stop as long as I needed to take photographs.
On the multiform ice terrain, I saw a large hole, which I later learned it was called Moulin. Had to descend with the rope and lot of effort to have the crampons pressed against the sides of the hole. Taking many images, changing roll film and sustain the camera and tripod to fall far below was a difficult task. These compressed air bubbles images were published on my August 2018 blog post In a Moulin at Grey Glacier.
Twelve years later I would be taking similar images, but from a very comfortable angle, however avoiding tourist to interfere.