Some of the perennial ice in glaciers have a history as long as 100,000+ years, during which it is common to see periods of ice expansion or retreat, and during which sediment, biological remains, and air are trapped and preserved intact. When we look at a glacier, we are looking at the history of the earth, each trapped air bubble could be the same one that mammoths breathed.

The Rhone Glacier currently has a length of about 7 kilometers and a width of about 1000 meters, covering an area of 15.9 km ². This ice giant is located among the highest peaks of the Swiss Alps, starting at 3630 meters above sea level, and from it comes the Rhone, one of the most important rivers in Central Europe. Over the past 120 years, the Rhone Glacier has retreated about 1300 meters, leaving behind a trail of bare rock. To slow down its melting (which nowadays is about 2% of its mass each year), part of its surface is covered with geotextile sheets, which are effective, but very expensive.