Hidden Time: What Glacier Ice Tells Us
Discover the ancient layers in the Morteratsch Glacier
By Juerg Kaufmann, Glacier Photographer and Founder of Glaciers.Today
Have you ever wondered how old the ice beneath your feet actually is when hiking near a glacier? At first glance, a glacier looks like a frozen river. But inside, it holds a story that goes back centuries, even millennia. As a photographer who's been documenting glaciers for over a decade, I've learned to see them not just as icy landscapes, but as powerful time capsules.
A Living River of Ice
The Morteratsch Glacier in the Swiss Alps is one of the most accessible and well-studied glaciers in the region. It flows down from the heights of Piz Bernina into the valley, stretching over 7 kilometers and holding an archive of Earth's recent climate history. From the freshly fallen snowflakes in its upper reaches to the ancient ice layers at the glacier's end, every part of this glacier tells us something about our changing planet.
How Glacier Ice Ages
Every winter, fresh snow piles up in the high alpine areas. Over time and under pressure, this snow turns into firn, and eventually into compact glacier ice. As more snow accumulates, the older layers get pushed down and slowly start flowing downhill. This means the ice at the lower end of the glacier – in what's called the glacier tongue area – could have started out as snow over a hundred years ago.
At Morteratsch, the surface ice layers near the tongue are often dated back to the mid-19th century, which was during the so-called 'Little Ice Age.' Deeper ice layers at the glacier's base – now visible through melting ice caves – can be much older. Scientific measurements date this basal ice to be up to 1,800 years old.
The Basal Layer:
Ice from Another Time
The basal layer is the deepest and oldest part of a glacier – ice that's been buried under hundreds of meters of snow and under extreme pressure for centuries. At Morteratsch, this layer is often exposed in ice caves near the glacier tongue, where meltwater has carved tunnels into the ice. The crystal-clear basal ice visible there is especially dense, bluish, and almost bubble-free in some spots. In other areas, you can see fine networks of trapped air bubbles – tiny atmospheric samples, frozen in time.
Because the ice at the bottom flows super slowly and is protected by the layers above, it sticks around way longer than the ice closer to the top. Samples from Morteratsch show this ice is up to 1,800 years old – that's way before modern history even started! This deep ice layer holds awesome clues about past climates, what the air was like, and the glacier's journey over hundreds of years from where it formed all the way down to the valley.
(Wikipedia).
And the Air Bubbles in the Ice?
If you've ever seen crystal-clear glacier ice with tiny bubbles inside, you're actually looking at ancient air. These bubbles formed when the snow was still porous and gradually got trapped as the ice became denser. So, we're not just standing on old ice – we're also seeing captured samples of the atmosphere from way back then.
These preserved air bubbles help scientists understand how Earth's climate and atmosphere have changed over time. Even the smallest pieces of ice can provide clues about past CO2 concentrations, volcanic eruptions, or air pollution.
The Morteratsch Glacier: A Case Study
The Morteratsch Glacier, located in the Bernina region of the Swiss Alps, really shows us how dynamic Alpine glaciers can be. About 20,000 years ago, during the last Ice Age, it was actually part of the larger Inn Glacier system. As the climate warmed, the glacier started to retreat. Around 14,000 years ago, it still extended into the Bernina Valley, being about 400 meters thick! Then, in the early Holocene, about 10,000 years ago, it almost reached what is now Pontresina. Since then, the glacier has been continuously pulling back, with some fluctuations due to climate shifts. It made its last significant advance during the "Little Ice Age" around 1850, almost reaching today's Morteratsch train station. However, since systematic measurements began in 1878, the glacier has retreated by over 2,600 meters (Wikipedia).
Want to See It for Yourself?
With the glaciers.today project, you can watch live images of glaciers and see firsthand how these massive ice giants change through the seasons. I invite you to explore, learn, and truly listen to the ancient ice – while we still have it.
