As their name suggests, ice caves are tunnel-like features that occur within ice bodies, usually glaciers. They have been known to science at least since 1900, when the American explorer and scientist Edwin Balch described them in his book Glacières or Freezing Caverns. In recent decades, some ice caves have become major tourist attractions.
Ice caves are formed by the horizontal movement of liquid water through glaciers. This movement causes some of the ice to melt. In some cases, the liquid water is produced by melting on the glacier surface; it then descends through a vertical tunnel or moulin to the glacier bed, where it flows out and emerges at the glacier snout. In other cases, geothermal activity provides the heat to melt the ice. Caves can also form on glaciers that terminate in lakes or the ocean; melting at the front of the glacier can proceed under the glacier, sometimes for considerable distances.
Ice caves attract tourists in a number of countries. Norway and Iceland are major destinations for people who wish the visit them, but they are found in other countries as well, including Switzerland, Austria, Russia, Canada, Argentina and New Zealand. The nature photographer Kamil Tamiola entered an ice cave on the north face of an Alpine summit in France at 3,800 meters above sea level. “You need to stay focused, pay attention to every single move and commit yourself entirely to this climb,” he said. He used mountaineering gear, including ice axes and crampons.
Less equipment is needed to enter the ice caves of Lake Superior, which form each winter from seeps in a limestone cave rather than from melting within a glacier. Tourists wear warm clothing and boots, and bring only trekking poles for balance. “It’s just fantastic, ” said Jim McLaughlin, who visited them in 2014. “It’s unique to see water in so many different forms and different colors and the way it’s sculpted.” McLaughlin and the others
In all these countries, the best time to visit ice caves is during the winter. There is a greater risk of collapse from melting at other seasons. Tourists have to bring appropriate gear to enter an ice cave. Helmets, gloves, sturdy boots, and warm layered clothing are often required. Headlamps and kneepads are highly recommended.
There is a sense of urgency about glacier caving, since some of the caves are at risk of disappearing. Bob Krumenaker, the park superintendant at Apostle Islands National Lakeshore, where the Lake Superior ice caves are located, mentioned that people treat ice caving as “a truly endangered national park experience, because, like endangered animals, we can’t predict its future, and it may not be there,” The Sandy Glacier Cave System on Mount Hood in Oregon is also shrinking. In his website From a Glacier’s Perspective, Mauri Pelto writes of the complete disappearance of the caves on Paradise Glacier on Mount Rainier in Washington. For the meantime, though, a visit to an ice cave can provide a striking experience of the interior of a glacier.