Roman the Ice Man

Deep beneath the Hintertux Glacier lies a system of ice caves. This fascinating underground complex was discovered by chance by local cave expert Roman Erler. He agreed to give us a tour of the caves and told us what it is like to stumble across a natural wonder.

The top cable car station on the Hintertux Glacier is a busy place at 9am. Here, at 3,250 metres above sea level, a gondola spits out small groups of skiers and snowboarders at regular intervals. As they step out of the cabins most have no idea that they are standing on a natural wonder. Oblivious to what is below their feat, many take a moment to enjoy the hundreds of peaks glistening in the morning sun before launching into the first run of the day.

Unlike most up here we haven’t come to ski. Instead, we are here to marvel at a natural phenomenon no less breathtaking than the peaks that line the horizon. We are met by a tall, slender man wearing sturdy hiking boots. It's Roman Erler. After a brief greeting we walk on a few metres before stopping abruptly in front of an inconspicuous tunnel dug the snow. Roman slips on a powerful headlamp, turns around and suddenly disappears into the belly of the glacier.

Roman Erler: The man who discovered the Nature Ice Palace on the Hintertux Glacier.

How long did it take you to find this tunnel inside the glacier?

I came across it by chance. I was on my way back from a hike on the Olperer mountain and was walking along piste number 5 towards the gondola. That's when I noticed a narrow crevasse on the side of the glacier about ten metres above the ground. I thought to myself: I'll take a closer look.

Aren’t crevasses something you would expect to find on a glacier?

Yes, absolutely. There are many of them. That's what made this particular one so interesting. Piste number five is the steepest ski run on the glacier. Normally the rule is: the steeper the terrain, the greater the tensile forces that cause crevasses. However, here there are no crevasses visible on the surface. That is something that has always puzzled me.

A series of ladders and carved steps take adventurers into the underground caves – with tonnes of ice above their heads.

What did you find?

I approached the spot carefully, built a belay with ice screws and made the hole a little larger with my pick so that I could climb in. Inside it was dead silent. Pitch black. But also so large that the light of my headlamp stretched out into the distance. A few days later I came back with better equipment and ventured further inside. It was then that I realised this is no ordinary crevasse – this is a gigantic system of natural caves.

Who was the first person you showed your new discovery to?

My wife Marlies. She was also the one who convinced me to make the caves accessible to the public. I was originally against it because I knew that cavities in the ice have a limited lifespan. Despite this, we decided the following year to offer a few guided tours for selected groups. Purely out of interest I also measured the cave. That's when I first began to think that there was something out of the ordinary.

My precious! When Roman Erler first discovered the cave, his initial instinct was to keep it to himself. It was his wife Marlies who convinced him to share this natural wonder with the world.Out of the ordinary?

What I mean is that I began to realise that this section of the glacier is not like the rest. At a depth of 25 metres I drilled a hole to see how quickly the ice was sinking – but there was no movement at all. Today we know that the upper part of the Hintertux Glacier stands on permafrost with a temperature of minus 1.9 degrees Celsius. That means the glacier is frozen to the bedrock. This explains why the caves are so stable. This was a totally new discovery. Today I believe that there are other cave systems of this kind in the world, but this is the only one we actually know about.

We have reached the spot where the Roman Erler, a qualified cave and mountain guide, drilled down into the ice. Behind us lie a series of ladders and carved steps; above us stands a layer of ice many metres thick weighing thousands of tonnes. The walls of the ice tunnels smooth as a mirror and as hard as rock. In some sections they are covered with thousands and thousands of crystals: hexagonal, plate-shaped or as sharp as needles. Again and again they open up to reveal caves in which the glacier keeps its most eye-catching sculptures.

Colossal stalagmites, sweeping curtains and twisted columns of ice. The forms seem rigid, even eternal. And yet they are alive, flowing, dynamic. The result of a process that we humans can comprehend only in theory. The enormous forces that formed them remain invisible. The time frames in the field of geology, i.e. centuries and millennia, are so far removed from our own reference points of days, weeks, months and years. 

The caves are constantly changing. If the conditions are right the ice crystals can grow by up to 10 centimetres overnight.

The caves are home to a series of eye-catching ice sculptures. “Nature is the best designer,” says Roman Erler.

So what happened after you had been to the cave a few times?

Initially we didn't know that the cavities would remain stable. That's why we moved forward very slowly, bit by bit. Since discovering the cave I have spent thousands of hours down here. A few years after the discovery there was a nasty letter was sent to us and lots of different authorities claiming that we were putting the safety of our visitors at risk.

What was your reaction?

We sat down with people from the forestry authorities as well as the district governor at the time to find a way to hold the tours in accordance with the law. Ultimately, we ended up using the Tirolean Events Act. We did everything that was required of us. We had a report drawn up on the structural stability of the caves and called in the inspection authorities to certify the electrics we have installed underground. When they tried to measure the conductivity down here, they thought their equipment was broken! The conductivity of glacier ice is almost zero. We even had the fire inspectors here. A fire risk assessment for a glacier! Even the people from the authorities had a little laugh when they saw that.

Our tour is nearing its end, but Roman Erler has only one thing left to show us. For many visitors it is the highlight of the Ice Palace: 3,220 metres above sea level, 30 metres below a ski slope, in the middle of a glacier, there is a lake about 30 metres deep. It is the only place in the world where you can stand-up paddle, boat or canoe inside a glacier.

Skiing on the glacier above, swimming in the lake below – and 30 metres of solid ice in between. Deep inside the glacier there is a lake which continues to puzzle scientists.

Why does the lake not freeze?

Firstly because the ice does not move here due to the permafrost. If that were the case, crevasses would form and the water could drain away. The fact that the surface does not freeze has to do with the water itself. It has a low concentration of ions – and distilled water freezes at lower temperatures than normal water. That's why the water here can be as cold as minus 0.6 degrees Celsius. Normally the water temperature in a frozen lake is around 2 degrees Celsius directly below the ice. That is also the reason why the world's top ice swimmers meet here.

Have you ever swum in the lake?

We once had a film team here. Just before they started shooting a really important bit of camera equipment fell into the water. I stripped naked and went in to get it.

Are there still sections of the caves that are not open to the public?

Yes, only a small fraction of the caves are accessible to the public. The vast majority remains off limits.

Roman Erler has spent thousands of hours making the caves accessible to the public, yet even today most of the underground complex remains off limits to visitors.

Is that because you want to keep a few secrets of the glacier to yourself?

No. We want to protect certain areas for research, so it is important that these are kept intact. You would often have to destroy huge ice crystals or curtains to get any further. That is something I want to avoid. I have already seen things here that no one else has seen before me. Once I drilled into a water pocket. When I came back the next day, the water had drained out and I could see through the hole for the first time. I had tapped into a 25-metre-deep crevasse where countless crystals had formed underwater. That is a sight I will never forget.