Descent Into the Ice

PBS Airdate: February 10, 2004
Go to the companion Web site

NARRATOR: It is the highest mountain in the Alps, but deep inside the icy slopes of Mont Blanc are hidden lakes, a secret water world that is stunningly beautiful, but deadly. A hundred years ago, one of the mountain's hidden lakes burst forth, sending a wave crashing down toward the villages below. Nearly 200 victims were caught by surprise, unable to outrun the flood. Two days later, rescuers were still plucking bodies from the mud. Dozens were found inside buildings ripped open by the deluge.

The chapel, which was damaged but survives today, bears witness to the horrors that took place. Here, historian Jean-Paul Gay looks for clues to a tragedy that no one fully understands.

Ice experts have also come to solve this hundred-year-old mystery. They try to gauge the internal forces of the ice to predict when the next flood will occur. They're descending into frontiers never explored.

LUC MOREAU (Glaciologist): It's an unknown risk that could kill people if a hidden lake were to empty all at once.

NARRATOR: It may be only a matter of time before Mont Blanc faces another disaster. Descent Into the Ice, up next on NOVA.

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Mont Blanc towers above Europe—the apex of France, Switzerland and Italy. But after 200 years of exploration, this mountain is still untamed. It's a vertical landscape where ice laid down in the last Ice Age carves a path through sheer bedrock. These frozen rivers are known as glaciers, but their uneven surfaces filled with teetering ice blocks only suggest the greater dangers that lie within.

Luc Moreau is a glaciologist who lives and works on Mont Blanc. He knows the mountain inside and out.

LUC MOREAU: We're facing one of the great natural wonders of the planet. This mountain makes you realize just how small we humans really are. It's alive, ever-changing, always surprising.

NARRATOR: Luc is joined by Carsten Peter, an ice climber from Germany, who travels the extreme landscapes of the globe, exploring, photographing, and mapping the world's most extraordinary ice caves—some of which are found here.

They're searching for a specific ice cave that the French call a moulin, a water well or deep shaft formed by flowing meltwater on the surface of the ice. Their goal is to descend into this water and penetrate as far as they can go to search for a hidden lake. No one knows how deep, how large, how destructive these hidden lakes can be, or how many there are.

They land on France's largest glacier, the seven-mile-long Mer de Glace to conduct their research.

Today, Luc and Carsten will make their first descent below the slick surface of the glacier to the waters deep within. They'll camp on the ice for several days, but it's not exactly roughing it. Their food has been flown in by helicopter. Meals are orchestrated by Luc's wife, Evelyne, a professional chef.

Luc calls himself a glacionaut. He's well aware of the risks.

LUC MOREAU: Here, we have two kinds of risks: first there are subjective dangers, based on the skill of the climber, then there are objective dangers from the environment itself. To minimize those risks, we've adapted some precautions taken by cavers with crampons, ice axes, ice screws, and a helmet, because once you're inside, there could be ice or falling rock, rushing water, so we need to be, always be, totally alert.

NARRATOR: Sixty feet wide at its mouth, the water well is a vertical cave, tunneling 85 feet down to a deep reservoir fed by two waterfalls. From here, we see the inner workings of a glacier.

Seventy thousand years ago, one large ice cap covered most of the mountain, but now Mont Blanc has about a dozen smaller glaciers that change with the seasons. Since the last ice age, Mont Blanc's glaciers have grown several times, but today they are receding due to climate change. Small fluctuations in the size of a glacier can cause avalanches, mudslides, and ice-fall, endangering the towns and villages below.

But the ultimate danger may be from a hidden lake. They are undetectable under the ice, and the only way to find one is to travel inside the glacier as far as is humanly possible. On the Mer de Glace, the ice is 1,000 feet thick.

Glaciers grow from the accumulation of snow, which transforms into ice and slides downhill under its own weight. The snow melts under the sun's rays, and the meltwater circulates down through cracks and crevasses. On some glaciers, water will find a fault in the surface and plunge downward through the weakness, carving out a deep shaft. These are water wells, and they act as the starting point for tunnels of meltwater that flow inside the glacier.

Having descended into the water well, Luc can see how quickly the meltwater is chiseling into the ice. Over time, the ice shaft will change shape according to the temperature of the water and the strength of the ice.

Today, remarkably, both the ice and water are the same temperature. With the ice close to its melting point, it is unstable and dangerous to climb.

LUC MOREAU: Here the ice is zero degrees centigrade. It's not cold ice. We call it temperate ice that will change its shape with the inflow of water. Over time, the water well will enlarge, the ice will become pitted, and the reservoir may fill up completely. We're lucky to be able to explore this cavity because it's changing every day.

NARRATOR: Depending on the temperature of the ice, the walls they're climbing can vary from the hardness of concrete to the softness of wood—where ice tools can easily come loose.

At the surface of the water, they decide to venture further into a small tunnel to see if it leads to a hidden lake. They have to wait until nightfall to continue their climb deeper into the ice.

Luc and Carsten enter the tunnel 85 feet below the surface of the glacier. In the cold evening temperatures there's less danger of the glacier collapsing on top of them and less chance of a surge of water bursting through the tunnel, drowning them inside.

They risk capsizing in their inflatable raft; it has to be small to fit, and the weight of two men inside is precarious. Falling in these waters would result in hypothermia, so they've fixed ropes to the ice for stability.

This journey is the closest they'll come to understanding the dynamics of the innermost depths of a glacier, where hidden lakes are most likely to form.

LUC MOREAU: The hidden lakes are the least-known danger that we face today from a glacier. We have very little information about the danger because it's so hard to penetrate within the glacier. This water well is the only way to see the interior of a glacier. We can see how water circulates, how it's held back. Is it always flowing? We are not sheltered from a hidden lake bursting. They're impossible to detect, impossible to predict.

NARRATOR: They travel over 250 feet into the glacier, further than anyone has gone before. And they have no idea what lies ahead. Luc is looking for signs of a hidden lake held in place by a barrier of ice. A hundred years ago, the barrier burst and millions of cubic feet of water cascaded down the mountain, drowning the villages below.

The thermal baths in nearby Saint Gervais was where the greatest loss of life occurred. Visiting the now rebuilt spa, historian Jean-Paul Gay has pieced together the moments that led up to the deadly flood.

JEAN-PAUL GAY (Historian): It's 1892, in early July, and there are 300 people staying here—spa guests, but also staff, caterers, chambermaids. It's like a little town down at the bottom of this gorge. They're getting ready for a nice evening at the resort. A pianist has come from Geneva to give a concert that evening.

It is a place where people come for treatment—they come to enjoy the waters. In the 19th century, people ate a lot in France, they liked good meals, and of course this played havoc with their health. And so every year they would come for two or three weeks for the waters of Saint Gervais. They would drink the water, they would take baths, they would take showers to try to improve their health.

NARRATOR: July 11th was a very hot day, and the spa guests sought out ways to cool themselves off at a nearby waterfall.

JEAN-PAUL GAY: The waterfall played an important role on the night of the catastrophe because, as you see, the gorge is very narrow, very enclosed. And when a hidden lake burst from a glacier, a dam formed. The gorge was blocked by boulders and fallen trees. The debris could no longer move. Water built up behind it, thousands of cubic feet of water.

NARRATOR: In a split second, the dam of debris dislodged, sending a wall of horror down upon the resort, smashing the buildings to pieces. A wave of suffocating mud enveloped the lower floors of the spa. And it all happened without warning.

JEAN-PAUL GAY: All of this takes place in the dark of night. They have no idea what is happening to them. The people would have simply been crippled with fear.

NARRATOR: The roar of the floodwaters sent panicked villagers running for higher ground. They were the lucky ones who were among the living at dawn. One woman, swept downriver, saved herself from the mud by grabbing on to the balcony of a collapsing house.

It took two days for victims' bodies to be recovered. Some were washed down to Lake Geneva, 50 miles away. Many were never found.

In the village of Bionnay, nine houses and their 33 inhabitants were swept away. The schoolhouse still stands today, but many of the pupils, at home that night in bed, were drowned. We know who they are because the original school register was found by Jean-Paul Gay.

JEAN-PAUL GAY: Typically, what is written here is, "She finished school and went on to university. He left to work in the fields with his parents." But here, on that date, you can see, "She died in the catastrophe of the 12th of July." There are four kids on this page.

I can see Victorine Bouchard, who was born in 1886, 7th of August—her father was a farmer in Bionnay—so she was six when she died in the catastrophe. And then we can see another child by the name of Bouchard, and indeed, it's her brother—his name was Henri—who was three years older. So there you have it, a brother and a sister who died. Eight from this school lost their lives in the catastrophe.

NARRATOR: The loss of so many lives begs the obvious question, "Might a catastrophe of such enormous magnitude happen again?" The only way to know is to search beneath the glacier for hidden lakes.

On the Mer de Glace, Carsten descends into the water well to see if it will be possible to do an exploratory dive. They've followed one tunnel at the surface of the water, now they plan to go much deeper to look for underwater tunnels that could lead to a hidden lake. Carsten rigs a digital video system on an extended arm to submerge underwater to test the visibility. He wears special goggles that project the recorded image onto the lenses before his eyes. Like a virtual reality video game, he can manipulate the camera without succumbing to the icy water himself. Before doing a real dive, Carsten needs to know how clear the water is and make sure that there are no large cracks that could suck him unwittingly into the glacier.

CARSTEN PETER (Photographer): For me, it's just another world, to dive into another world. You can't see from the outside exactly how, for example, the visibility is, how the crystals, how the formations, how the whole situation is. So it was good to have this preview with the remote TV cam just to judge if the effort of a diving expedition is justified.

NARRATOR: Luc descends with a rock attached to a rope to measure the depth of the water well. This will help Carsten gauge how deep he should be prepared to dive. The weight of the rock should be enough to anchor the rope to the bottom of the shaft.

CARSTEN PETER: Boy, it looks very, very deep.

NARRATOR: The rock hits bottom, and Luc marks the surface level with red tape.

CARSTEN PETER: Twenty-four meters.

NARRATOR: Twenty-four meters, or 80 feet, means this will be a deep-water dive for Carsten. It's the moment of truth. The water well is as safe as it will ever be for a dive.

CARSTEN PETER: Be careful.

NARRATOR: It's just cold enough to keep the glacier frozen, and the water well hasn't yet turned to ice.

CARSTEN PETER: We made a depth measurement. It could be even deeper than 23, 24 meters. The water is quite clear. And for me, it's the first time in the Alps to find these beautiful conditions.

NARRATOR: Armed with this information, they leave the water well, determined to return as soon as they can with their SCUBA gear to take advantage of the perfect diving conditions before temperatures drop.

But in the meantime Luc has a job to do. It's his responsibility to monitor the ice all over Mont Blanc. The towns below hire him to watch for unexpected surges of water coming from within the glaciers. His commute is one of the most beautiful on Earth. He takes a gondola to an elevation of almost 7,000 feet. His dog, Poppy, a husky mix, is always at his side as he ascends to the Argentiere Glacier, the second largest in France. But he'll see this glacier from the inside out.

LUC MOREAU: When I was a kid, my parents took me to visit a cave underneath the Mer de Glace, a popular tourist attraction. And I have to tell you that I remember it vividly. It was pretty surreal, being inside a glacier. This is an environment that makes me appreciate the frailty of man versus the power of nature.

NARRATOR: Luc works for a hydroelectric company, which has built one of the only under-glacier labs in the world. Here, a labyrinth of manmade tunnels extends deep inside the glacier, 35 shafts that harness the glacial meltwater for power.

LUC MOREAU: My work here is to measure the movement of the glacier and determine exactly where the water flows. The water is collected underneath this icefall and then channeled to fill a reservoir down-valley, which produces electricity.

As there are so few sites like this in the world, it's very useful for original research.

NARRATOR: Luc and Poppy have to climb over 600 steps each day to get to the heart of the glacier. Just when one flight is done, another appears at the end of a long tunnel, and finally, a large cavity beneath the ice where a river of melted ice flows over the bedrock. Above Luc is the glacier, 350 feet thick. Here, Luc can measure the movement of the ice with a bicycle wheel mounted on a cantilever. By speeding up his video record, we can see five month's worth of ice flow.

LUC MOREAU: As the glacier slides down the mountain, it spins the wheel. It moves two feet per day, or about an inch an hour. To my knowledge, it's the only instrument that can measure the movement of a glacier from below. Since this is electronic instrumentation, and there's all of this sand and water, we have to check the equipment regularly. It's an extreme environment.

NARRATOR: The wheel is wired to an instrument that plots the speed of the glacier.

LUC MOREAU: We're able to see that, in summer, the glacier moves faster than in winter. That's because the increased meltwater acts as a lubricant.

NARRATOR: Luc can also measure the amount of water flowing under the glacier, and detect any abnormalities in its flow. If a hidden lake were to burst, his instruments would pick up the increase in volume and warn the village below of a possible flood. It's rare that a glacier can be monitored so closely.

Using a fixed camera mounted 650 feet from the ice, Luc has created a one-of-a-kind movie of a glacier as it moves over the course of a year.

One valley to the south lies Mont Blanc's greatest glacier, the Mer de Glace, the sea of ice. Waves of crevasses and undulating ice bands churn up the bedrock below, making the glacier look dirty and gray. At this time of year, any surface water is frozen solid, except at the moulin, the water well that Luc and Carsten explored.

The team flies in their specialized gear for what will be a technically challenging dive at high altitude and in extreme cold. They'll use a combination of cave diving and cold-water diving equipment. A single diver's rig weighs 132 pounds. Carsten is undergoing considerable risk in a new attempt to find evidence of Mont Blanc's hidden lakes.

They return to see that winter has set in. A dive here seems improbable; the recent snows have accumulated in the water well. Luc will have to figure out how deep the snow is and whether he can even stand on its surface without falling through. He's clipped into an anchored rope so he can be pulled out in case he breaks through the snow into the water below.

They're trying to figure out the best place to dig out a hole for the dive. Snow gives way to a layer of ice, but no one knows how thick it is. Luc's chainsaw will be the quickest way of cutting through to an answer. He has to be careful not to flood the motor. The goal is to make a hole wide enough to enter.

One layer of ice leads to another three feet below, and hopefully it's the last.

Diving inside a glacier at 11,000 feet is a risk, but it's the only possible way of locating a hidden lake. To beat the sub-freezing temperatures, they work into the night and finally succeed in cutting a five-foot-wide hole. Carsten shines a light underwater to check the conditions. It's an eerie sight, a frigid pool with just enough visibility for Carsten and his two diving assistants to enter in the morning.

Dawn brings with it a strange sight: men in diving suits, wearing crampons while rappelling into an ice shaft high in the Alps. This will be the first underwater dive ever done on Mont Blanc.

CARSTEN PETER: It will be a little process now to bring all the luggage down, so...we have very heavy diving equipment. Some of these equipments, they weighed more than 50, close to 60 kilograms, so it's really hard work for us.

NARRATOR: The heavy tanks are lowered down first. They're handled carefully because gas under pressure can be highly explosive. The depth of the water requires them to breathe nitrox.

CARSTEN PETER: We dive here with nitrox, this is a mixture, an enriched a certain pressure the oxygen becomes toxic, and so you have to beware, you have to have a diving plan, and you have to behave according to your mixture.

NARRATOR: The mixture has more oxygen than nitrogen to reduce the time they'll need to spend on their way back up to the surface decompressing after the dive.

Zinc oxide applied to the skin acts as a natural insulator.

CARSTEN PETER: Do they have hot water here, Luc?


NARRATOR: Carsten's mask has already iced up on the inside, which will make visibility impossible.

CARSTEN PETER: It's already frozen. And every little thing will freeze now, I think. Okay, just a little bit melts here.

NARRATOR: They wear special dry suits for freezing temperatures.

CARSTEN PETER: The dry suit is absolutely necessary in this temperature. So you are, as the name says, inside is dry. We cannot inflate our dry suit with the nitrox because it's too oxygen-rich, and if we dive with the artificial fibers it could incend, and the oxygen could burn the fiber inside. So we need another gas—it's argon—just to inflate the dry suit. You press here on the suit and the argon is inflated here. This is the deflator.

NARRATOR: Argon is also an excellent insulator against cold. The water temperature is at its freezing point, so the biggest danger is that their regulators, or air valves, will freeze shut.

CARSTEN PETER: Here we are close to the freezing temperature, and if compressed gas expands it cools down, and so the danger of icing is very, very big. So probably our regulators will be blocked. So if we are in the depths, like 20, 30 meters, and the regulator is blocked, we have to change, of course. We have two independent systems, but even the two independent systems could block, so it is very important to have assistance with other divers. So I brought two friends with me. And it's a very serious dive, so it's less risky to do it with experienced divers.


NARRATOR: One of Carsten's regulators has already iced up. A regulator that's frozen open will allow all the precious air needed for the dive to escape.

Carsten will use the rope as a lifeline to find his way back up. He descends into the water well, to take an initial look.

CARSTEN PETER: The first impression: it's quite big and you can't see to the end, and it's easy to lose orientation, so we have to be very, very careful for the dive—very careful. Safety is very important. Can someone bring my video camera? Put it here on the...okay, thank you.

NARRATOR: Carsten's companion divers have done extensive dives in extreme cold. Their combined experience will be the greatest guarantee of safety. But their regulators keep freezing open with gas leaking out before they've even looked below the surface.

Each diver has a lifeline to follow as they descend into the unknown. The visibility is marginal, due to a high concentration of ice crystals mixed into the water.

One of Carsten's assistants checks his handheld thermometer and records a water temperature of minus zero-point-seven degrees Celsius. It's remarkable that the temperature is actually below freezing in a pool of water. They're suspended in the balance where glacial waters lie—between liquid and ice.

What they're seeing is a cross-section of glacial ice. The white walls are frozen snow with air bubbles, and the dark striations represent pure water that has frozen solid. They're looking for cracks or tunnels where the water might be escaping from the shaft. From where they are now, close to the bottom of the water well, the fear is that a slight movement of the glacier or crack in the ice could open up tunnels that will suck them into the glacier.

A wrist compass helps prevent disorientation in the murky water and a sketch pad is used to map the shape of the water well.

It looks like it's completely closed, simulating what a hidden lake would look like, but much smaller. It's an entirely new perspective on what lies within the glacier.

LUC MOREAU: If you want to understand how a glacier behaves, it's important to spend the time observing them, measuring them. We're lucky to be studying a phenomenon still not well-understood.

NARRATOR: But formations like this are not permanent. As the glacier shifts, small cracks could appear, and over time the water would drain out. But something much more powerful happened in Saint Gervais a hundred years ago, when the ice walls surrounding an enormous hidden lake burst, releasing millions of cubic feet of water.

But today, all is well. Like a Jacuzzi in the ice, the bubbles are a reassuring sign—unless frozen regulators are leaking excess gas.

LUC MOREAU: Eighty feet. That's quite deep.

NARRATOR: Their dive plan has reached its time limit. They have to come to the surface now, or succumb to decompression sickness.

LUC MOREAU: It looks as though they've stopped 10 feet below the surface. If they went all the way to the bottom, beyond 60 feet, they'd have to come up slowly and make decompression stops.

NARRATOR: Carsten surfaces first, and it's clear that he's using his backup regulator, as the other one leaks loudly.

CARSTEN PETER: Oh, shit, the ice. Can you please close the bottles? Okay. Okay. Oh, shit. Probably I froze my lips. I had ice in my mouth.

NARRATOR: Carsten's lips, the only part of his body exposed to the icy water, are frozen, and he's worried he has frostbite.

CARSTEN PETER: Okay? Marc, everything okay? He is the only one who is okay, but he had similar problems, too.

NARRATOR: With six regulators among the three of them, only one remained as backup by the end of the dive. The team has gone where no one has been before, diving in a frigid pool of water, 80 feet beneath the ice. They found no cracks or tunnels and they still don't know whether there could be a hidden lake further inside the glacier. There is one other way to find out, but they'll have to return when the weather is warmer and the meltwater on the glacier starts flowing again.

To the untrained eye, the difference is almost undetectable, as winter releases its hold on the Mer de Glace and the relative warmth of summer arrives. The glacier is melting again, and surface water has carved a deep canyon that leads to the water well, still plugged with the winter's snow.

Luc and Carsten are back to conduct an experiment to determine how long it takes water from here to flow to the base of the glacier. Luc is just above the water well and Carsten at the glacier's end where water flows out, some two and a half miles down valley.

CARSTEN PETER: Okay, let's compare our watches. What is your time exactly?

LUC MOREAU: Two o'clock, twenty-five.

CARSTEN PETER: Okay, copy, two o'clock, twenty-five. Are you ready for coloration?

LUC MOREAU: I am ready to put the color in the river.

NARRATOR: Luc pours several tablespoons of flourescene, a high concentration pink fluorescent dye, into the water.

LUC MOREAU: A tiny amount of this substance can color a huge amount of water. So we look for any coloration in the water pouring out of the glacier, at the bottom a few miles down, where Carsten is now waiting. So we will measure the time it took the water to cover that distance.

NARRATOR: If the colored water doesn't emerge at the base of the glacier, there could be a blockage, possibly a hidden lake.

LUC MOREAU: So, Carsten, now the coloration is in the river, so approximately between two and three hours to the front of the glacier.

CARSTEN PETER: Okay, I am prepared for a long afternoon.

LUC MOREAU: The last time this experiment was performed was a hundred years ago when they found it took two hours for the water to travel from here to the bottom of the glacier. Glaciologists were able to show that water takes twice as long to travel inside a glacier than it would in an open stream.

Okay, have a good day.


LUC MOREAU: Carsten, you okay? Do you see something?

CARSTEN PETER: Oh yeah, I am very attentive. No, nothing. Nothing, so far.

LUC MOREAU: Okay, so you call me when you see something.

NARRATOR: Not knowing if a huge pocket of water is forming inside a glacier that hangs above a village is unnerving for Luc and the communities that live around Mont Blanc.

Uncertainty is something that ice experts have to live with, and there's no way of knowing whether the 1892 disaster at Saint Gervais was the last of its kind. At the time, scientists and rescuers did everything they could. The very next day, alpine guides from Chamonix were up at the outburst point, and what they found was astonishing: a hole left by the explosion of the hidden lake out of the front of the glacier. When the water drained out all at once, the roof of ice over the hidden lake collapsed, leaving a perfectly round sinkhole in the ice.

Scientists then spent years examining the glacier and came up with a solution to try to prevent the disaster from happening again. Two drainage shafts were driven through the mountain to relieve the ice of any trapped water. The drainage shafts are still maintained. Ice is scraped out of the tunnel every five years, so water can easily flow out of the glacier in the warm summer months and be diverted away from the towns below.

But no town in the Alps is completely safe. Small pockets of water burst all the time, and there's no way to rule out the threat of larger, potentially damaging hidden lakes. The best safety measure would be to find a way to predict where they are, as Luc and Carsten are trying to do.

CARSTEN PETER: Luc for Carsten? Luc for Carsten?

LUC MOREAU: Yes, Carsten?

CARSTEN PETER: The color is arriving.

LUC MOREAU: Yes? Super. Perfect, Carsten.

NARRATOR: The dye takes two and a half hours to reach Carsten, and the speed indicates that there's probably no hidden lake to obstruct the flow—at least for now.

Having completed their research, Luc and Carsten rope up to climb the last 5,000 vertical feet to Mont Blanc's summit. Luc has been there twice, but Carsten has never had the opportunity to climb the mountain. They start from the Mer de Glace and take a route that travels directly up the glacier, passing giant ice blocks, caves, and formations caused by the rays of the summer sun. Rising head and shoulders above the surrounding Alps, the snows of Mont Blanc are becoming increasingly unpredictable. As global temperatures rise, no one can say with certainty what will happen to the glaciers and what effect climate change will have on the hidden lakes within.

LUC MOREAU: If we had all the scientific tools to detect a hidden lake, it would be very useful, because hidden lakes are the most unknown phenomenon in the Alps. Luckily they're very rare, so today it's not a huge risk. But it's an unknown risk that could kill people if it were really a hidden lake that emptied all at once, because there's a lot of people downstream from the glacier. If we could see it, we could better understand the phenomenon—how it's created, how it evolves, and then how it can become a hazard.

NARRATOR: In this quest for understanding, scientists push themselves to the limit. They explore the tunnels formed by rushing water deep within a glacier, they penetrate down to the bedrock in manmade shafts to plot the speed of slowly moving ice. It's a dangerous business, and no one knows whether it will solve the mystery of the unpredictable waters of Mont Blanc.

Over 300 people will reach the summit with Carsten and Luc today, a reminder that greater numbers are visiting Mont Blanc. The sudden rupture of a hidden lake could affect greater numbers of people than ever before.

Glacial hazards take many forms. On NOVA's Web site, see satellite images of a lake forming high on an Italian glacier, an avalanche that buried a Russian village, and more. Find it on

To order this show or any other NOVA program, for $19.95 plus shipping and handling, call WGBH Boston Video at 1-800-255-9424

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Descent Into the Ice

Written, Produced and Directed by
Liesl Clark

Program Executives, France 5
Ann Julienne
Jacques Angerie

Executive Producer, Granada
Robert MacIver

Executive Producers, SWR
Walter Sucher
Rolf Schlenker

Series Producer
Liesl Clark

Consulting Producer
David Breashears

Narrated by
Jeremiah Kissel

Associate Producers
Marty Johnson
Rob Meyer

Edited by
Stephanie Munroe
Jean Dunoyer

Thierry Machado

Sound Recordist
Erick Ferroud-Plattet

Additional Camera
Sylvain Maillard
Carsten Peter
Luc Moreau

Ilia Jossifov
Ray Loring


Stills Animation
Frank Capria

Translation Voices
Jack Ryland
Peter Newman

Assistant Editor
Hamilton Jones

Online Editor and Colorist
Mark Steele

Audio Mix
John Jenkins

Production Managers
Ann Arnold
Diane Riethof

Assistant Director
Matteo Rivoli

Sylvain Bardoux

Mountaineering guides and rigging
Denis Ducroz
Michel Pellé

Technical assistance
Maël Lamberton

With the scientific participation of
Luc Moreau
Carsten Peter
Jean-Paul Gay

Archival Material
Jean-Paul Gay
Luc Moreau
Tele M1
Archive Photos/Archive Films

Special Thanks
Pascal Brun
Renzino Cosson
Bertrand Daubord, Société Electricité d'Emosson
Martin Funk, ETH
Christian Gauzens
Hans-Rudolf Keusen, Geotest
Idaho Public Television
Mabel TV
Evelyne Moreau
Massimo Pasqualotto, La Région Autonome
de la Vallée d'Aoste
The city of Chamonix
The city of St Gervais
Jean-Marc Peillex
François Valla, Cemagref

With the participation of
Le Centre National de la Cinématographie
CNRS Images/media

For Gédéon and SWR

Bertrand Jenny
Joachim Knaf

Produced by
Gédéon Programmes
Schwenk Film

Executive Producers
Stéphane Millière
Hartmut Schwenk

NOVA Series Graphics
National Ministry of Design

NOVA Theme
Mason Daring
Martin Brody
Michael Whalen

Closed Captioning
The Caption Center

Jonathan Renes
Diane Buxton

Senior Researcher
Ethan Herberman

Production Coordinator
Linda Callahan

Unit Manager
Lola Norman-Salako

Nancy Marshall
Gabriel Cohen-Leadholm

Legal Counsel
Susan Rosen Shishko

Post Production Assistant
Patrick Carey

Associate Producer, Post Production
Nathan Gunner

Post Production Supervisor
Regina O'Toole

Post Production Editor
Rebecca Nieto

Post Production Manager
Maureen Barden Lynch

Supervising Producer
Stephen Sweigart

Producer, Special Projects
Susanne Simpson

Coordinating Producer
Laurie Cahalane

Senior Science Editor
Evan Hadingham

Senior Series Producer
Melanie Wallace

Managing Director
Alan Ritsko

Senior Executive Producer
Paula S. Apsell

A NOVA/WGBH, La Cinquième, Südwestrundfunk, Gédéon Programmes, Meridian, and NHK Co-Production.

"Mont Blanc" © 2003 La Cinquième, Sudwestrundfunk, Gédéon Programmes

"Descent Into the Ice" © 2004 WGBH Educational Foundation

All rights reserved

Descent Into the Ice

Vanishing Into Thin Air

Into Thin Air

Glaciers are shrinking worldwide. Does it matter?

Glacier Hazards From Space

Glacier Hazards
From Space

View satellite images of glaciers both before and after dangerous events.

Outfitting an Ice Climber

Outfitting an
Ice Climber

Click through an ice climber's technical wardrobe.

Life Cycle of a Glacier

Life Cycle
of a Glacier

Follow a snowflake as it lands on a glacier and goes for a prolonged ride.


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