Capturing The Sound Of Disappearing Glaciers

Sound recordist Thomas Rex Beverly describes his groundbreaking work in one of the world’s most awe-inspiring wildernesses.

What sound does a glacier make? To the uninitiated this may seem like a ridiculous question because one imagines they are simply silent expanses of ice. But that’s not the case. They make all kinds of sounds covering a huge dynamic range, from cracking and popping to booming and tinkling and a multitude of sounds in between. Indeed, they are so noisy that they almost seem alive and breathing, possibly even talking to us in some alien language that we don’t understand.

Thomas Rex Beverly capturing the sounds of disappearing glaciers

Capturing the sounds of these icy wonders is something that nature sound recordist Thomas Rex Beverly is passionate about. Normally resident in Philadelphia, USA, Thomas studied music composition and audio engineering at university and thought he was on course for a career in teaching until he discovered recording outdoors. At that point he switched to field recording and now travels the world recording wildlife, weather events and a whole host of natural features. Thomas makes a full time living as a nature sound recordist and his recordings have been used on numerous high profile film, TV and video games projects.

Heading to Greenland

Having already recorded in Alaska, Norway and Iceland, Thomas recently ventured to East Greenland where he spent two weeks documenting glaciers for his own sound library.

“I have been captivated by them for a long time and Greenland was a big location on my bucket list because it has so many diverse examples of glaciers,” he says. “I assumed they would make some sounds, but they were surprising in a whole lot of ways. They sing, and I find it amazing. They are like slow motion thunderstorms, and you can't help but be awed if you get to witness their beauty and natural power first hand.”

The main aim of Thomas’s trip to Greenland was to capture the sound of ‘calving’. This is the process where huge chunks of ice break off from the front of the glacier to form icebergs. It is usually accompanied by loud cracking or booming sounds and the entry of the ice into the water often causes large, hazardous waves.

“It is like birthing an iceberg, hence the term calving,” Thomas explains. “These are not everyday events, so this isn’t something everyone gets to hear. The volume of the sound depends on your proximity to the glacier and there are many different types of calving, each of which has its own sound. For example, smaller calving events are more like an avalanche and make a roaring sound, while others are like gunshots as pieces of ice crack and fall. Sometimes massive chunks will break off and they are so loud that it sounds like you are turning on a waterfall. You go from nothing to this incredible roar as the ice displaces the water. You hear the thunder and the roar for up to five minutes. It is quite extraordinary.”

Greenland Thomas Rex Beverly Capturing sounds of disappearing glaciers

Kit and Caboodle

Working in extreme conditions requires plenty of forward planning to ensure you have all the equipment you need, plus spares in case anything gets lost or broken.

“There’s a saying that two is one and one is none,” Thomas laughs. “You must have redundancy because you will always break something. I was based in a very remote place – a village called Kulusuk, which has a population of just over 200 people. To get there I flew from New York to Iceland, then from Iceland to the small World War Two airstrip at Kulusuk. I had everything I needed, including batteries and spares. In remote places like this you really do have to think ahead because if you don’t take everything, you go without.”

Thomas took eight different microphone rigs, each containing a recorder, a battery and at least one pair of mics. These included LOM Uši omnidirectional microphones, several Sennheiser rigs with 8000 Series mics, a portable Sony PCM-D100 recorder and hydrophones for recording underwater.

“You can’t predict when a calving event will happen, so I leave microphones out by themselves for long periods of time,” he explains. “They record continuously until the battery runs out – usually about 24 to 48 hours – and I hear what they have captured when I go back to collect them. You might get one calving event in 24 hours or you might get 20 – it just depends on the day.”

When positioning each rig, Thomas put the recorders in a dry bag to protect them and covers the mics with wind protection.

The Windbubble and LOM Uši Pro

“I never take a mic out without wind protection because even in the lightest winds you get buffeting sounds,” Thomas says. “I use Bubblebee Industries products because they are portable, very hard wearing and highly effective in even the most difficult conditions. I have a number of different Bubblebee solutions and on this trip, I used all of them. In fact, many of my Greenland recordings wouldn’t have been possible without their wind protection.”

Bubblebee Windbubbles are his mainstay as he uses them to cover his LOM microphones. They consist of an outer imitation fur shell that creates a bubble around the microphone and prevents wind noise. He also took a Bubblebee WindKiller SE for his Sony PCM-D100 portable recorder and Bubblebee’s Piece-A-Fur, which he used in situations where the weather conditions were especially challenging.

"I use the Piece-A-Fur because its porous back material allows sound frequencies through, while its dense, soft fur deadens friction and reduces wind noise,” he explains. “If the wind was really wild, I’d put the microphones into Windbubbles, then into a Cinela blimp and then wrap the Piece-A-Fur round the whole lot for three layers of protection. The wind protection also helps to shield the mics from moisture and glacial grit, which is even finer than sand and gets into everything. It can really gum up your equipment and I’m always amazed at the amount that comes out when I wash my Windbubbles.”

The different categories of Glacial Sound

During his time in Greenland, Thomas recorded continuously for two weeks and on three different glaciers. This allowed him to capture 700 calving events.

“Some of the glaciers are nearly two kilometres wide and I record those from both sides of the fjord because the sound is very different on each side. Calving was the main event I wanted to capture but there are other categories of sound that I was interested in, too. For instance, underwater sounds around the icebergs and the melodic sound of the ice deep inside the glacial crevices. I was also fascinated by the sound of water resonating inside the glacier. This is very deep down and it makes singing pitches that are really unusual.”

For underwater recordings, Thomas used acoustic mics on land and a stereo pair of hydrophones in the water. This allowed him to capture and compare how an event sounded in each position.

“Underwater sound is like a whole different world, one that crackles and pings and fizzles and booms as the icebergs break up,” he says. “When they are really close to the shore you can hear intense clicking sounds that are like an alien language. The calving events sound like explosions and can be incredibly loud. There was one occasion when I was recording with the underwater mics and I had my headphones around my neck but the volume still cranked up. I heard this booming sound come through the headphone and I physically reacted and said ‘holy shit’ because it was so loud. I thought my outburst had ruined the recording but sound in water moves four or five times faster than it does in air. Because I first heard the boom underwater, I had time to verbally react before the acoustic sound arrived above water. It was fascinating to hear the different speeds of sounds in water versus air.”

Capturing the sound of glacial crevices required imagination as Thomas needed to get his rigs as far down into the crevice as possible. He set up a stereo bar with some selfie sticks, put the recorder in a dry bag and tied it to the bar, then lowered the whole thing 30 metres into the crevice on a piece of rope.

“Crevices make fabulous rumbling sounds,” he says. “On top of the glacier you get sun crust, which is like mojito ice, and when you throw those flakes into the crevice they plink like a marimba or a xylophone. It’s very melodic and hits various pitches, which for a sound person like me is fascinating. I spent a lot of time scraping ice into these crevices. Those were captivating recording sessions.”

Water moving beneath the glacier gave Thomas some of his most extraordinary sounds. He captured these by recording glacial cracks, sometimes from above and sometimes by dropping microphones into them.

“Water deep down in the cracks wears weird acoustical shapes with the ice, and these change throughout the course of the day,” he says. “It is a very dynamic process and you get lots of crackles, clicks and stuttering sounds as the water resonates in the ice caves. There are even resonant droning pitches that can sound airy and light or deep and ominous. The sound also has multiple layers that you can isolate, with crackles and clicks up top and these deep droning noises below. It sounds like the belly of a spaceship.”

Hydrophones and Glaciers - Thomas Rex Beverly

Thomas tells of one occasion when he and his guides were at the front of a glacier, and they heard a very loud and deep bass sound.

“We felt it first in our chests before we heard it and I thought ‘oh no, do we need to get out of here?’ It was like an earthquake and it set off all my instinctual run reflexes. The guides said it was ok, so we stayed put and tried to find where it was coming from. We stuck our heads into a crack and there was this wild sound coming out of it – like a massive monster breathing. We figured it was a moulin (a mid-glacier waterfall) going into an underwater river and and throwing up big air bubbles that were popping under the glacier. It was wild. It lasted for about 20 minutes and that was it. Glacial sounds can be really transitory and will stop as quickly as they start. I was lucky to be thee at that moment to hear the glacier breathe.”

He adds that the sounds change as the sun goes around the horizon and the deep fjords move into shadow. The water reduces to almost nothing and the sound reduces as well.

“There isn’t a day and night cycle in an arctic summer but the shade means the temperature changes so as the sun comes back, the glacier wakes up and it’s like the dawn chorus,” he says. “The water starts melting again and the sound builds over three or four hours and changes from dripping to gurgles, to cracking and fizzling. The glaciers go to sleep at night and then wake again in the morning. It is fascinating.”

Wildlife and Sled Dogs

Landscapes in East Greenland have almost no vegetation so there is not much for animals on land to eat. This means most wildlife sounds come from seabirds or the occasional arctic fox. Thomas did capture these sounds, including Ptarmigan, which are small arctic ground birds. One curiously investigated his microphone and made many clicks sounding like an alien language, which was a source of much amusement when he played the tape back.

Thomas Rex Beverly Greenland Capturing the sounds of disappearing glaciers

Sled dogs in Greenland

“Most of the wildlife is in the water where there are many species of seals and whales,” he says. “I was pleased not to see a polar bear – we had a rifle with us, just in case!”

He did come across one odd phenomenon – seagulls that had learned to take advantage of glacial calving because the noise of massive pieces of ice falling into the water was enough to shock the fish.

“They would flock to the sea immediately after a large calving event,” he says. “My hypothesis is that the boom of the glacial calving dynamited the fish and the seabirds had learned to listen for the icy thunder as that meant an easy lunch.”

Sled dogs were also a great source of material. The locals keep them for hunting and transportation in the winter when the sea ice is thick enough for sledding – the rest of the year they hunt using boats.

“In Kulusuk there are more dogs than humans – approximately 250 of them,” Thomas explains. “When they all howl at night the sound daisy chains down the valley and they sound like a mega pack of wolves. It is really something to hear.”

Sadly, climate change is having an impact on the future of these dogs as the sea ice, which used to last seven or eight months of the year, now only lasts for four or five and the locals can’t afford to feed animals that are not earning their keep.

“They feed them on seals they have caught, but hunting seals is a lot of work if you only get to use the dogs for four months of the year. So the dog numbers are starting to diminish,” he says. “It will be sad when that part of their culture goes, and it is likely to hit a tipping point in the next decade.”

Climate change is also causing Greenland’s glaciers to disappear. “All of the glaciers I recorded in Greenland are currently retreating at an unprecedented rate and could potentially disappear by the end of this century,” Thomas says. “I hope these sounds help people to love these living rivers of ice. The more people who develop a visceral connection to the beautiful sounds of glaciers, the more likely we are to slow their retreat.”

He adds that he did capture one event that was so massive it was almost biblical.

Disappearing Glaciers Thomas Rex Beverly

“I was in my tent near the calving face of the Knud Glacier and I heard some rumbling that sounded different because it continued for so long,” he explains. “It kept building so I went out and saw an enormous chunk of ice the size of a football stadium or a Manhattan skyscraper break off the glacier. It was so big that it rolled up from the bottom because there was so much ice. It was impressive and beautiful but also bittersweet because you knew that piece was gone forever. That’s partly why I am trying to capture glacier sounds, because I worry that one day they will be gone, and I’d like to ensure we have a record of what they sound like.”

What's next for Thomas?

After nearly three weeks in Greenland during which time he camped near glaciers for days on end and moved around the location in small boats and on foot, Thomas is now back in the USA and facing six months of editing so that he can prepare his recordings for his sound library.

Thomas Rex Beverly

“There is the big high of the trip and then a lot of time in post,” he says. “The reason I have so much editing to do is because it was an unusually amazing trip and I captured so much. Sometimes I am commissioned to do this kind of work but generally it is for my sound library which is purchased by people who want to use the sounds in TV programmes, films, computer games etc.”

For his next trip, Thomas hopes to return to Greenland as he’d like to record whale song, as well as more glaciers. He also wants to record in South America – there are some magical glaciers to explore in Patagonia, he says.

“Each glacier has its own personality,” he says. “They all move at different speeds, have different shapes, different sized crevices and therefore create lots of different sounds. I want to visit more of them. Everyone should try and see a glacier before they die – and icebergs. They are so beautiful. They are awe-inspiring.”

For more information about Thomas and his extraordinary work, please visit his website where you can hear examples of his recordings and access his sound library: