Operation Iceberg: Helen Czerski's blog from the Arctic

Ask a child to draw a lake, and they will use a blue crayon. Bright blue. And the same goes for the ocean or water in the bath. But that’s odd, isn’t it? Lakes are brown-ish, green-ish or at their best, blue-ish. Our mental image is of something we’ve never seen. But two weeks ago, I stepped out of a helicopter on to a glacier and just in front of me was the azure lake of my childhood artwork. It was as if someone had poured the world’s supply of blue food dye on to the ice.

The crystal blue waters of the Artic Ocean (credit: Helen Czerski)
 

This spectacular sight was the start of our scientific journey on the Store glacier in Greenland for the BBC Two series Operation Iceberg. There are many of these lakes up on the glacier, formed as the summer Sun melts the surface ice and the meltwater droplets find their way down into the nearest hollow. As the season goes on, the lakes grow. We were clambering about over the lumpy ice to install water level sensors and a time-lapse camera to monitor that growth. And it is just water – the sensational blue colour is the result of a very pure situation. Water absorbs red quickly, and green light nearly as quickly, leaving the blue wavelengths until last. Since there’s only reflective white ice on the lake floor, the light that finds its way back out of the lake is almost perfect blue.
 

The lakes don’t last. The glacier is a moving fortress of ice, constantly shuffling and creaking as it marches from the centre of the Greenland ice cap downwards towards the ocean. As it goes, immense internal forces can open up crevasses and fractures. If this happens at the floor of a lake, it’s like pulling the plug in the bath. The entire lake disappears down the plug hole and into the glacier. So of course, while we were interested in the lake growing, there was also the tantalising (and dangerous) possibility that it would start to drain while we were there. I have never before spent a morning keeping an eye on a lake in case it runs away, and it definitely made me feel very small and vulnerable.
 

The mosquitoes, on the other hand, made me feel very large and vulnerable. My skin is a gourmet dinner buffet for an Arctic mosquito, even when I’m covered in many layers of clothes. We spent three weeks camping on a small rocky plateau overlooking the front of the glacier, and on the still days we all felt like pin cushions. Apart from the occasional hare and the increasingly nosey Arctic foxes, we were the only mammals there and our small buzzing companions took full advantage. At least we gave something back to the local ecological economy.

Artic Fox Cubs join the team for lunch (credit: Helen Czerski)
 

Every iceberg has a long history, and that history always starts at a glacier. We were at Store to follow and help with the ongoing scientific experiments that are revealing the details of iceberg formation. Our campsite felt like a tiny but very multidisciplinary village, with about 20 production crew, scientists and presenters. The kitchen tent had a prime spot overlooking the white cliffs of ice where the glacier met the sea, and at mealtimes everyone would perch on the rock next to it to eat.

 

The lifestyle was fairly primitive, but the setting was spectacular. The glacier squeaks, creaks and booms as it shuffles along, and we would often see mini avalanches of ice tumble off the front and into the water. Sometimes these heralded much larger calving events, as vast chunks of solid ice separated from the cliffs and started their journey out to sea. Dinnertime entertainment was mixed with professional interest, as we kept an eye out for the event we really wanted to see – the calving of one of the largest icebergs that Store glacier can produce.

Operation Iceberg will be a two-part series, and the first programme covers the glacial science leading to iceberg formation. The topic of the second programme is icebergs at sea, and how these behemoths of the ocean eventually break up and melt away. The best bit about this for me is that I get to help with the research as well as being a presenter. This project is a really interesting and symbiotic collaboration between researchers and programme-makers – neither would be here without the other.

I study the physics of the ocean but I have also worked on the physics of materials, so an iceberg has the perfect subject combination for me. I love the idea that there are hidden processes just underneath the surface of familiar objects, and this project is keeping me happy because ice is full of hidden mysteries.
 

Some of the processes influencing iceberg formation start many kilometres up the glacier. When you’re on the ice, hints about the complexity of what you’re standing on are everywhere. My two favourite things were the very blue streams of melt water, and some lovely things called cryoconite holes. The meltwater streams snake around like water slides before suddenly disappearing down into deep holes, gateways to the internal plumbing of the glacier. The cryoconite holes are beautiful pockets in the ice, reminiscent of the holes in Swiss cheese. At the bottom of each one lies a black layer of volcanic dust, which is responsible for the hole it’s in. The black dust absorbs more of the Sun’s energy than the ice, warms up and melts itself a perfectly-shaped deep hole. It’s a stunning demonstration of how an object’s colour controls how well it absorbs energy from the Sun.

 

Helen sat with some cryoconite holes (credit: Helen Czerski)
 

The blue lakes aren’t just pretty cartoons come to life. They are one of the many cogs in the fascinating machine of glacial mechanics. My three weeks on Store glacier changed my perspective on icebergs almost completely. Did the lake drain away? Did we see a giant iceberg calving? You’ll just have to tune in to Operation Iceberg to find out.