Flying Over Blue Lakes, 5 July
Washing my hair in a bucket last night, I felt that I had come to the decadent end of a luxurious day. I’m not exaggerating or being ironic. Yesterday was indeed luxurious, and there wasn’t a Faberge egg or a Michelin chef in sight.
Helen at a blue lake
The task for the day was to film at a blue lake, high up on the glacier. These are pools of meltwater that fill huge hollows in the ice. You’d think that water on top of ice might be hard to spot from a distance, but these pools advertise themselves in a spectacular way. They are the deepest, purest and most surprising bright blue I’ve ever seen.
Flying over the ice, everything is white. Near the mouth of the glacier, the surface is crumpled and fractured, so it has lots of texture, but it’s all very bright white. And then you see a dark streak which gets more blue as you get closer until it looks exactly as though someone had just poured a few tonnes of blue food dye on to the ice. It’s startling. The colour comes from a very common bit of physics happening in a very extreme environment. Water absorbs more red light than green light, and more green light than blue light. White light comes from the sun into the lake, and the red light and green light are all absorbed, leaving only blue behind. The blue light is scattered instead of absorbed, so it bounces around inside the water until it eventually finds its way back out and into your eyes. There’s nothing else underneath or in the water that absorbs light significantly, so it’s a very simple situation. It’s such pure blue on such a large scale that it really does look artificial.
We were filming the placement of some scientific instruments which monitor the lakes filling and draining. We all helped with the surface instruments and then Andy Torbet and Doug Allen went into the lake with SCUBA apparatus to put sensors beneath the surface. After ten hours on the ice, we came back to base camp, happy with a good day’s work.
And then it got even better. Later, on, we were all standing just outside the kitchen tent eating dinner, when an unusually long rumble from the glacier made us look up. We’ve got used to the bangs and groans as the ice moves and as bits fall off the front, but this one was different. Over the course of about ten minutes, an entire ice promontory a kilometre across split away, turned over in the water and marched off down the fjord, banging and popping and roaring as it broke apart. To say we were gobsmacked doesn’t even come close. I’ll write more about iceberg formation in another blog, but once our excited shouts died down, the scale of this single event gave all of us a lot more respect for the environment we’re working in.
After the excitement, I decided it was a good time to wash my hair. So I carted a bucket up the hill to a nearby lake with an even better view and no mosquitoes. A perturbed ptarmigan gave me some grief on the way up, but apart from that there was just peace and quiet and a very grand view. There was a grassy bank covered with flowers where I parked my bucket once I’d filled it from the lake. Blue lakes and icebergs... what a privilege. And clean(er) hair to boot. Couldn’t be better.
