Thus far I’ve managed to evade discussing much of my work other than a brief, poorly written post awhile back with paragraphs stitched together from broken sentences. I received a few messages from people still confused with what I do, and after 2 months I’m proud to say that I now understand at most 20% of the science behind my ‘job’. How about another science lecture?
Stream Flow. The biggest consumption of our time is spent measuring the amount of water flowing from the glaciers to the lakes. Unlike temperate glaciers, the hydrology (water system) of polar glaciers are such that they are frozen most of the way through, while in temperate glaciers there is an internal system of flowing water. This means that most of the water flowing from a polar glacier comes from the exposed surface of the glacier that is melted by the constant 24-hour sun. This surface water then flows down the side of the glacier (sometimes as dramatic waterfalls) and collects into streams that flow downhill into the lakes of the valley. A separate research group is constantly measuring the mass of these glaciers, and another group is measuring the size of the lakes. The data that we collect can tell you how much of the glacial melt is actually reaching the lake and contributing to the lake’s rise and fall.
As good-looking as a bass fisher
Another way of measuring flow: Acoustic Doppler Velocimeter. Photo Credit: Seth Davidson
To measure stream flow we get dressed up in incredibly sexy hip waders (as worn by such athletic models as sports fishermen) and we hold something called a pygmy meter in the flow. A pygmy meter looks like a small spinning weather vane with cups. It makes a clicking sound with every full rotation. We count the number of clicks per minute or so, and this tells us the velocity of the water. We then measure the width and depth of our stream section to give us total area. Multiply area and velocity and viola! stream discharge. If you graduated 5th grade then you’re completely capable of the calculations we do.
(If you’re currently losing interest with the dry science talk, I can truly promise that it will not get any more interesting. YouTube is just a click away.)
Stream Chemistry. Whenever we visit one of our sites we always collect a water sample for analysis. What we’re looking for are things like nutrients, cations (potassium, sodium, etc), anions (nitrates, sulfates, etc), pH, oxygen content, etc. Sound dull? Check this: the chemistry of streams just a mile apart can be completely different despite coming off the same glacier. What’s more is that a transition in glacier stream chemistry can be detected as we look at streams closer to the ocean vs streams closer inland. For instance: Streams more inland are much higher in nitrates because these chemicals collect from the atmosphere on the polar plateau and gradually move towards the exposed part of the glacier where our streams are. In contrast, streams closer to the sea have higher sulfate levels because the ocean air contributes different chemicals to those glaciers.
Our ultra high-tech lab for filtering water samples
What’s also cool is how the life in a stream can affect the chemistry. Some of our sites have thick algae and moss mats – truly the only visible permanent life in the valleys. This black, orange, or green gunk consumes what limited resources are in the water, so we find very little nitrates in the streams with large algal mats.
Different kinds of algae within our streams. Photo credit: Seth Davidson
Surveying. We have 17 sites in the valleys that have year-round computer monitoring of water height, temperature, conductivity, loneliness, etc. Way back in time (1993 I think) when these sites were installed the original researchers established elevations of the equipment and the stream. Every year during the beginning (November) and end (January) of the season we survey the elevation of our sites. We do this because elevations can change for a number of reasons: ground thaw during November, crazy massive flooding during the summer’s peak, or ground freezing during January/February.
Every guy measures at least once. Photo Credit: Seth Davidson
When we put flow, chemistry, and surveying all together we end up with a fairly good picture of the dynamics of glacial streams. While many of our sites are pretty same-same, certain questions begin to pop up. Why does one stream have huge algal mats while only a half-mile from another that has none? Why does our Blood Falls stream site still flow at -6C water temp, smell like the ocean, and look like carbonated soda? What the hell am I exactly doing here? Many things will remain a mystery, but the exciting parts about science are the cool new doors that one discovery will open up.
For those of you that made it through this I applaude you heartily. I myself fell asleep twice while writing. It’s amazing how comfortable a -40C sleeping bag is with a pack of Chips Ahoy within arm’s reach. Tomorrow is another day of big science. I’m excited.
Hard at work. Photo Credit: Seth Davidson