24 hours of the sun circling over our field camp. I haven’t seen darkness in three months. I love it.
Some of our stream sites are gauged only once a season because of their unique location. This last week we had the chance to go to one of the more remote and less visited valleys of the region: Miers Valley. As we headed south from our field camp our helo pilot informed us that we were the first American group he’d heard of to visit Miers this year (there’s a small isolated Kiwi camp of 4 researchers at the head of the valley).
We broke up into two teams for our visit. The first was dropped off at the west end of lake where the major stream system enters. They were to measure the amount of water going into the lake, while I was dropped off at the other end of the lake to measure how much water was leaving.
Miers is a much smaller valley than Taylor (where I live); roughly 1/3 the size. Being further south it has a phenomenal view of the Royal Society Mountain Range which acts as a protective barrier to keep the East Antarctic Ice Sheet at bay. The visual feature defining Miers are the two glaciers that form a crescent at the beginning of the valley. These glaciers are actually flowing in a curved rather than straight direction.
As our short three hours in Miers came to a close, I noticed the remnants of an old field camp site. Cairns marked a historic science site and footprints ringed a flattened patch of disturbed gravel where a tent used to be.
Since we’ve been hiking a lot this season to conserve helo hours, we also had the chance to get an extra set of measurements and explore a bit more of a valley I described a few posts back: Garwood Valley. The major feature of Garwood is a subterranean river that cuts through the bottom of a glacier and winds under the Earth to emerge at odd intervals down valley. Our first visit to the valley was exploratory in every sense of the word – we were dropped off at an arbitrary location, had vague GPS coordinates of where the valley was measured years before, and had nothing but our feet and a profound lack of a direction to guide us.
On our second time through we were prepared with recent GPS locations and my faltering memory to ensure that we were measuring the exact same spots as earlier in the season (replication is the key to data collection). As I held the GPS upside-down and wandered along the length of the river, I came across a section that I hadn’t seen previously: the spot where the river dives down into the Earth and becomes subterranean for the first time. It was epic.
The river cut jagged walls in the dirt leaving exposed boulders that fell apart as I stood there. It descended 30 feet straight down and the waterfall’s mist created huge 6 to 10 foot icicles that lined the cavern’s entrance. It was the single most impressive river site I’ve seen down here.
My final photo below wasn’t taken in either Miers or Garwood Valley, but rather was shot when I was out doing some deconstruction near Taylor Glacier this weekend. As my teammate and I were disassembling an old stream gauge he noticed a small face peering out of the moraine. An old seal mummy was being buried underneath the accumulating boulders and gravel that collect at the end of Taylor Glacier. Only the jaws remained exposed. Even as I took the picture sand and rubble were coming down the edge of the moraine making it clear that this would be the the last time that the several hundred year old corpse would be seen.
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.
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.
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.
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.
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.
The dynamic movements of ice on the continent create staggeringly gorgeous formations. While I am currently surrounded by glaciers and frozen lakes, I was able to catch a glimpse of a different kind of ice sculpture earlier this season.
Around the coast of Antarctica there are many areas where the permanent ice shelves of the continent meet the winter sea ice of the ocean. Pressure ridges form during the repeated heating and cooling of the surface of the ice. The meeting of the ice shelves and the sea ice is the perfect breeding ground for these jagged ridges.
I took a walk to an undisclosed location. Without breaking any rules whatsoever, I was lucky enough to snap a few photos of my short jaunt.
Our internet (and communication in general) has been out for the last week, preventing me from updating as frequently. Sadly it looks like we will continue to have trouble with it until the end of the season, but I will be doing my best to post again soon this weekend. It’s tricky.
We had an arrival of 6 guests at our 3 person camp for this last week, making the total population of our little commune nine. For the last three days snow has fallen over the valleys and on McMurdo Station: 11-hour flights from Christchurch have boomeranged, helicopters have been stranded at field camps for two days in a row, and communication lines have failed daily. This week has been utter chaos.
But it has been incredibly enjoyable. With the arrival of visiting scientists we’ve had a fresh change of faces and new conversation, accompanied by the overwhelming sense of sitting in a burning building while being unable to escape. It’s a bit like having Thanksgiving dinner with your entire extended family.
Upon entering our camp and seeing me for the first time since September, one of our visitors said “Holy hell, you look like a pirate.” As I blushed from what I will interpret as a compliment, I soon realized he could have equivalently meant “Holy hell, what a train wreck”.
It’s officially been two months since I entered the field. I’ve travelled a bit in the last two years and my current tent will be the most consistent place I’ve lived in during this period. My sleeping bag is as comfortable as any mattress, I put on the same set of clothes for two weeks without thinking twice, and I don’t feel as much discomfort working in the cold. But I’ve also become accustomed to things I wish I hadn’t. The glaciers I wake up to in the morning have become as regular as a cityscape and the 24-hour sun feels natural and as if nothing’s amiss. After only two months it’s difficult to keep fresh eyes for a place that I feel quite at home in. But while I have become spoiled in beautiful scenery, it has allowed me to put down my camera for once and I’m able to enjoy a hot coffee while I sit outside and watch the ice melt.
With two months finished I sit here thinking that the time is passing too quickly. I have only a month left and nights are spent plotting ways to return for another season. It will be hard to leave.
Last week we had the chance to visit one of our more remote and less visited sites: Garwood Valley. Located 30 minutes fly time south of Taylor Valley, it’s significantly smaller and quite distinct from the place we live. To get to Garwood we fly over the Kukri Hills that form the southern border of Taylor Valley and descend upon the massive Ferrar Glacier.
The Dry Valleys are located next to the immensely long Trans-Antarctic Mountain Range that divides the entire continent into West and East Antarctica. The East Antarctic Ice Sheet is the world’s largest piece of ice, and the Trans Antarctic Range prevents this sheet from moving into the valleys for the most part, keeping the Dry Valleys dry. The Ferrar Glacier is actually a lobe of the East Antarctic Ice Sheet protruding through the Royal Society Mountains (what we call this part of the Trans-Antarctic Range). The glacier is so large that rivers and lakes exist on its surface and are easily seen from a helicopter.
After descending a mountain range not named on my map, we landed at Lake Colleen in Garwood Valley. The only place of residence is a small, uninhabited field camp run by the Kiwis by the side of the lake.
Garwood is a seldom visited valley and has remained in pristine condition due to the relative lack of science that occurs there. Our team has historically sampled this site only once a year, so it was a privilege grab a flight out that day. My teammate and I were dropped off at the upper end of the valley; our plan was to hike around the terminus of Garwood Glacier and follow the river down the entire length of the valley to the ocean. As the helo took off it was an incredible feeling to be alone, able to walk through an area that few will get to see.
The ‘river’ that we followed was relatively powerful compared to the small streams that we’ve been gauging this season. Garwood Stream is the most unique feature of this valley – it goes subterranean. Twice. It winds along on top of the ground for several miles but as it approaches Garwood glacier it cuts into the side of it and disappears underneath. The stream flows through the bottom of the glacier. As we walked near the edge of the ice, we could hear the raging water echoing from within the glacier. It sounded like a massive cavern was being carved into the ice. The stream emerged at the other end of the glacier’s terminus for a brief 300 hundred meters before vanishing again, this time into a large dune of dirt.
I’ve been told that a few years back a massive landslide covered the stream. Eventually, the water eroded the bottom layer of soil and created a tunnel underneath. One of our sample sites is where the stream reemerged as a thick brown gush of water.
Our 5-hour hike was extraordinarily pleasant. The only bit of drama occurred when we were walking along the loose boulders of the glacier’s moraine (a moraine is a buildup of dirt and rocks that the glacier deposits in front of it as it recedes. Glaciers act like large conveyor belts.) I stepped on top of what looked like a solidly placed rock, but the soil underneath shifted and the boulder rolled. I fell onto a soft, pointed rock, breaking my fall with my ribs. After a few minutes of massaging a bruised chest but an even more wounded ego we continued on.
As our time in Garwood was coming to a close we came across a relatively rare sight in the Dry Valleys – a mummified penguin. Penguins are actually much more likely to enter the valleys than seals. However, their skin is much softer than seals so when they die their bodies are picked apart by skuas and are much more susceptible to weathering. So while it’s not uncommon to find penguin skeletons, it much less likely to come across a penguin with mummified strips of flesh. What a treat.