Antarctica in Pictures, Part 4: Making Science

Strike a pose.  Our first day at Schmidt Hills Camp, we climbed up to the western hills, which separated the Schmidt Valley from the Foundation Ice Stream.  The Ice Stream is a super-glacier, a huge current of ice running at a faster speed than the flows to either side.  Its also running south-to-north, while the glaciers that feed it from the Schmidt Hills, Williams Hills, and Neptune Range run more east-west.  Our work would be primarily in these hills and the slopes below.  Crampons, harnesses, and ropes were used to cross the sun-rotted snow along the bergschrund and gain the rock slopes above.  Here, all of us (except for Greg) are trying to emulate the Brits of Antarctica's Heroic Era, who seemed incapable of smiling. | photo Claire Todd

A saddle on a spur ridge, which we cleverly named No Name Spur.  We found erratics on every summit we visited.  This means that the glacier must of been higher than the highest summits in the Schmidt Hills, which was already standing 2000' above the Foundation Ice Stream.  After this photo we climbed up to our first summit of the trip, No Name Peak, visible in the top left.

No Name Spur ran out 4km from the ridge.  The No Name Nunatak, visible to Seth's left, proved to be one of the most important sites for rock samples. | photo Claire Todd

Afterwards we drove around to the western side of the range to take stock of the radar paths and ablation stake sites. | photo Claire Todd 
The Schmidt Loop Trail was actually a horse-shaped track that headed south from camp until it was past the southern-most summit, than curled around and headed back north along the other side of the mountains.  It was flagged every 500m for security, for 22km one way.  Our work could be basically broken into two groups and three objectives:  the Glacier Team was working on Ablation Stakes and Radar Tracks, while the Geology Group worked on collecting Erratic samples.  We repeated this work in the Williams Hills to the south, and in the Web Nunataks to the east.
For GPS elevations to be accurate, a "base station" needs to be established on a fixed chunk of land - preferably bedrock. The flying saucer in the foreground is the GPS antenna, while the electronics are stored in the yellow pellican box they're working on.  The whole unit is powered by a battery/solar system.

Kat's major project was to set up tracks of ablation stakes.  These stakes measure the rate that the surface is added to (accumulation) or retracted from (ablation), giving us an idea of how this area is growing or receding. Ablation stakes are typically set out in a line, or track.
After drilling a hole for the stake, Kat would come back with a GPS unit to mark the exact location.  Now the ablation stake can give her another piece of information - velocity.  When the stake is checked on again, Kat will also do a second GPS tagging, and we'll know what the accumulation/ablation rate and the movement of that particular stake. | photo Kat Huybers
Seth poses for the "Bombardier Boys Calendar."  This shot may make it for "Mr. December". | photo Kat Huybers
Kat's last step is to mark the stake with the track and stake number.  In the end, we put out close to 40 stakes on 4 tracks, totaling almost 20km of distance.  Kat had to tracks at each hill camp.  One track followed the length of one of the east-west glaciers running into the Foundation Ice Stream, and a second shorter track that ran from one of the ridges to the ice stream.
While shooting for the Bombardier calendar was a side job, Seth's actual work on this trip was ground-penetrating radar. Seth works for a not-so-super-secret department of the US Army Corps of Engineers, the Cold Regions Research and Engineering Labratory (CRREL, pronounced "krel").  He's also a geo-sciences doctorate student. | photo Claire Todd

Seth's downward shooting radar could find signs of older glacier features that will help with modeling.  Specifically, when glacial elevations were higher the Ice Stream's shear zone should have been closer to the mountains than it is today, about 4-7km away.  He could also spot features, like deeply covered crevasses, that would help us determine if some of the basins are filled by active, moving glaciers, or by ice fields that were simply left behind as the glacier elevation descended. | photo Kat Huybers
Seth was able to make a fantastic number of radar tracks, including those along Kat's ablation stakes.  A survey-grade GPS was also mounted onto the back of the radar snowmobile to provide a detailed track of Seth's work. | photo Seth Campbell

photo Seth Campbell

With the radar in operation, Seth would ride on the back of the snowmobile staring at a small screen to make sure the radar was operating correctly and the return results were getting recorded.  Meanwhile, I would drive along at 2-3mph along a given track.  The slower we could move, the more points the radar would gather, and the better the images afterwards would be.  Since Seth's work required him to drive far off the flagged routes and close to the crevasse-ridden shear zone, I needed to be his driver most days.  When he could work along a known track - something we had previously driven - he and Kat could work together and I could join Greg, Claire, and Mike.
At the end of the day, Seth was able to look at the radar results on a massive "laptop" computer.  That is an actual radar profile on the screen.
So if Kat and Seth were the "Glacier Team," then Greg, Claire, and Mike were the "Geology Team."  They needed some pretty specific conditions to collect samples.  They needed someplace that had glacially deposited rocks from non-local sources, called erratics.  So these rocks couldn't be of the same type as the bedrock they're walking on in this photo.  They also needed to be reasonably certain that the samples hadn't rolled from uphill, or that the surface hadn't been churned up by freeze-thaw cycles, or that the sample had gotten buried by snow after getting deposited by the
glacier. | photo Claire Todd 
Greg and Claire are geo-chronologists:  they use a particular kind of isotope dating to determine how long a sample has been exposed to the open environment.  When the sample was buried, churned up, and carried inside a glacier it was protected from cosmogenic sources.  Then, when the glacier retreated, it deposited the erratic into the open, exposing it.  Greg and Claire can date how long the sample was exposed for - and therefore how long the glacier hadn't been in that particular spot. | photo Claire Todd

As an undergraduate student at Pacific Lutheran University, Mike was mapping out all signs of previous glacier activity for his final paper.  Here Greg points out a great example of the data Mike was gathering - these are groove lines etched in by rocks dragged along the bottom of a glacier.  So we know which way the glacier was flowing when it was higher than this elevation. | photo Claire Todd

Samples only needed to be fist sized (about 500mL volume or 1kg mass). For Greg's sprectrometer in California.  Sometimes this meant the best samples were too big and a more pack-able sample needed to be hammered
off. | photo Seth Campbell

The location and elevation of each sample was carefully documented and photographed. | photo Claire Todd

This is a typical sample - my booted foot for reference.  The sample has "T 131" on it - the other rock is holding the sample bag down.  The "T" is actually a level/downslope indicator: the cross the "T" is horizontal across the slope, and the stem indicates downhill.

One thing that effects the exposure of each sample is how much of the horizon is interrupted or blocked.  So Mike needed to use an instrument that measured how high a feature rose above the horizon on a compass baring. Claire and Greg will factor these measurements into the results of Greg's labwork measurements later this spring. 

While each sample was GPS tagged and elevation documented, another survey GPS was running at a central location of each sample site.  Typically three to six samples were gathered per site.  So with the handheld, local survey, and base station GPS's to measure against, they will get a very accurate position and elevation marker for each sample.

My science contribution?  My primary job was actually to keep everyone safe so that they could focus on doing their jobs.  But I also gathered weather observations, from 1-3 a day, and flight days I had to report hourly weather to the Weather office in McMurdo. | photo Claire Todd