Tuesday, January 20, 2015

Blood Falls

Picture 1: View of open water to the north in McMurdo 

Picture 2: View of the Ferrar Glacier. The glacier occupies
 the valley immediately to the south of Taylor Valley.
It was nice to catch the last helicopter flight back into McMurdo Saturday evening as it allowed me to get a warm shower and an actual bed for a night before heading back into the field on Monday morning.  There was a noticeable change since the last time I took this flight across the sound.  The edge of the sea ice was clearly visible a couple of miles to the north due to additional melting during these summer months (Picture 1).  Last year there was a substantial amount of sea ice melt and the area in front of McMurdo was completely ice free. This would be great if it happened again because you are able to see whales and adelie penguins when the ice retreats close to the base. Stay tuned!

The Monday morning of my flight back out to the Dry Valleys was probably the clearest day since I’ve been here.  This allowed us to take an uncommon, but highly scenic route to the Dry Valleys.  Upon crossing McMurdo Sound, we took a diagonal flight path across Ferrar Glacier and the Kukri Hills (a mountain range with peaks over 6000ft) to reach the upper end of Taylor Valley (Pictures 2 &3). Both provided spectacular views making this one of the most memorable flights I have ever taken.

Picture #3: View of the Kukri Hills range.
Picture 4: View of Blood Falls.
Our first destination was Blood Falls. This geologic feature is located along the eastern edge of Taylor Glacier and essentially marks the upper end of the unglaciated portion of Taylor Valley (Pictures 4&5). While I have previously seen pictures of this peculiar feature, I was not prepared for its size it is equivalent in height with a five story building! Blood falls gets its appearance from dissolved iron that is being discharged in brines, water that is saltier than the ocean, from the base of the glacier. When in contact with oxygen near the surface the iron oxidizes or reacts with oxygen to form this reddish color material. It is believed this brine was deposited during a previous interglacial period when temperatures where warmer than they are today and a relatively higher ocean filled much of the Taylor Valley and abutted the glacier itself.  It is not yet known what controls the periodic flow from Blood Falls. At the time of our visit it was not flowing so we were only able to see the iron oxide deposits.

Picture 5: Closeup of the iron oxide deposits located at the
base of Blood Falls.
After taking in the sights, it was time to get to work. This trip was a little different than the last one because I was in the role of field hand. Helping others with their research projects is quite normal in the Dry Valleys because projects can be labor intensive, the overall field season is limited time wise due to climate, and you are not allowed to enter remote areas of the field by yourself for safety purposes. 

Therefore, my job today was to assist Dr. Carolyn Dowling, a geochemist from Ball State University in Muncie Indiana (Picture 6). Carolyn is looking at the relative chemical weathering of the soils in Taylor Valey, in other words the of amount chemical alteration that has occurred solely due to the interaction of water with the minerals in the soil. As I previously mentioned water can be a precious commodity in the Dry Valleys; therefore, the longer a soil has been present the more 

Picture 6: View of Dr. Carolyn Dowling and D. Berry
 Lyons hard at work in the field.
Picture 7: View of me sampling Lawson Creek.
extensively it is to have been chemically altered. It is this potential linkage between time and chemical weathering that forms the basis of Carolyn’s project. In each of her sites we collected soils in a transect, or straight line moving directly out from the stream bed. This will allow her to see how shallow groundwater near the stream is also influencing how minerals weather.

An added bonus of this trip was the fact that I got to join a long-term research mentor of mine in the field, Dr. Berry Lyons of The Ohio State University… or should I say the home of the 2015 National College Football Champions!  Dr. Lyons served on my PhD committee at Ohio State and was the one who invited me down here to conduct research in the Dry Valleys (Picture 6). Berry has over 20 years of field deployments in the Dry Valleys so I was excited to ask him questions about so many features and processes in the valleys while we were both witnessing them firsthand. I also appreciated his updates of many individuals I had known from Ohio State and what their projects entailed.

We made a total of two planned stops which also allowed me to collect spot or one-time suspended sediment samples from four different streams, thus adding to my dataset for the year (Picture 7). Unfortunately, it was during our time walking around this second stop that we learned that a storm had moved into McMurdo rather suddenly, which meant that this would not be a day trip after all (This has definitely been an unpredictably stormy and cold season). Fortunately, the Lake Hoare campsite was not too far away and we had a place to stay for the evening. While it meant another night in a tent, it also meant the likelihood of another great meal. We were also joined by several other scientists stranded by the weather. In all, there were a total of 19 people staying at the small campsite. Again, we all made the most of it and had a great evening together.