Saturday, January 29, 2011

Last field day out at the Cotton Glaicer

A lot has happened in the last month or so.  We had 2 more field days at the Cotton Glacier and then we had a hours and hours (did I mention hours!?) of lab work to finish processing the samples and get ready to leave the ice.  I safely made it out of Antarctica and to New Zealand about a week ago.  This week I have been working at the University of Otago, where my adviser is doing his sabbatical.

I have a ton of pics from our last couple of days out that I want to post, so I will attempt a narration about them so it doesn't just look like a random assortment!

The first set of pictures are from our second to last field day out at the Cotton Glacier.  We were collecting enough water to fill 2, 55 gallon drums and 6 20L carboys!  It was a lot of water.  Due to all of the issues with helicopter schedules and getting our gear and all of the empty carboys out to the field, we had the chance to ride out in the Kiwi helicopter (owned by New Zealand).  It's a pretty slick machine!

The Kiwi helicopter -- isn't it beautiful?  They have a contained back rudder and the whole front is a big bubble of glass.  It is so much fun to ride in!!
Once we arrived at the glacier, we went around checking out all of the monitoring equipment that we leave in the field from trip to trip.  The Cotton Glacier meltwater stream is an extremely dynamic system that changes constantly throughout the season.  We hoped to capture these changes using meteorologic data from a weather station, pressure transducers, stream gauging, and plant cameras that collect hourly time elapsed photos.  However, the system was rough on our equipment and we almost lost a lot of the gear.  The picture below is of the met station that was originally installed with about 1.5 feet of clearance before the edge of the ice.  By the end of the season, the ice had melted so much that the station looked like it was about to topple over the edge.
Our meteorological station before we took it down on our second to last field day at the Cotton.  The mountain in the background is called Sperm Bluff because the early explorers thought it looked like a giant sperm whale. 
 After we collected our enormous amount of water (the helicopter pilots are starting to wonder what we are doing with so much water -- they were joking that we started an underground business selling glacial melt water), we had some time to explore and take pictures.  A few weeks before (I didn't go out on this trip), the melt water channel almost completely filled with water.  Based on our plant cam pics, within a few hours of the team's short visit to the glacier, it began to drain and was completely drained by about 6 hours.  It was interesting to see all of the new channels and features that developed as the aftermath of this filling.

 A pretty large river channel through the surface of the cotton.  Just a few weeks before, this whole area was covered in water

 Awesome little sand structures Mike and I found on our walk around some of the sand dunes.  They look like tiny little sand cliffs.
An ice cave Mike discovered in some of his wanderings!
The helo finally picked us up to whisk us back to base.  It was quite a pretty ride home.  This was one of the waterfalls I spotted off the end of a glacier.
Now, the next group of pictures is from our last field day out at the cotton glacier.  Our goals for our last day out were to mostly recover all of our sensors (some were completely buried in sediment from the previous flood on the glacial surface).  When the helo came to pick us up, we were given a little bit of extra time to just fly around the system and get a better idea of what it looks like from the top to the bottom.  The next series of pics are from this recon time.

Columnar basalts on the top of Killer Ridge, which borders the upper part of the Cotton Glacier
Gorgeous blue ice peaking through the sand of the melt water stream in the upper Cotton Glacier channel
Penitene ice in an area of water ponding
Blue ice again in the melt water channel.  It is amazing to think, as we stand on the sand dunes that solid ice lies just below us.  These images of the stream always remind me of that fact and it continues to amaze me.
The lower section of the Cotton Glacier melt water channel
Interesting melting patterns of the ocean ice, taken as we flew back to McMurdo
I am not sure which mountain range this is, but again it was taken on the way back to base
The sun was striking the meltwater channels at a very nice angle

A beautiful sunset to end our last field day.  I took this pic from McMurdo as we headed to the dining hall to catch a late dinner.
Stay tuned for pictures from New Zealand!  I am finally finishing up my work at the University of Otago this week and am ready for a long awaited vacation!

Sunday, January 9, 2011

Camp Pull-out From Frxyell

I am a bit behind in my entries, since our Camp Pull-out from Frxyell actually occurred just before the new year, but I realized I have one more video (sorry I didn't take more Jeevan!) and a few more pics from our last day at Frxyell. 

At Frxyell, since the ice cover never completely disappears, we often traveled across the lake ice on four wheelers.  We travel across the moat (where the lake ice melts at the edge of the lake), by a small boat to our four wheeler.  It can be quite an adventure to get across the lake!  Contrary to what I initially thought, the lake ice surface is anything but flat!  Solar irradation, sublimation, refreezing of the ice causes the formation of trenches and piles of ice.  Much of the lake ice is composed of a particular ice known as penitentes.  These long blades of ice form with their long axis generally oriented to point toward the sun.  They make a beautiful tinkling noise when stepped on and sound a little like wind chimes!  You can kinda hear it in the video I took of Heidi walking in circles around me ;-).
video

We left Frxyell in a whorl wind of packing up labs, tents, and personal gear.  We have so much science equiptment (in addition to our personal gear), it took 3 helicopters to get us and all of our stuff out of camp!  The helo pilot of the last helicopter that came to pick us and our last load of gear up took one look at our giant pile of bags, shook his head, and said, "Wow, you can really tell that your group is all women!"  (We did have Mike with us as well, but we had managed to convince him to paint his fingernails with us for Christmas -- so I think he was including Mike in this assessment!).

 AStar-B2 Helicopter with one of 3 of our giant white boxes taking off with the sling load.

However, with 3 giant white boxes slung under 2 helicopters (2 stacked and then 1 single sling load), and a VERY full Bell 212 helicopter, we managed to pull out from Frxyell -- only forgetting a pair of hiking boots (not mine, I promise!).


Lake Frxyell from inside the Helicopter


Say goodbye to Lake Frxyell Camp!


Beautiful frost-heave pentagons

The frost-heave pentagons form due to the freezing and thawing of the permafrost.  I don't fully understand the actual mechanisms behind the formation of frost-heave wedges since there seems to be several different hypotheses and many important little details.  However, in short these often form in permafrost and are the result of the expansion of water as it freezes in a constrained setting.

The volcano, Mt. Erabus, taken from the Helo as we fly back to McMurdo

Since leaving Frxyell, we have been doing tons of lab work -- trying to process all of our samples, unpack from the field, and repack for our upcoming departure!  Two days after we returned to McMurdo, we headed out to the Cotton Glacier for our second to last field day out at the Cotton Glacier!  It was a blast to do --- I'll get the pics and more posted soon!

Monday, January 3, 2011

Happy New Years!

So we have been back in McMurdo for a few days now, working away to get all of our samples processed.  However, I was so busy while out at Frxyell (and the past few days), I have tons of pic I wanted to post ages ago!  To start off the new year, I thought I should clean out some of my back-log of pictures.

Before we headed out to Lake Bonney and Lake Hoare for Christmas, we were visited by the Santa flight!  This flight visits all of the field camps and brings a Christmas box with wonderful snacks that we don't normally get in the field -- among other things, our box had gourmet cheeses, fresh peppers, and grapefruits!!  We were all really excited for the "freshies"!!  The flight also gives some of the permanent McMurdo employees an opportunity to visit the field sites, which they otherwise would not get to do.  There was much anticipation to the flight and it was a lot of fun meeting everyone!
Santa Flight!

Next group of pics up is the Limnology Hole:

These are a couple pictures of the limnology drill hole (referred to as the "limno hole" here), which the Long Term Ecologic Research (LTER) project uses to study the chemistry and biology of lake Frxyell.  We had the opportunity to sample from the hole that Heidi will use to look at the microbial population of the lake to compare it to the supraglacial population of Canada Glacier that flows into the lake.

The hole doesn't completely re-freeze overnight, but with a few days of no sampling, a sheet of ice tends to form over the top of the lake water.  So to sample, you have to break up the ice with an ice chipper and then use the scoop to pull all the ice out of the hole (This is what Heidi is doing in the pic to the left).

The hole i actually quite beautiful.  The ice is so blue!  Below are just a few pics looking down through the lake ice...  


Looking down the limno hole

Close-up of ice at the top of the limno hole
To sample the hole we use a device called a Niskin water sampler (aka. Van Dorn water sampler).  The Niskin is basically a tube with spring loaded caps at either end.  When the sampler is lowered to the desired depth, we drop a weight down the feed line that triggers the caps to close.  That way we can collect water from different depths in the lake!


Our Niskin sampler going down the hole!
Also as promised, I wanted to post more pics from our hike on Christmas from Lake Bonney to Lake Hoare.  It was so much fun!  There were many amazing sights throughout the hike.  For a little orientation, below is a satellite image of the Taylor Valley with the major lakes and glaciers labeled.  We started at Lake Bonney Field camp (located about 6:00 on the image of the lake below) and hiked toward lake Hoare around the Seuss Glacier.  The day after Christmas, we hiked back over the Canada Glacier to our camp at Lake Fryxell!

Satellite image of Taylor Valley (Image From Wikipedia)
Throughout the hike way we saw 10 or so mummified seal carcasses, which are common throughout the valley.  Apparently, the seals come inland to mate, but get lost and instead of heading back out to sea, move inland.  They sadly eventually die of starvation and the carcasses are preserved for hundreds of years afterwards because of to the cold temperatures and dry climate.

A mummified Seal Carcass
Frost heave wedges forming organized cracks throughout the permafrost
A view looking up-valley toward the Taylor glacier

The glaciers pulverize the rock material into a fine dust which makes many of the lakes have a brilliant blue coloring

The edge of the Seuss Glacier looking toward Lake Hoar

The melting edge of the Seuss Glacier looking out back up Valley
Posing of Lake Hoare!!!  We made it!!